Key assembly, hydrophobic diaphragm and method for manufacturing hydrophobic diaphragm

Abstract

The application discloses a key assembly, a hydrophobic diaphragm and a preparation method of the hydrophobic diaphragm. The key assembly comprises a key body and a hydrophobic diaphragm. The key body comprises at least a main body part. The main body part is located at a hollow part of a shell corresponding to a trigger area. The hydrophobic diaphragm is arranged at the periphery of the main body part and is used for limiting the flow of liquid falling thereon. By attaching the liquid binding diaphragm at the edge of the key, the flow of liquid falling on the key can be effectively prevented, and the liquid can be prevented from flowing into the electronic device below the key through the gap between the key and the shell. Compared with the method of arranging liquid-proof glue and dispensing glue at the gap to prevent the liquid from flowing into the electronic device, the key body provided by the application can be repeatedly disassembled and assembled without being scrapped.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic device related component design and manufacturing, in particular to a key assembly of an electronic device, a hydrophobic diaphragm and a preparation method of the hydrophobic diaphragm. BACKGROUND

[0002] Electronic devices need to have keys (power keys or keyboards, etc.) as switches for users to issue instructions to the electronic devices, and electronic devices such as circuit boards or flat cables are needed below the keys. However, there will inevitably be an assembly gap between the keys and the shell during assembly, and if the user accidentally drops liquid (such as water) on the keys, the liquid water will enter the electronic devices such as the circuit board along the gap, which can easily cause damage to the electronic devices. SUMMARY

[0003] In view of the above technical problems in the prior art, embodiments of the present application provide a key assembly, a hydrophobic diaphragm and a preparation method of the hydrophobic diaphragm.

[0004] To solve the above technical problems, the technical solution adopted by the embodiments of the present application is as follows:

[0005] A key assembly, comprising a key body and a hydrophobic diaphragm; the key body at least comprises a main body part, the main body part is located at a hollow part of a shell corresponding to a trigger area, the hydrophobic diaphragm is arranged on the periphery of the main body part, and the hydrophobic diaphragm is used to limit the flow of liquid dropped thereon.

[0006] Preferably, the key body further comprises an edge part located on the periphery of the main body part and integrated with the main body part, and the hydrophobic diaphragm is attached to the upper surface of the edge part.

[0007] Preferably, the main body part of the key body and the edge part of the key body form a stepped structure, and the main body part is higher than the edge part.

[0008] Preferably, the key assembly further comprises an elastic reset part, and the elastic reset part is arranged at the bottom of the main body part.

[0009] Preferably, the elastic reset part is made of foam.

[0010] Preferably, the elastic reset part is annular; wherein:

[0011] A trigger protrusion is formed in the center of the bottom of the main body part.

[0012] Preferably, a sink is formed on the periphery of the hollow part of the shell, and the edge part of the key body is lapped on the bottom of the sink.

[0013] Preferably, a hub is further arranged on the shell, and the hub is pressed against the edge part.

[0014] Preferably, the key body is made of elastic material.

[0015] The application also discloses a hydrophobic diaphragm, comprising a diaphragm body and hydrophobic units formed on at least one side of the diaphragm body, each of the hydrophobic units having a restricted area surrounded by a concave-convex structure which restricts liquid in the restricted area.

[0016] Preferably, the hydrophobic units are formed on both sides of the diaphragm body.

[0017] The application also discloses a preparation method of the hydrophobic diaphragm, comprising the following steps:

[0018] S10: laying a silicon wafer base layer;

[0019] S20: forming a SiO2 layer on the upper surface of the silicon wafer base layer;

[0020] S30: etching a concave-convex structure on the upper surface of the SiO2 layer;

[0021] S40: forming a Si3N4 layer on the upper surface of the SiO2 layer, so that the lower surface of the Si3N4 layer matches the SiO2 layer to form the concave-convex structure;

[0022] S50: etching a concave-convex structure on the upper surface of the Si3N4 layer;

[0023] S70: removing the SiO2 layer to separate the silicon wafer base layer from the Si3N4 layer, both surfaces of the Si3N4 layer forming the concave-convex structure, thereby preparing the hydrophobic diaphragm.

[0024] Preferably, step S30 comprises:

[0025] S31: coating positive photoresist on the upper surface of the SiO2 layer;

[0026] S32: carrying out interval exposure on the positive photoresist to remove material of the positive photoresist so that the positive photoresist forms a tooth groove structure;

[0027] S33: removing the positive photoresist in the groove of the tooth groove structure which has been exposed;

[0028] S34: carrying out dry etching on the upper surface of the SiO2 layer corresponding to the groove of the positive photoresist of the tooth groove structure;

[0029] S35: removing the positive photoresist which has not been exposed by using a removing liquid to expose the concave-convex structure on the upper surface of the SiO2 layer.

[0030] Preferably, step S50 comprises:

[0031] S51: planarizing the upper surface of the Si3N4 layer;

[0032] S52: coating the upper surface of the planarized Si3N4 layer with a positive photoresist;

[0033] S53: interval exposing the positive photoresist to remove material of the positive photoresist so as to form a tooth groove structure of the positive photoresist;

[0034] S54: removing the positive photoresist in the groove of the exposed tooth groove structure;

[0035] S55: dry etching the upper surface of the Si3N4 layer corresponding to the groove of the positive photoresist of the tooth groove structure;

[0036] S56: removing the unexposed positive photoresist by using a removing liquid so as to expose the upper surface of the Si3N4 layer to a concave-convex structure.

[0037] Preferably, the method for preparing the hydrophobic membrane sheet further comprises a step S60 of etching the side edges of the Si3N4 layer so as to make the side edges of the Si3N4 layer flush between the step S50 and the step S70.

[0038] Preferably, the step S60 comprises:

[0039] S61: coating the upper surface of the Si3N4 layer with a positive photoresist;

[0040] S62: exposing the positive photoresist corresponding to the side edges of the Si3N4 layer to cut off the positive photoresist corresponding to the side edges of the Si3N4 layer;

[0041] S63: removing the positive photoresist corresponding to the side edges of the Si3N4 layer which has been exposed;

[0042] S64: dry etching the side edges of the Si3N4 layer so as to make the side edges of the Si3N4 layer flush;

[0043] S65: removing the unexposed positive photoresist by using a removing liquid so as to re-expose the concave-convex structure of the upper surface of the Si3N4 layer.

[0044] Preferably, in the step S70, the SiO2 layer is removed by using a wet etching process so as to separate the Si3N4 layer from the silicon wafer base layer.

[0045] Compared with the prior art, the key assembly, the hydrophobic membrane sheet and the method for preparing the hydrophobic membrane sheet provided by the embodiments of the present application have the following beneficial effects:

[0046] 1. By attaching the liquid-repellent film at the edge of the key, the liquid flowing on the key can be effectively prevented, and the liquid flowing into the electronic device below the key through the gap between the key and the shell can be avoided; compared with the method of setting liquid-proof glue and dispensing glue at the gap to prevent the liquid from flowing into the electronic device, the key body provided by the application can be repeatedly disassembled without being scrapped.

[0047] 2. The hydrophobic film prepared by the method provided by the application has strong water-binding capacity. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The cross-sectional view of the key assembly provided by the embodiment of the application.

[0049] Figure 2 The enlarged view of part A of Figure 1

[0050] Figure 3 The microscopic view of the hydrophobic film in the key assembly provided by the embodiment of the application.

[0051] Figure 4 The exploded view of the key assembly provided by the embodiment of the application (mainly related to the assembly relationship of the key body and the hydrophobic film).

[0052] Figure 5 The assembly view of the key assembly provided by the embodiment of the application.

[0053] Figure 6 The process flow chart of the preparation method of the hydrophobic film provided by the embodiment of the application.

[0054] In the drawings:

[0055] 10-key body; 11-main body part; 12-edge part; 13-triggering protrusion; 20-hydrophobic film; 21-micro concave-convex structure; 30-double-sided adhesive; 40-elastic reset component; 50-hub; 100-shell; 101-sunken groove; 200-electronic device; 201-triggering area. DETAILED DESCRIPTION

[0056] In order for those skilled in the art to better understand the technical solutions of the application, the application will be described in detail below in combination with the drawings and specific embodiments.

[0057] The embodiment of the application discloses a key assembly, such as Figure 1 ​As shown, the key assembly is used to be installed on the electronic device for triggering the trigger area 201 (such as the trigger area 201 of the circuit board) of the electronic device 200 inside the shell 100 of the electronic device, and then sending control instructions to the electronic device, for example, controlling the electronic device to open and close. The electronic device can be a notebook computer, a tablet computer, and the key assembly can be a switch key of the electronic device.

[0058] A hollow part is formed on the shell 100 of the electronic device which needs to install the key, and the hollow part corresponds to the trigger area 201 (such as the trigger area 201 of the circuit board) of the electronic device 200 inside the shell 100. The key assembly provided by the application is installed in the hollow part.

[0059] As shown, Figures 1 to 5 The key assembly comprises a key body 10, a hydrophobic film 20, and an elastic reset component 40.

[0060] The key body 10 comprises a central main body part 11 and a peripheral edge part 12 formed on the main body part 11. When the key body 10 is in the installed state, the edge part 12 is closer to the gap between the key body 10 and the shell 100. The upper surface of the main body part 11 of the key body 10 is formed as an arc-shaped concave surface suitable for pressing.

[0061] The hydrophobic film 20 is attached to the edge part 12 of the key body 10. The hydrophobic film 20 has a binding effect on the liquid (mostly water) falling on it to prevent the liquid from flowing in the gap direction, thereby limiting the liquid from entering the electronic device 200 (such as the circuit board) inside the electronic device through the gap.

[0062] The microstructure of the hydrophobic film 20 is as follows:

[0063] As shown, Figure 3 A plurality of hydrophobic units are formed on the upper surface of the hydrophobic film 20. Each hydrophobic unit is composed of a plurality of nano-level micro-convex and concave structures 21. The convex and concave structures of each hydrophobic unit enclose a restricted area. When the liquid falls on the upper surface of the hydrophobic film 20, the liquid is bound in the restricted area by the micro-convex and concave structures 21 of the hydrophobic unit. From a macroscopic point of view, the hydrophobic film 20 has the ability to effectively prevent the liquid from flowing. In the actual manufacturing process, the micro-convex and concave structures 21 on the upper surface of the hydrophobic film 20 can be obtained by exposing and etching silicon-based materials and organic materials.

[0064] As shown, Figure 1As shown, the elastic reset component 40 is disposed between the button body 10 and the trigger area 201 of the electronic device 200 located below the button body 10. After the button body 10 is pressed, the elastic reset component 40 is used to reset the button body 10. The elastic reset component 40 can be a spring, a spring sheet, or elastic foam. Using elastic foam is more effective in protecting the button body 10 and the electronic device 200 (such as a circuit board) from damage.

[0065] In some preferred embodiments, the button body 10 is circular, such that the main body 11 of the button body 10 is circular, the edge 12 of the button body 10 is annular, and the shape of the hydrophobic film 20 is annular to adapt to the structure of the button body 10.

[0066] In some preferred embodiments, a stepped structure is formed between the main body 11 of the button body 10 and the edge 12 of the button body 10, and the edge 12 is lower than the main body 11, so that the edge 12 and the hydrophobic film 20 do not protrude from the housing 100, while the main body 11 can be flush with the surface of the housing 100.

[0067] like Figure 1 As shown, the hydrophobic film 20 can be attached to the button body 10 in various ways. In some preferred embodiments, the hydrophobic film 20 is attached to the edge 12 of the button body 10 by means of double-sided adhesive 30, which allows the hydrophobic film 20 to quickly form a whole with the button body 10.

[0068] In some preferred embodiments, the button body 10 may be made of an elastic material, so that the button body 10 has a tendency to reset after being released from pressure.

[0069] In some preferred embodiments, a columnar trigger protrusion 13 is formed at the center of the bottom of the button body 10, and an elastic reset member 40 is used to fit over the trigger protrusion 13. When the button body 10 is pressed, the trigger protrusion 13 is used to contact the trigger area 201 of the electronic device 200.

[0070] In some preferred embodiments, a recessed groove 101 is formed around the hollow portion of the housing 100. The edge portion 12 of the button body 10 is located at the bottom of the recessed groove 101. A hub 50 is also fastened in the area corresponding to the recessed groove 101, and the hub 50 positions the edge portion 12 of the button between the housing 100 and the hub 50. In this way, the edge portion 12 of the button body 10 and the hydrophobic film 20 are shielded by the hub 50, and only the upper surface of the main body portion 11 of the button body 10 is exposed outside the housing 100. This is beneficial to improving the appearance quality of the electronic device and to achieving better installation positioning of the button body 10.

[0071] The advantages of the button assembly provided by this invention are:

[0072] By attaching the hydrophobic film sheet 20 at the edge of the key, the liquid falling on the key can be effectively prevented from flowing, and the liquid can be prevented from flowing into the electronic device 200 located below the key through the gap between the key and the shell 100. Compared with the method of setting liquid-proof glue and dispensing glue at the gap to prevent the liquid from flowing into the electronic device 200, the key body 10 provided by the application can be repeatedly disassembled and assembled without being scrapped.

[0073] As shown in Figure 6 The embodiment of the application further discloses a preparation method of the hydrophobic film sheet 20, comprising the following steps:

[0074] S10: providing a silicon wafer base layer (or Si water layer).

[0075] S20: depositing a SiO2 layer on the upper surface of the silicon wafer base layer by using a PECVD (plasma enhanced chemical vapor deposition) film deposition machine, and the deposition thickness is greater than 0.5 μm, and preferably, the deposition thickness is 1.5 μm.

[0076] S30: etching a concave-convex structure on the upper surface of the SiO2 layer, and the concave-convex structure comprises the following steps:

[0077] S31: uniformly coating positive photoresist on the upper surface of the SiO2 layer by using a photoresist coating machine.

[0078] S32: performing interval exposure on the positive photoresist by using an exposure machine and a mask to remove the material of the positive photoresist and form a tooth groove structure.

[0079] S33: removing the positive photoresist in the groove of the tooth groove structure by using a developer.

[0080] S34: performing reactive ion etching (dry etching) on the upper surface of the SiO2 layer corresponding to the groove of the positive photoresist of the tooth groove structure, and the etching thickness is greater than 0.25 μm, and preferably, the etching thickness is 1 μm.

[0081] S35: removing the positive photoresist which is not exposed by using acetone, methanol and deionized water (as a removal liquid) to expose the concave-convex structure on the upper surface of the SiO2 layer.

[0082] S40: depositing a Si3N4 layer on the upper surface of the SiO2 layer by using a PECVD (plasma enhanced chemical vapor deposition) film deposition machine, so that the lower surface of the Si3N4 layer matches the concave-convex structure of the SiO2 layer, and the deposition thickness is greater than 1 μm, and preferably, the deposition thickness is 3 μm.

[0083] S50: etching a concave-convex structure on the upper surface of the Si3N4 layer, and the concave-convex structure comprises the following steps:

[0084] S51: The upper surface of the Si3N4 layer formed by deposition is planarized by a chemical mechanical polishing process (CMP), and the planarization thickness should be greater than 0.25 μm, preferably, the planarization thickness is 0.5 μm.

[0085] S52: The upper surface of the planarized Si3N4 layer is uniformly coated with a positive photoresist by using a photoresist coater.

[0086] S53: The positive photoresist is interval-exposed by using an exposure machine and a mask to remove the material of the positive photoresist so as to form a tooth groove structure.

[0087] S54: The positive photoresist in the groove of the tooth groove structure which has been exposed is removed by using a developer.

[0088] S55: The upper surface of the Si3N4 layer corresponding to the groove of the positive photoresist of the tooth groove structure is subjected to reactive ion etching (dry etching), and the etching thickness should be greater than 0.25 μm, preferably, the etching thickness is 1 μm.

[0089] S56: The unexposed positive photoresist is removed by using acetone, methanol and deionized water (as a removal liquid) so as to expose the upper surface of the Si3N4 layer to a concave-convex structure.

[0090] S60: The side edge of the Si3N4 layer is etched so as to make the side edge of the Si3N4 layer neat, which specifically comprises the following steps:

[0091] S61: The upper surface of the Si3N4 layer is uniformly coated with a positive photoresist by using a photoresist coater.

[0092] S62: The positive photoresist corresponding to the side edge of the Si3N4 layer is exposed by using an exposure machine and a mask so as to cut off the positive photoresist corresponding to the side edge of the Si3N4 layer.

[0093] S63: The positive photoresist corresponding to the side edge of the Si3N4 layer which has been exposed is removed by using a developer.

[0094] S64: The side edge of the Si3N4 layer is subjected to reactive ion etching (dry etching) so as to make the side edge of the Si3N4 layer neat and expose the SiO2 layer.

[0095] S65: The unexposed positive photoresist is removed by using acetone, methanol and deionized water (as a removal liquid) so as to re-expose the concave-convex structure of the upper surface of the Si3N4 layer.

[0096] S70: The SiO2 layer is removed by using a wet etching process so as to separate the Si3N4 layer from the silicon wafer base layer. Both surfaces of the Si3N4 layer form a concave-convex structure, thereby preparing a hydrophobic membrane sheet 20.

[0097] The hydrophobic membrane sheet 20 obtained by the above method has the following advantages: Figure 3The plurality of micro-convex structures 21 shown enclose hydrophobic units, and liquid is bound by the micro-convex structures 21 of the hydrophobic units.

[0098] The hydrophobic film 20 prepared by the above method is cut and fixed to the edge of the key by double-sided adhesive.

[0099] The hydrophobic film 20 can be made into a double-sided micro-convex structure by the above method, in which case, either side of the hydrophobic film 20 has a hydrophobic effect, and it is not necessary to distinguish between the hydrophobic side and the non-hydrophobic side when in use. Of course, the hydrophobic film 20 can also be made into a single-sided micro-convex structure, in which case, the hydrophobic side with the micro-convex structure is used as the surface, and the non-micro-convex structure side is bonded to the relevant component (for example, bonded to the surface of the key).

[0100] The method for preparing the hydrophobic film provided by the application has the following advantages:

[0101] The hydrophobic film prepared by the above method has a strong water binding capacity.

[0102] The above examples are merely exemplary embodiments of the application, and are not intended to limit the application, and the scope of protection of the application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the application within the spirit and scope of the application, and such modifications or equivalent replacements should also be considered to fall within the scope of protection of the application.

Claims

1. A method of making a hydrophobic membrane sheet, characterized by, The method comprises the following steps: S10: providing a silicon wafer base layer; S20: forming a SiO2 layer on the upper surface of the silicon wafer base layer; S30: etching a concave-convex structure on the upper surface of the SiO2 layer; S40: forming a Si3N4 layer on the upper surface of the SiO2 layer; S50: etching a concave-convex structure on the upper surface of the Si3N4 layer; S70: removing the SiO2 layer to separate the silicon wafer base layer from the Si3N4 layer, and the two surfaces of the Si3N4 layer are formed with the concave-convex structure, thereby preparing a hydrophobic film piece; Step S30 comprises: S31: applying a positive photoresist on the upper surface of the SiO2 layer; S32: performing interval exposure on the positive photoresist to remove the material of the positive photoresist so as to form a tooth groove structure; S33: removing the positive photoresist in the groove of the tooth groove structure which has been exposed; S34: performing dry etching on the upper surface of the SiO2 layer corresponding to the groove of the positive photoresist of the tooth groove structure; S35: removing the unexposed positive photoresist by using a removal liquid to expose the concave-convex structure on the upper surface of the SiO2 layer.

2. The method of claim 1, wherein the hydrophobic membrane is prepared by a method comprising: Step S50 comprises: S51: planarizing the upper surface of the Si3N4 layer; S52: applying a positive photoresist on the upper surface of the planarized Si3N4 layer; S53: performing interval exposure on the positive photoresist to remove the material of the positive photoresist so as to form a tooth groove structure; S54: removing the positive photoresist in the groove of the tooth groove structure which has been exposed; S55: performing dry etching on the upper surface of the Si3N4 layer corresponding to the groove of the positive photoresist of the tooth groove structure; S56: removing the unexposed positive photoresist by using a removal liquid to expose the concave-convex structure on the upper surface of the Si3N4 layer.

3. The method of claim 1, wherein the hydrophobic membrane is prepared by a method comprising: The method for preparing the hydrophobic film piece comprises the following steps between step S50 and step S70: Step S60: etching the side edges of the Si3N4 layer to make the side edges of the Si3N4 layer neat.

4. The method of claim 2, wherein the hydrophobic membrane is prepared by a method comprising: Step S60 comprises: S61: applying a positive photoresist on the upper surface of the Si3N4 layer; S62: exposing the positive photoresist corresponding to the side edges of the Si3N4 layer to cut off the positive photoresist corresponding to the side edges of the Si3N4 layer; S63: removing the positive photoresist corresponding to the side edges of the Si3N4 layer which has been exposed; S64: performing dry etching on the side edges of the Si3N4 layer to make the side edges of the Si3N4 layer neat; S65: removing the unexposed positive photoresist by using a removal liquid to re-expose the concave-convex structure on the upper surface of the Si3N4 layer.

5. The method of claim 1, wherein the hydrophobic membrane is prepared by a method comprising: In step S70, the SiO2 layer is removed by using a wet etching process to separate the silicon wafer base layer from the Si3N4 layer.

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