TW202313447A - Waterproof mems pressure sensor package with a metal lid and an embedded eptfe filter and process of making - Google Patents

Abstract

Microelectromechanical system (MEMS) packages and methods of making thereof. A MEMS package includes at least one MEMS device disposed on a base substrate and a lid disposed on the base substrate. The lid is configured to enclose the at least one MEMS device. The lid includes a body portion configured to be coupled to the base substrate, a ceiling portion and a membrane. The ceiling portion, the body portion and the ceiling portion form a cavity in which the at least one MEMS device is enclosed. The membrane is configured to be in contact with the ceiling portion. The membrane is formed from a filtering fabric and is configured to substantially block one or more of liquids and contaminants from passing into the cavity.

Description

Waterproof MEMS pressure sensor package with metal lid and embedded ePTFE filter and method of manufacturing the same

The present invention generally relates to microelectromechanical systems (MEMS) sensors that can be used in various device types, including wearable devices, and in various application types, including a pressure sensor package. In particular, the present invention relates to MEMS device packaging and methods of manufacturing the same for protecting MEMS sensors from the environment.

A MEMS device may include a dedicated package, which may depend, for example, on the type of device and/or application. For example, a MEMS device such as a pressure sensor may include a package to house one or more pressure ports such that a membrane of the pressure sensor may be exposed to an ambient (external) environment. However, other components of the package (such as an integrated circuit, electrical connectors, pads, etc.) may require protection from the external environment (eg, water and/or other contamination).

In conventional solutions, a waterproof MEMS package is usually provided. In some known solutions, waterproofing (and environmental protection) is provided by covering the MEMS device with an adhesive package. However, the presence of adhesive (eg, on a membrane of a pressure sensor) can affect the sensitivity performance of the device and/or can affect the handling of (adhesive-filled) components. Therefore, the conventional waterproof MEMS package with an adhesive will limit the maximum performance of the device product.

Therefore, there is a need for MEMS device packaging with improved environmental protection.

Aspects of the present invention relate to a MEMS pressure sensor package and a method of manufacturing such a package that provide improved protection against water and contamination.

In some embodiments, the present invention provides a MEMS sensor package that protects the MEMS pressure sensor membrane from liquids and/or contamination that can damage the sensor and affect its performance.

In some embodiments, the present invention discloses a microelectromechanical system (MEMS) package comprising: at least one MEMS device disposed on a base substrate; and a lid disposed on the base substrate, the lid configured to enclose the at least one MEMS device. In some embodiments, the cover includes a body portion configured to be coupled to the base substrate, a top portion, and a membrane configured to contact the top portion. In some embodiments, the body portion and the top plate portion form a cavity encapsulating at least one MEMS device. In some embodiments, the membrane is formed from a filter fabric. The membrane is configured to substantially block one or more liquids and contamination from entering the cavity.

In some embodiments, the roof portion includes a roof layer, and the film is configured to be adhered to the roof layer. In other embodiments, the top deck portion includes first and second top deck layers, the membrane is configured to be embedded between the first and second top deck layers, and the top deck portion is configured to be coupled to the main part. In some embodiments, the main body portion and the top plate portion are formed as a single-piece structure.

In some embodiments, the MEMS package may further include at least one of a hydrophobic coating and an oleophobic coating disposed on the filter fabric. In some embodiments, the top plate portion may include one or more holes. Additionally, the membrane can be configured to cover one or more holes of the top plate portion.

In some embodiments, the filter fabric may comprise an expanded polytetrafluoroethylene (ePTFE) material. In some embodiments, the cover may be formed from a conductive material including a metal. Additionally, the metal may include one or more of stainless steel, brass plating, aluminum plating, and nickel. In some embodiments, the at least one MEMS device includes at least one MEMS pressure sensor. In some embodiments, the membrane is configured to provide at least one of waterproofing and contamination protection of the at least one MEMS device. In some embodiments, the body portion can include an annular ring, and the top plate portion can include a disk.

In another aspect, the present invention discloses a method of fabricating a MEMS package. In one embodiment, a method of manufacturing a microelectromechanical system (MEMS) package is provided, comprising: forming a lid including a body portion and a top plate portion such that the body portion and the top plate portion form a cavity, at least one of which The MEMS device is configured to be enclosed in the cavity; a membrane is formed from a filter fabric; the membrane is placed on the top plate portion such that the membrane is in contact with the top plate portion, the membrane is configured to substantially block one or more liquids and contaminations enter the cavity; and disposing the cover on the base substrate such that the body portion of the cover is coupled to the base substrate, the base substrate including at least one MEMS device disposed thereon.

In some embodiments, forming the cover further includes forming the body portion and the top plate portion as a single-piece structure, and adhering the film to the top plate portion.

In other embodiments, forming the lid further includes providing first and second top sheet layers, the first and second top sheet layers forming a top sheet portion; and coupling the top sheet portion to the body portion, wherein positioning the membrane further includes The membrane is embedded between the first top ply and the second top ply. Additionally, in some embodiments, the first and second top plies may be adhered together without adhering the film to the first and second top plies. Additionally, in other embodiments, the film may be adhered to one or more of the first and second top sheet layers.

In some embodiments, the method can further include disposing at least one of a hydrophobic coating and an oleophobic coating on the filter fabric. In some embodiments, the method can further include forming one or more apertures in the roof portion, wherein the membrane is configured to cover the one or more apertures in the roof portion. In some embodiments, the filter fabric may comprise an ePTFE material.

In some embodiments, the cover may be formed from a material including one or more of a metal and a polymer. Additionally, the metal may include one or more of stainless steel, brass plated, aluminum plated, and nickel.

In another aspect, the present invention discloses a method of manufacturing a plurality of housing packages. In one embodiment, a method of manufacturing a plurality of housing packages is provided, wherein each housing package is configured to package a microelectromechanical system (MEMS) device, comprising: providing one of the substrates having a first top plate assembly A first top plate layer, each of the first top plate components having one or more first holes configured in a first pattern; providing a second top plate layer having a substrate of a second top plate component, of which the second top plate components each having one or more second holes configured in a first pattern; providing a membrane layer comprising a filter fabric; embedding the membrane layer between the first top layer and the second top layer such that aligning the substrate of the first top panel component with the substrate of the second top panel assembly to form a third top panel layer; separating the third top panel layer to form a plurality of top panel sections corresponding to the plurality of housing packages; and coupling the plurality of top plate portions to the plurality of base portions to form the plurality of housing packages.

In some embodiments, the embedding of the film further comprises adhering the film layer to each of the first top layer and the second top layer. In other embodiments, the embedding of the film further comprises: one or more third holes in the film configured in a second pattern, the second pattern being different from the first pattern; according to the second pattern disposing an adhesive on one of the first top layer and the second top layer; and adhering the first top layer to the second top layer via the one or more third holes of the film according to the adhesive layer.

In some embodiments, the filter fabric includes an ePTFE material. In some embodiments, each of the first top layer, the second layer, and the plurality of base portions are formed of a metallic material including one or more of stainless steel, brass plating, aluminum plating, and nickel. In some embodiments, the method further includes disposing at least one of a hydrophobic coating and an oleophobic coating on at least a portion of the filter fabric.

Cross References to Related Applications

This application claims priority to U.S. Provisional Application No. 63/245,715, filed September 17, 2021, and U.S. Patent Application No. 17/733,720, filed April 29, 2022, the full texts of which Incorporated by reference.

As mentioned above, it is desirable to form MEMS devices (eg, MEMS sensors) to protect them from the environment. For example, it may be desirable to protect a MEMS pressure sensor membrane from liquids and/or contamination that can damage the sensor and affect its performance. Therefore, it is important to provide robust techniques and methods for waterproofing a pressure sensor package.

Referring to FIG. 1 , there is shown a cross-sectional view of one of a prior art MEMS sensor package 100 (referred to herein as a conventional package 100 ). In general, a conventional package 100 may include a MEMS sensor 102 disposed on a base substrate 104 . MEMS sensor 102 may be enclosed by a cover 106 coupled to base substrate 104 . In some examples, cover 106 may include one or more apertures (not shown) that may form port(s) to an external environment. Conventional package 100 may be filled with adhesive 108 to provide waterproofing of components within package 100 . Adhesive 108 is typically positioned in a manner to cover MEMS sensor 102 (and any other components (not shown), such as any integrated circuits, bond pads, bond wires, connectors, and the like). In general, glue 108 may comprise an adhesive compound and represents an example of a potting material that may be used to encapsulate electronic components. In a non-limiting example, the adhesive 108 may comprise a potting adhesive manufactured by Shin-Etsu, such as SIFEL® 8470.

In conventional packages 100 , the adhesive 108 (typically) completely covers one of the exposed surfaces of the MEMS sensor 102 . However, since the adhesive 108 covers a surface of the MEMS sensor 102 (e.g., a film of a pressure sensor) to be exposed to the external environment, the adhesive 108 can affect the sensitivity performance of the MEMS sensor 102 (e.g., , the sensitivity of gravity (g)-pressure sensitivity). For example, the glue 108 introduces an extra pressure on the membrane of the MEMS sensor 102 (eg, due in part to the thickness and density of the glue 108 on the membrane and the density of the glue 108), thereby reducing the membrane's ability to respond to pressure changes. ability. Thus, this extra pressure can reduce the g-sensitivity of the membrane and cause a delayed response time by the MEMS sensor 102 (eg, when the MEMS sensor 102 is inverted). Therefore, the glue 108 can negatively impact the performance of the MEMS sensor 102 . Additionally, users may have concerns about handling the adhesive-filled components of conventional packages 100 (eg, due to the texture of the adhesive 108 and/or any other concerns). For example, a surface of the adhesive 108 may pick up dust and/or contamination from the environment and/or during use. This change in appearance over time may raise concerns about the quality (eg, performance, durability, etc.) of MEMS sensor 102 and/or package 100 itself.

Aspects of the present invention relate to MEMS packages and methods of fabrication thereof. In some examples, a MEMS package can include at least one MEMS device disposed on a base substrate and a lid disposed on the base substrate. The cover can be configured to enclose the MEMS device(s). In some embodiments, the lid can include a body portion configured to be coupled to the base substrate, a top portion, and a membrane configured to contact the top portion. In some embodiments, the body portion and the top plate portion may form a cavity in which MEMS device(s) may be packaged. In some embodiments, the membrane may be formed from a filter fabric. The membrane can be configured to substantially block one or more liquids and contamination from entering the cavity. In some embodiments, the filter fabric can be formed from an ePTFE material (referred to herein as an ePTFE membrane). In some embodiments, the MEMS device(s) may include a MEMS pressure sensor. In some embodiments, the MEMS package may include one or more holes in the top plate portion (eg, to form one or more ports to an external environment). The filter fabric can provide waterproofing and/or contamination protection of the MEMS device(s) by covering the hole(s) to prevent fluid and/or other containers from entering, while still allowing the MEMS sensors to be exposed to the external environment.

In some embodiments of the invention, the roof portion may comprise at least one roof layer in contact with the membrane. In some examples, the cover can be formed as a single monolithic component such that the top plate portion and the body portion are a unitary structure. In some examples, the top plate portion can be a separate component of the body portion, and the top plate portion can be coupled to the body portion (eg, press into the lid body portion). In some examples, the roof portion can include a top roof layer and a bottom roof layer with the membrane (eg, formed of a filter fabric) embedded therebetween.

Compared with conventional packages, the MEMS package of the present invention does not use an adhesive in the package cavity to cover the MEMS device. In contrast, example MEMS packages of the present invention may embed (and/or adhere) the film into a top plate portion of the lid (e.g., by embedding the film between the top plate portion and the bottom top plate layer, or within a monolithic lid In this case by adhering the membrane to the top layer). Using an ePTFE film (for example) instead of an adhesive provides advantages over conventional packaging, including improved sensitivity performance (e.g., g-sensitivity performance, membrane sensitivity performance), and may allow protection of MEMS devices (e.g., pressure sensing detector) from possible damage during cover handling.

In some examples, the MEMS package of the present invention can be used with one or more MEMS pressure sensors. In some examples, the MEMS packages of the present invention can be used in MEMS pressure sensors. In general, the MEMS package of the present invention can be used with any MEMS pressure sensor. Furthermore, although examples of MEMS packages of the present invention are described with respect to MEMS pressure sensors, MEMS packages are not limited to MEMS pressure sensors. In general, the MEMS package of the present invention can be configured to be used with any MEMS device, including a MEMS device that includes a sensor that is exposed to the (external) environment.

Reference is next made to FIGS. 2-6 . An example lid 200 of a MEMS package 500 is shown according to an aspect of the invention. Specifically, FIG. 2 is a perspective view of the cover 200; FIG. 3 is an exploded perspective view of the cover 200; FIG. 4A is a cross-sectional view of the cover 200; FIG. 4B is a cross-sectional perspective view of the cover 200; is a perspective view of an example MEMS package 500 ; FIG. 6 is a cross-sectional perspective view of a MEMS package 500 .

Next, the cover 200 will be described with respect to FIGS. 2 to 4B . Cover 200 may include a main body portion 202 and a top plate portion 204 . The body portion 202 may include a sidewall region 402, a top portion region 404, and a base portion region 406 (FIG. 4A). The body portion 202 may be configured to be coupled to the top portion 204 near the top portion region 404 . Body portion 202 may also be further configured to be coupled to base substrate 502 via base region 406 (FIG. 5). When the body portion 202 is coupled to the top plate portion 204, the combination can be configured to form a cavity 408 therein.

In some examples, the base portion 202 can be configured as an annular ring and the top plate portion 204 can be configured as a disk with a cylindrical cavity 408 formed therein. It should be appreciated that the shape of cover 200 (and cover 702 shown in FIGS. 7A-8B and cover 918 shown in FIG. 9F ) represents a non-limiting example, and that cover 200 (702, 918) can be formed from any suitable symmetrical shape. (eg, cylinder, cube, cuboid, etc.) and/or any suitable asymmetric shape.

As best shown in FIGS. 3 and 4A , the roof portion 204 may include a first roof layer 302 - 1 , a second roof layer 302 - 2 and a membrane 304 embedded therebetween. Membrane 304 may be formed from a filter fabric and may be configured to substantially block one or more of liquid (eg, water) and contamination (eg, particles) from entering cavity 408 and penetrating package 500 . In some embodiments, the filter fabric may comprise any suitable ePTFE material. In some examples, at least one of a hydrophobic coating and an oleophobic coating may be disposed on the filter fabric forming membrane 304 .

In some examples, the membrane 304 can include one or more holes 310 (one hole depicted in FIG. 3 and several holes 910 shown in FIG. 10C ) arranged in a predetermined pattern. In some examples, membrane 304 may include one or more protrusions 312 extending from an edge of membrane 304 to form regions 314 between protrusions 312 (not comprising any membrane material). In some examples, membrane 304 may include a uniform perimeter (eg, formed into a circle) so as not to include any protrusions 312 (and may include more than one hole 310).

In some examples, the first top layer 302-1 may be directly adhered to the second top layer 302-2 with the adhesive 306 configured in a pattern such that the adhesive 306 is configured to align with the holes 310 (or holes 910 ) and/or any region 314 that does not include the film 304 is aligned. In this way, as best shown in FIG. 4A , the first top ply layer 302-1 can be adhered (via adhesive 306) to the second top ply layer 302-2 without adhering the membrane 304 to the first top ply layer 302-2. 1 and the second top layer 302-2 (while still embedding the membrane 304 between the first top layer 302-1 and the second top layer 302-2). In some examples, the film 304 may be adhered (via any suitable adhesive 306) to one or more of the first top ply 302-1 and the second top ply 302-2. Adhesive 306 may comprise any adhesive material having suitable properties for a given application of MEMS package 500 . In a non-limiting example, the adhesive 306 may include an epoxy.

In some examples, each of the first top deck layer 302-1 and the second top deck layer 302-2 may include one or more respective apertures 308-1 and 308-2 extending therethrough (i.e., one or more aperture). Aperture(s) 308-1 and aperture(s) 308-2 (i.e., one or more apertures) may be configured in a same pattern such that aperture(s) 308-1 and aperture(s) 308-2 are configured to be aligned (best as shown in Figures 4A and 4B). In some examples, hole(s) 308-1, 308-2 may form one or more acoustic ports to expose MEMS device 508 (FIG. 6) in cavity 408 to an external (ambient) environment.

As shown in Figures 4A and 4B, the membrane 304 can be configured to be in contact with each of the first top layer 302-1 and the second top layer 302-2. The membrane 304 can be configured to cover the holes 308-1, 308-2 in the respective top plate layers 302-1, 302-2. In some examples, the holes 308-1, 308-2 in the respective top plate layers 302-1, 302-2 can be configured to allow ambient pressure to reach the MEMS device 508, such as a pressure sensor (also referred to herein as referred to as a transducer)), while the membrane 304 can act as a filter to protect the MEMS device 50 from water (e.g., providing waterproofing), other liquids, and contamination (e.g., according to a desired ingress protection level (IPXX)) .

It should be understood that the size of the holes 308-1, 308-2 in the top deck layers 302-1, 302-2, the shape of the holes and the number of holes may vary depending on the desired airflow area. It should also be understood that the properties of the membrane 304, the density of the membrane 304, and/or the permeability of the membrane 304 may vary depending on a desired shielding level (eg, which may depend on a transducer application). In some examples, the first top layer 302 - 1 and the second top layer 303 - 2 can be configured to fully support the membrane 304 , limiting deflection of the membrane 304 .

In some examples, cover 200 (eg, body portion 202 and/or top plate layers 302-1, 302-2) may be formed from a conductive material including a metal. In some examples, the metal may include, but is not limited to, one or more of stainless steel, brass-plated, aluminum-plated, and nickel. In some examples, cover 200 (eg, body portion 202 and/or top plate layers 302-1, 302-2) may be formed from a polymer. In general, the material of cover 200 may comprise one material, or may comprise any combination of materials having suitable properties for protecting MEMS device 508, such as a pressure sensor. In some examples, the top plate portion 204 and the main body portion 202 of the cover 200 may be formed of the same material. In some examples, the top plate portion 204 and the main body portion 202 of the cover 200 may be formed of different materials.

Referring next to FIGS. 5 and 6 , a MEMS package 500 with a lid 200 is shown. In an example embodiment, the MEMS package 500 may include a base substrate 502, at least one integrated circuit 506 (eg, an application specific integrated circuit (ASIC)) disposed on the base substrate 502, disposed on and connected to MEMS device 508 (eg, MEMS pressure sensor) of integrated circuit 506 and lid 200 coupled to base substrate 502 (eg, via base portion region 406 ). MEMS package 500 may further include one or more connectors, wire bonds, bond pads, and the like. MEMS package 500 may also further include one or more additional layers 504 (e.g., one or more interconnection layers), which may be configured to direct electrical connection(s) to one or more structures on base substrate 502 , such as through one or more vias 510 . Lid 200 can be configured to cover MEMS device 508 (such that MEMS device 508 is encapsulated within cavity 408 ) and provide waterproofing and contamination protection for MEMS device 508 .

As discussed above, MEMS device 508 may comprise any device and/or sensor type that may be desired to be protected from fluids and/or contamination, including in applications where it is desired to expose MEMS device 508 to an external environment. In a non-limiting example, MEMS device 508 may include a MEMS pressure sensor.

MEMS package 500 (and MEMS package 700 shown in FIG. 7A ) may be used as part of any device useful for MEMS device 508, such as a pressure sensor, including environments that may be exposed to fluids and/or contamination. Non-limiting examples of devices that may include at least one MEMS package 500 include one or more of a wearable device, a mobile phone, an electronic notebook, a laptop, a computer, and the like.

Reference is next made to FIGS. 7A-8A . According to another aspect of the invention, an example MEMS package 700 is shown having a lid 702 . In particular, FIG. 7A is a cutaway perspective view of MEMS package 700; FIG. 7B is a detail view of portion 7B showing details of a portion of cover 702; FIG. A cross-sectional perspective view of cover 702.

Similar to MEMS package 500, MEMS package 700 may include a base substrate 716, at least one integrated circuit 506 (eg, an ASIC) disposed on base substrate 716, an integrated circuit(s) disposed on and connected to integrated circuit(s) 506. MEMS device 508 , such as a MEMS pressure sensor, and lid 702 coupled to base substrate 716 . MEMS package 700 also further includes one or more connectors, wire bonds, bond pads, and the like. Although not shown, MEMS package 700 may further include one or more additional layers (similar to layer(s) 504 ). Cover 702 can be configured to cover MEMS device 508 (such that MEMS device 508 is enclosed within cavity 714 ) and provide protection from water and contamination for MEMS device 508 .

Cover 702 is similar to cover 200 in that cover 702 may include a main body portion 802 and a top plate portion 804 (best shown in FIG. 8B ). Cover 702 differs from cover 200 in that cover 702 may be formed from a single piece of material 704 as a single monolithic component such that body portion 802 and top plate portion 804 are a unitary structure.

For example, as best shown in FIG. 7B , the top panel portion 804 may comprise a top panel layer 706 (integrated with the lid body portion 802 ) with the membrane 708 attached below the top panel layer 706 (e.g., adhered to the top panel layer via adhesive 710 706). In general, membrane 708 can be adhered to top plate layer 706 via adhesive 710 in such a way that membrane 708 can be configured to substantially block one or more liquids and contamination from entering cavity 714 . Membrane 708 is similar to membrane 304 in that membrane 708 is formed from a filter fabric, and in some embodiments the filter fabric may comprise any suitable ePTFE material. Adhesive 710 is similar to adhesive 306 . In some examples, at least one of a hydrophobic coating and an oleophobic coating may be disposed on the filter fabric forming membrane 708 . Although FIG. 7B appears to depict a gap between the film 708 and the top layer 706 , this only shows the area of the adhesive 710 between the film 708 and the top layer 706 . In fact, film 708 may be disposed on top layer 706 and coupled to top layer 706 via adhesive 710 .

In some embodiments, the top plate layer 706 may include one or more holes 712 (ie, one or more apertures) extending therethrough. Membrane 708 may be configured to cover hole(s) 712 . Aperture(s) 712 are similar to apertures 308-1, 308-2. In some examples, hole(s) 712 may form one or more acoustic ports to expose MEMS device 508 in cavity 714 to an external (ambient) environment. Similar to hole(s) 308-1, 308-2, the shape of hole(s) 712 and the number of hole(s) 712 may vary according to the desired air flow area. It should also be understood that, similar to membrane 304, the properties of membrane 708, the density of membrane 708, and/or the permeability of membrane 708 may vary according to a desired level of protection (e.g., it may depend on a transducer application) . In some examples, adhesive 710 may be applied between membrane 708 and top plate layer 706 in a manner that provides a seal around each hole 712 to substantially block fluid and/or contamination from entering cavity 714 through hole(s) 712 .

In some examples, monolithic material 704 may be formed from a conductive material including a metal. In some examples, the metal may include, but is not limited to, one or more of stainless steel, brass-plated, aluminum-plated, and nickel. In general, material 704 of cover 702 may comprise one material, or may comprise any combination of materials having suitable properties for protecting MEMS device 508, such as a pressure sensor.

Although FIGS. 7A-8B depict the cover 702 formed from a single piece of material 704, in some examples, the top plate portion 804 can be a separate component of the main body portion 802, and the top plate portion 804 can be coupled to the main body portion 802 (e.g., Press into the body of the cover). In some examples, the top plate portion 804 and the main body portion 802 of the cover 702 (of a separate component) may be formed from one and the same material. In some examples, the top plate portion 804 and the main body portion 802 of the cover (of a separate component) 702 may be formed of different materials.

Referring next to FIGS. 9A-10E , an example procedure is shown for fabricating one or more covers 918 of one or more housing packages, such as MEMS package 500 , wherein each housing package Configured to package a MEMS device (eg, MEMS device 508). Specifically. 9A-9F are perspective views illustrating an example process; and FIGS. 10A-10E are top views illustrating an example process.

Referring to FIGS. 9A and 10A , in a first step, a first (eg, bottom) top sheet 902-1 can be formed to have a first plurality of hole sets 904-1 arranged in a first pattern . In the first top sheet 902-1, each first hole set 904-1 is associated with a first top assembly 914-1 such that the first top sheet 902-1 comprises a plurality (i.e., a matrix) of first Top plate assembly (for multiple covers). Although each first hole set 904-1 is depicted as including a plurality of holes, in general, the first hole set 904-1 may include one or more holes. The first top sheet 902-1 may be formed from a metal material. In some examples, the metal material may include, but is not limited to, one or more of stainless steel, brass plating, aluminum plating, and nickel.

Referring to Figures 9B and 10B, in a second step, glue 906 (or more generally any suitable adhesive) can be placed on the first top sheet in a predetermined glue pattern (eg, by glue printing) 902-1 on.

Referring to FIGS. 9C and 10C , in a third step, the film sheet 908 may be disposed on the first top sheet 902 - 1 (eg, via roll lamination). In some examples, the membrane sheet 908 can be pre-cut during a stamping step (not shown), such that the membrane sheet 908 can include a second plurality of hole sets 910 having a second pattern. The membrane sheet 908 may be placed on the first top sheet 902-1 such that the adhesive pattern 906 (also shown in FIGS. ) alignment, so that the adhesive pattern 906 is exposed through the second hole set 910 of the film sheet 908. 9C and 10C also illustrate the location of the first hole set 904-1 associated with each first top plate assembly 914-1. Membrane sheet 908 may be formed from a filter fabric and may be configured to substantially block the passage of one or more liquids and contaminants. In some embodiments, the filter fabric may comprise any suitable ePTFE material. In some examples, at least one of a hydrophobic coating and an oleophobic coating may be disposed on at least a portion of the membrane sheet 908 .

Referring to FIGS. 9D and 10D , in a fourth step, a second (eg, top) top sheet 902-2 is patterned with a third plurality of hole sets 904-2 and disposed on a membrane sheet 908 (eg via tape lamination). The third hole set 904-2 has a third pattern corresponding to and aligned with the first pattern of the first hole set 904-1. In the second top sheet 902-2, each third hole set 904-2 is associated with a second top assembly 914-2 such that the second top sheet 902-2 comprises a plurality (i.e., a matrix) of second Top plate assembly (for multiple covers).

By placing the second top sheet 902-2 on the film sheet 908, the adhesive pattern 906 (exposed through the second hole set 910 of the film sheet 908) contacts the second top sheet 902-2, thereby placing the The second top sheet 902-2 is adhered to the first top sheet 902-1 (via the adhesive pattern 906), and the film sheet 908 is embedded in the first top sheet 902-1 and the second top sheet 902 -2 between to form a combined roof sheet. In this manner, the first hole set 904-1 and the third hole set 904-2 (of the respective first top sheet 902-1 and first top sheet 902-2) are covered by the membrane sheet 908, thereby providing a combined Waterproof and pollution protection of roof sheet. The second top sheet 902-2 may be formed from a metallic material. In some examples, the metal material may include, but is not limited to, one or more of stainless steel, brass plating, aluminum plating, and nickel.

9E and FIG. 10E, in a fifth step, strip punching (strip punching) can be applied to the combined roof sheet (formed in the fourth step) to form a number of trays, where each tray represents a cover 918 Top plate portion 912 (FIG. 9F). The roof portion 912 includes a portion of the membrane sheet 908 embedded between the first roof assembly 914-1 and the second roof assembly 914-2. The top plate portion 912 also includes a first hole set 904-1 in the first top plate assembly 914-1 (as shown in FIG. 9F ) and a third hole set 904-2 in the second top plate assembly 914-2, wherein the diaphragm A portion of the material covers the first and third hole sets 904-1, 904-2. In this manner, top plate portion 912 allows a MEMS device to be exposed to an external environment while substantially blocking fluid and/or contamination from entering an interior of cover 918 .

Referring to FIG. 9F , in a sixth step, top plate portion 912 (formed at the fifth step) may be coupled to body portion 916 to form lid 918 for a MEMS package such as MEMS package 500 . In some examples, top plate portion 912 may be press fit to body portion 916 . In some examples, body portion 916 and/or top plate portion 912 may be heated before and/or during the press-fit process. In some examples, a conductive adhesive, such as a conductive epoxy, may be used instead of or as part of the press-fit process.

The main body portion 916 may be formed of a metal material. In some examples, the metal material may include, but is not limited to, one or more of stainless steel, brass plating, aluminum plating, and nickel. In some examples, the top plate portion 912 and the main body portion 916 of the cover 918 may be formed from the same material. In some examples, the top plate portion 912 and the main body portion 916 of the cover 918 may be formed of different materials.

In some embodiments. The procedure shown in FIGS. 9A-10E may represent an example procedure for embedding an ePTFE filter in metal cap 918 .

While the invention has been discussed in terms of certain embodiments, it should be construed that the invention is not limited thereto. Embodiments are explained herein by way of example, but several modifications, variations and other embodiments can be employed which still remain within the scope of the invention.

100: MEMS sensor package 102: MEMS sensor 104: base substrate 106: cover 108: viscose 200: cover 202: main part 204: top plate part 302-1: First top layer 302-2: Second top layer 304: Membrane 306: Adhesive 308-1: hole 308-2: hole 310: hole 312: protrusion 314: area 402: side wall area 404: top section area 406: Base area 408: cavity 500: MEMS packaging 502: base substrate 504: extra layer 506: Integrated circuits 508:MEMS devices 510: through hole 700: MEMS packaging 702: cover 704: top layer 706: top layer 708: Membrane 710: Adhesive 712: hole 714: cavity 716: base substrate 802: main part 804: top plate part 902-1: First top sheet 902-2: Second top sheet 904-1: The first hole group 904-2: The third hole group 906:Viscose pattern 908: Membrane sheet 910: Hole/Second Hole Group 912: top plate part 914-1: First Top Plate Assembly 914-2: Second Top Plate Assembly 916: main part 918: cover

An example of a MEMS device package (referred to herein as a MEMS package) and one method of forming a MEMS package is shown in the accompanying drawings.

FIG. 1 is a cross-sectional view of a prior art MEMS sensor package.

2 is a perspective view of an example cover of a MEMS package according to an aspect of the present invention.

Fig. 3 is an exploded perspective view of the example cover shown in Fig. 2 according to an aspect of the present invention.

4A is a cross-sectional view of the lid shown in FIG. 2 according to an aspect of the invention.

4B is a cross-sectional perspective view of the lid shown in FIG. 2 according to an aspect of the invention.

5 is a perspective view of an example MEMS package in accordance with an aspect of the present invention.

6 is a cross-sectional perspective view of the MEMS package shown in FIG. 5 according to an aspect of the present invention.

7A is a cutaway perspective view of an example MEMS package according to another aspect of the present invention.

Figure 7B is a detail view of a portion 7B of Figure 7A according to an aspect of the present invention.

8A is a perspective view of the cover shown in FIG. 7 according to an aspect of the present invention.

8B is a cross-sectional perspective view of the lid shown in FIG. 8A according to an aspect of the present invention.

9A, 9B, 9C, 9D, 9E, and 9F are perspective views illustrating an example procedure for fabricating one or more lids of one or more MEMS packages in accordance with an aspect of the present invention .

10A, 10B, 10C, 10D, and 10E are top views illustrating an example procedure for fabricating one or more lids of one or more MEMS packages in accordance with an aspect of the present invention.

200: cover

202: main part

204: top plate part

Claims (30)

A microelectromechanical system (MEMS) package comprising: at least one MEMS device disposed on a base substrate; and a cover disposed on the base substrate, the cover configured to enclose the at least one MEMS device, The cover includes: a body portion configured to be coupled to the base substrate, a top plate portion, the body portion and the top plate portion forming a cavity in which the at least one MEMS device is enclosed, and A membrane configured to contact the top plate portion, the membrane formed from a filter fabric, the membrane configured to substantially block one or more liquids and contamination from entering the cavity. The MEMS package of claim 1, wherein the top plate portion includes a top plate layer, and the film is configured to be adhered to the top plate layer. The MEMS package of claim 1, wherein the top plate portion includes first and second top plate layers, the membrane is configured to be embedded between the first and second top plate layers, the top plate portion is configured to be coupled to the main body. The MEMS package according to claim 1, wherein the body portion and the top plate portion are formed as a monolithic structure. The MEMS package according to claim 1, further comprising at least one of a hydrophobic coating and an oleophobic coating disposed on the filter fabric. The MEMS package of claim 1, wherein the top plate portion includes one or more holes. The MEMS package of claim 6, wherein the membrane is configured to cover the one or more holes of the top plate portion. The MEMS package of claim 1, wherein the filter fabric comprises an expanded polytetrafluoroethylene (ePTFE) material. The MEMS package of claim 1, wherein the cover is formed of a conductive material including a metal. As the MEMS package of claim 9, wherein the metal includes one or more of stainless steel, brass plating, aluminum plating and nickel. The MEMS package of claim 1, wherein the at least one MEMS device includes at least one MEMS pressure sensor. The MEMS package of claim 1, wherein the film is configured to provide at least one of waterproofing and contamination protection for the at least one MEMS device. The MEMS package of claim 1, wherein the body portion includes an annular ring, and the top plate portion includes a disk. A method of manufacturing a microelectromechanical system (MEMS) package, the method comprising: forming a cover comprising a main body portion and a top plate portion such that the main body portion and the top plate portion form a cavity in which at least one MEMS device is configured to be enclosed; forming a membrane from a filter fabric; disposing the membrane on the roof portion such that the membrane is in contact with the roof portion, the membrane configured to substantially block one or more liquids and contamination from entering the cavity; and The cover is positioned on a base substrate such that a body portion of the cover is coupled to the base substrate, the base substrate including the at least one MEMS device disposed thereon. The method of claim 14, wherein forming the cover further comprises: forming the body portion and the top plate portion as a monolithic structure; and The membrane is adhered to the top plate portion. The method of claim 14, wherein forming the cover further comprises: providing first and second roof layers forming the roof portion; and coupling the top plate portion to the body portion, Wherein disposing the membrane further comprises embedding the membrane between the first top ply and the second top ply. The method of claim 16, wherein the first and second top ply are adhered together without adhering the film to the first and second top ply. The method of claim 16, wherein the film is adhered to one or more of the first and the second top sheet layers. As the method of claim 14, the method further includes: At least one of a hydrophobic coating and an oleophobic coating is disposed on the filter fabric. As the method of claim 14, the method further includes: One or more holes are formed in the top plate portion, wherein the membrane is configured to cover the one or more holes of the top plate. The method of claim 14, wherein the filter fabric comprises an expanded polytetrafluoroethylene (ePTFE) material. The method of claim 14, wherein the cover is formed of a material comprising one or more of a metal and a polymer. The method of claim 22, wherein the metal includes one or more of stainless steel, brass plating, aluminum plating and nickel. A method of manufacturing a plurality of housing packages, each housing package configured to enclose a microelectromechanical system (MEMS) device, the method comprising: providing a first roof layer having a substrate of first roof components, each of the first roof components having one or more first holes configured in a first pattern; providing a second roof layer having a matrix of second roof components, each of the second roof components having one or more second holes configured in a first pattern; providing a membrane layer comprising a filter fabric; embedding the film layer between the first roof layer and the second roof layer such that the substrate of the first roof component is aligned with the substrate of the second roof component to form a third roof layer; separating the third top plate layer to form a plurality of top plate portions corresponding to the plurality of housing packages; and The plurality of top plate portions are coupled to the plurality of base portions to form the plurality of housing packages. The method of claim 24, wherein the embedding of the film further comprises: The film layer is adhered to each of the first top ply and the second top ply. The method of claim 24, wherein the embedding of the film further comprises: forming one or more third holes configured in a second pattern in the film, the second pattern being different from the first pattern; disposing adhesive on one of the first top ply and the second top ply according to the second pattern; and The first top ply is adhered to the second top ply via the one or more third holes of the membrane according to the adhesive. The method of claim 24, wherein the filter fabric comprises an expanded polytetrafluoroethylene (ePTFE) material. The method of claim 24, wherein each of the first top layer, the second layer, and the plurality of base portions is formed of one or more metal materials including stainless steel, brass plating, aluminum plating, and nickel. As the method of claim 24, the method further includes: At least one of a hydrophobic coating and an oleophobic coating is disposed on at least a portion of the filter fabric. The method of claim 24, wherein the film layer is configured to substantially block one or more liquids and contamination from entering each of the plurality of housing packages.

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