Micro electro mechanical sensor packaging shell and installation method thereof

Abstract

The invention discloses a micro-electro-mechanical sensor packaging shell and an installation method thereof, the micro-electro-mechanical sensor packaging shell comprises a frame plate, the top of the frame plate is connected with a cover plate, the top of the cover plate is provided with a hole, the micro-electro-mechanical sensor packaging shell further comprises a plurality of salient points arranged at the bottom of the side wall of the frame plate, and folded edges located at the bottom of the side wall of the frame plate. When the shell is installed, preliminary positioning of the shell can be achieved through the metal slurry on the protruding points, after the shell is installed, due to the fact that the adhesive layer is formed in the whole gap, microbubbles in the gap are completely eradicated, the sealing performance is greatly improved, the protruding points at the bottom of the frame body can be wrapped by the adhesive layer, and the sealing performance is greatly improved. Therefore, the contact area between the metal slurry and the bottom of the frame body is increased, the frame body is more firmly bonded on the substrate, meanwhile, due to the existence of the salient points, the salient points can be blocked by the adhesive layer when moving in the adhesive layer, the frame body cannot directly move on the top of the adhesive layer, the shell cannot be loosened during use, and the service life of the shell is prolonged. And the use environment of the micro-electro-mechanical sensor is not influenced.

Description

Technical Field

[0001] The present invention specifically relates to a micro-electromechanical sensor packaging housing and a mounting method thereof. Background Art

[0002] MEMS sensors have broad application prospects and huge market potential due to their advantages of small size, light weight, low power consumption, low wafer-level mass production cost, and integration. Their application fields include wearable electronic devices, medical treatment, new energy vehicles, industry, aerospace, etc. When using, MEMS sensors usually need to be installed on the corresponding substrate and fixed with a metal cover. In order to ensure that the metal cover is tightly bonded to the conductive or thermal conductive metal paste on the substrate, its bottom structure is usually set to a flat surface, which can avoid water vapor infiltration in a humid environment and acid and alkali corrosion of chips, sensitive units or signal circuits in special environments. Before the metal cover is attached, the staff will apply the conductive or thermal conductive metal paste to the corresponding position of the substrate, and then fit the metal cover for the installation and use of the MEMS sensor; However, due to the long operating cycle of MEMS sensors, the metal slurry after coating is easily affected by the ambient temperature and humidity, and microbubbles are easily generated on the bonding surface between the metal cover and the substrate, causing the metal cover to loosen and the sealing to be poor, affecting the use of the MEMS sensor.

[0003] Therefore, it is necessary to invent a micro-electromechanical sensor packaging housing and an installation method thereof to solve the above problems. Summary of the invention

[0004] 1. Purpose of the invention The purpose of the present invention is to provide a micro-electromechanical sensor packaging shell and an installation method thereof. When installing the shell, the preliminary positioning of the shell can be achieved through the metal slurry on the convex points. After the shell is installed, a layer of adhesive layer is formed inside the entire gap, which prevents the generation of microbubbles in the gap and greatly improves the sealing performance. The adhesive layer will wrap the convex points at the bottom of the frame, thereby increasing the contact area between the metal slurry and the bottom of the frame, making the frame more firmly bonded to the substrate. At the same time, due to the presence of the convex points, the convex points will be blocked by the adhesive layer when moving inside the adhesive layer, so that the frame cannot move directly on the top of the adhesive layer, and the shell will not loosen during use, ensuring that the use environment of the micro-electromechanical sensor is not affected, so as to solve the above-mentioned shortcomings in the technology.

[0005] (II) Technical solution In order to achieve the above-mentioned purpose, the present invention provides the following technical solution: a micro-electromechanical sensor packaging shell, including a frame plate, a cover plate connected to the top of the frame plate, a hole opened on the top of the cover plate, and also including a plurality of protrusions arranged at the bottom of the side wall of the frame plate, and a folded edge located at the bottom of the side wall of the frame plate.

[0006] Preferably, the tops of the four sides of the cover plate are chamfered, and the corners of the four sides of the frame plate are chamfered.

[0007] Preferably, the thickness of the cover plate is set to 0.3 mm, and the height between the bottom and the top of the frame plate side wall is set to 0.8 mm.

[0008] Preferably, at least two protrusions are provided at the bottom of each side wall of the frame plate, the inner wall of the protrusion is flush with the inner wall of the side wall, and the protrusion is made of metal material.

[0009] Preferably, the length of the protrusion is set to 100 μm, the width is set to 100 μm, and the height is set to 15-30 μm.

[0010] A method for installing a micro-electromechanical sensor packaging housing comprises the following steps: S1. Select a container with a flat-bottomed groove and a heating coil installed at the bottom, and evenly apply the metal slurry into the groove so that the heating coil heats the metal slurry in the groove to reduce the viscosity of the metal slurry; S2, placing the housing above the container, ensuring that the protrusions are in contact with the metal slurry inside the groove, and the folded edge is mounted on the edge of the top opening of the groove to prevent the metal slurry from sticking to the bottom of the frame; S3, after the bumps are dipped in the metal slurry, the housing is taken out and temporarily attached to the to-be-attached portion of the substrate to temporarily protect the covered MEMS sensor; S4. Use a jet dispensing valve to spray metal slurry along the bottom of any three side walls of the frame plate. After standing for a while, the metal slurry will automatically flow along the bottom of the side wall of the frame plate due to capillary phenomenon, and then automatically fill the bottom of the entire frame plate. S5. Observe whether the bottom of the side wall that has not been sprayed with metal slurry is freely filled with metal slurry. If not, use the jet dispensing valve to spray metal slurry to replenish it. If it is filled, directly move the substrate with the shell attached to it into a vacuum pressure oven to degas and solidify the metal slurry due to baking.

[0011] Preferably, in step S1, the depth of the groove is 75-85% of the height of the bump, and the operating temperature of the heating coil is 50-100°C.

[0012] Preferably, in step S4 and step S5, the spraying inclination angle of the jet dispensing valve is 45 degrees.

[0013] Compared with the prior art, the above technical solution of the present invention has the following beneficial effects: The present invention arranges a plurality of protrusions at the bottom of the frame plate. When the shell is installed, the metal slurry on the protrusions can realize the preliminary positioning of the shell. After the shell is installed, an adhesive layer is formed inside the entire gap, which prevents the generation of microbubbles in the gap and greatly improves the sealing performance. The adhesive layer wraps the protrusions at the bottom of the frame to increase the contact area between the metal slurry and the bottom of the frame, making the frame more firmly bonded to the substrate. At the same time, due to the existence of the protrusions, that is, the protrusions need to overcome the resistance of the adhesive layer and cannot move easily, so that the frame cannot move directly on the top of the adhesive layer, so that the shell will not loosen during use, ensuring that the use environment of the micro-electromechanical sensor is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 A perspective view of the present invention; Figure 3 It is a schematic diagram of the bump of the present invention being dipped into the metal slurry in the container; Figure 4 It is a cross-sectional view of the bump of the present invention being dipped into metal slurry in a container; Figure 5 This is a demonstration diagram of the installation of the housing and the substrate of the present invention.

[0016] Description of reference numerals: 1 frame plate, 2 cover plates, 3 holes, 4 bumps, 5 folded edges. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0018] The present invention provides Figure 1-5 A micro-electromechanical sensor packaging shell shown includes a frame plate 1, a cover plate 2 connected to the top of the frame plate 1, a hole 3 is opened on the top of the cover plate 2, and also includes a plurality of protrusions 4 arranged at the bottom of the side wall of the frame plate 1, and a folded edge 5 located at the bottom of the side wall of the frame plate 1.

[0019] In one embodiment, the tops of the four sides of the cover plate 2 are chamfered, and the corners of the four sides of the frame plate 1 are chamfered, so that the corners of the side walls of the frame plate 1 are smooth and have no edges, which reduces stress concentration and has a certain aesthetics. The thickness of the cover plate 2 is set to 0.3mm, and the height between the bottom and the top of the side wall of the frame plate 1 is set to 0.8mm, which is suitable for the micro-electromechanical sensor on the substrate and can provide better protection for the micro-electromechanical sensor.

[0020] In one embodiment, at least two protrusions 4 are provided at the bottom of each side wall of the frame plate 1 to balance the force on the bottom of the frame plate 1 so that the frame plate 1 can remain horizontal after bonding. The inner wall of the protrusion 4 is flush with the inner wall of the side wall. The length of the protrusion 4 is set to 100 μm, the width is set to 100 μm, and the height is set to 15-30 μm, so that the frame plate 1 is more firmly bonded to the metal slurry.

[0021] A method for installing a micro-electromechanical sensor packaging housing comprises the following steps: S1, select a container with a flat-bottomed groove, the depth of which is 75-85% of the height of the bump 4, and a heating coil installed at the bottom, and the working temperature of the heating coil is 50-100°C, and evenly apply the metal slurry to the groove, so that the heating coil heats the metal slurry in the groove to reduce the viscosity of the metal slurry; S2, placing the housing above the container, ensuring that the protrusions 4 are in contact with the metal slurry inside the groove, and the folded edge 5 is mounted on the edge of the top opening of the groove to prevent the metal slurry from sticking to the bottom of the frame; S3, after the bumps 4 are dipped in the metal slurry, the housing is taken out and temporarily attached to the to-be-attached portion of the substrate to temporarily protect the covered micro-electromechanical sensor; S4, spray the metal slurry along the bottom of any three side walls of the frame plate 1 using a jet dispensing valve at a spraying angle of 45 degrees. After standing for a period of time, the metal slurry will automatically flow along the bottom of the side wall of the frame plate 1 due to capillary phenomenon, and then automatically fill the bottom of the entire frame plate 1; S5. Observe whether the bottom of the side wall that has not been sprayed with metal slurry is freely filled with metal slurry. If not, use the jet dispensing valve to spray metal slurry to replenish it. If it is filled, directly move the substrate with the shell attached to it into a vacuum pressure oven to degas and solidify the metal slurry due to baking.

[0022] Implementation method: Figure 3-5 As shown, reference numeral 6 is a container, 7 is a groove, 8 is a heating coil, 9 is a substrate, and 10 is a micro-electromechanical sensor; During installation, the present invention pours metal slurry into a container with grooves and heats it to raise the temperature of the metal slurry, and then places the shell on the top of the container. At this time, since a plurality of convex points 4 are provided at the bottom of the frame plate 1, the bottom of the frame plate 1 will not directly contact the metal slurry, thus preventing a vacuum state from being formed between the frame plate 1 and the container, which may cause the shell to be unable to be peeled off. Then, when the shell is transferred to the substrate, since the convex point 4 is dipped with metal slurry, the shell can be initially positioned on the substrate and will not move. At this time, the metal slurry is directly sprayed in the gap between the bottom of any three side walls of the frame plate 1 and the substrate using a jet dispensing valve, so that the metal slurry automatically flows and wanders inside the gap by the nature of its own wool phenomenon, and since the surface of the metal slurry and the surface of the frame are hydrophilic, the metal slurry will not flow out of the gap, thereby making the entire gap coated with metal slurry. If the metal slurry at the bottom of the side wall that has not been sprayed is still not filled, the jet dispensing valve is directly used to spray and supplement, so as to avoid the existence of unfilled holes in the gap and greatly reduce the use of metal slurry. Finally, the shell is finally positioned by moving the base with the shell attached into a vacuum pressure oven to degas and solidify the metal slurry due to baking; When the installed and fixed shell is in use, the entire gap is filled with metal slurry, that is, the metal slurry forms an adhesive layer in the gap, which prevents the generation of micro bubbles in the gap and greatly improves the sealing performance. The adhesive layer will wrap the convex point 4 at the bottom of the frame, thereby increasing the contact area between the metal slurry and the bottom of the frame, making the frame more firmly bonded to the substrate. At this time, due to the presence of the convex point 4, the convex point 4 will be blocked by the adhesive layer when moving inside the adhesive layer, that is, the convex point 4 needs to overcome the resistance of the adhesive layer and cannot move easily, so that the frame cannot move directly on the top of the adhesive layer, and further, the shell after the final positioning will not be loosened when in use, ensuring that the use environment of the micro-electromechanical sensor is not affected; Among them, capillary phenomenon, also known as capillary action or capillary effect, is a phenomenon in which a liquid flows in a narrow space without the need for external force, and sometimes even in the opposite direction of gravity. It is a common physical phenomenon, and hydrophilicity refers to the affinity of a substance for water, that is, the property that water molecules can be tightly bound to a substance through forces such as hydrogen bonds; This embodiment specifically solves the problem in the prior art that due to the long operation cycle of the MEMS sensor, the metal slurry after coating is easily affected by the ambient temperature and humidity, and microbubbles are easily generated on the fitting surface between the metal cover and the substrate, resulting in loosening of the metal cover and poor sealing, which affects the use of the MEMS sensor.

[0023] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A micro-electromechanical sensor packaging housing, characterized in that: It comprises a frame plate (1), the top of the frame plate (1) is connected to a cover plate (2), and the top of the cover plate (2) is provided with a hole (3); It also includes a plurality of protrusions (4) arranged at the bottom of the side wall of the frame plate (1), and a folded edge (5) located at the bottom of the side wall of the frame plate (1).

2. The micro-electromechanical sensor package housing according to claim 1, characterized in that: The tops of the four sides of the cover plate (2) are chamfered, and the corners of the four sides of the frame plate (1) are chamfered.

3. The micro-electromechanical sensor package housing according to claim 1, characterized in that: The thickness of the cover plate (2) is set to 0.3 mm, and the height between the bottom and the top of the side wall of the frame plate (1) is set to 0.8 mm.

4. The micro-electromechanical sensor package housing according to claim 1, characterized in that: At least two protrusions (4) are arranged at the bottom of each side wall of the frame plate (1); the inner wall of the protrusion (4) is flush with the inner wall of the side wall; and the protrusion (4) is made of metal material.

5. The micro-electromechanical sensor packaging housing according to claim 1, characterized in that: The length of the protrusion (4) is set to 100 μm, the width is set to 100 μm, and the height is set to 15-30 μm.

6. A method for installing a micro-electromechanical sensor package housing according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Select a container with a flat-bottomed groove and a heating coil installed at the bottom, and evenly apply the metal slurry into the groove so that the heating coil heats the metal slurry in the groove to reduce the viscosity of the metal slurry; S2, placing the housing above the container, ensuring that the protrusion (4) is in contact with the metal slurry inside the groove, and the folded edge (5) is mounted on the edge of the top opening of the groove to prevent the metal slurry from sticking to the bottom of the frame; S3, after the bumps (4) are dipped in the metal slurry, the shell is taken out and temporarily attached to the to-be-attached portion of the substrate to temporarily protect the covered micro-electromechanical sensor; S4. Use a spray dispensing valve to spray metal slurry along the bottom of any three side walls of the frame plate (1). After standing for a period of time, the metal slurry will automatically flow along the bottom of the side walls of the frame plate (1) due to capillary phenomenon, and then automatically fill the bottom of the entire frame plate (1); S5. Observe whether the bottom of the side wall that has not been sprayed with metal slurry is freely filled with metal slurry. If not, use the jet dispensing valve to spray metal slurry to replenish it. If it is filled, directly move the substrate with the shell attached to it into a vacuum pressure oven to degas and solidify the metal slurry due to baking.

7. The method for installing a micro-electromechanical sensor package housing according to claim 1, characterized in that: In step S1, the depth of the groove is 75-85% of the height of the protrusion (4), and the working temperature of the heating coil is 50-100°C.

8. The method for installing a micro-electromechanical sensor package housing according to claim 1, characterized in that: In step S4 and step S5, the spraying angle of the jet dispensing valve is 45 degrees.

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