Silica gel key structure based on conductivity improvement

Abstract

The utility model discloses a silica gel button structure based on conductivity improvement, comprising a silica gel substrate, the bottom of the silica gel substrate is provided with a conductive layer and conductive particles embedded in the silica gel substrate, and the conductive layer comprises a base layer, an enhancement layer, conductive bumps and a protection layer. According to the silica gel key structure based on conductivity improvement, conductivity improvement is achieved by embedding the conductive particles into the silica gel substrate and arranging the base layer, the enhancement layer and the conductive salient points at the bottom, the service life of the conductive layer is prolonged through the protection layer, and the silica gel key structure has the effect of stable performance in the environment with the humidity of 90% or the temperature of-30-100 DEG C.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic equipment key technical field, concretely is the silica gel key structure based on conductivity promotion. BACKGROUND

[0002] The conductivity of traditional silica gel keys mainly depends on single-layer conductive coating (such as carbon paste or silver paste), and the following problems exist:

[0003] Conductive decay: the conductive layer is prone to wear or oxidation after long-term use, leading to increased contact resistance and unstable signal transmission.

[0004] Small contact area: the planar conductive layer does not fully contact the circuit board, and is prone to key failure due to slight deviation.

[0005] Poor resistance to environmental interference: humid and high-temperature environments accelerate the aging of the conductive layer. INVENTION CONTENTS

[0006] To overcome the deficiencies of the prior art, the utility model provides a silica gel key structure based on conductivity improvement, which solves the problems of conductive decay, small contact area and poor resistance to environmental interference.

[0007] To achieve the above purposes, the utility model realizes the following technical scheme: a silica gel key structure based on conductivity improvement, comprising a silica gel base body, a conductive layer and conductive particles embedded in the silica gel base body are arranged at the bottom of the silica gel base body.

[0008] The conductive layer comprises a base layer, the surface of the base layer is provided with a reinforcing layer, and the bottom of the base layer integrally extends a conductive bump, and the surfaces of the base layer, the reinforcing layer and the conductive bump are provided with a protective layer.

[0009] Preferably, the reinforcing layer is formed by interweaving silver nanowires and carbon fibers in a mass ratio of 3:1 to 5:1.

[0010] Preferably, the conductive bump is semispherical, and the height-to-diameter ratio is 1:1.5 to 1:2.5.

[0011] Preferably, the protective layer is made of fluorocarbon resin.

[0012] Preferably, the base layer is made of high-density silver-carbon composite material.

[0013] Preferably, the conductive particles are silver-plated copper powder with a particle size of 5 to 20 μm.

[0014] The utility model provides a silica gel key structure based on conductivity improvement. Compared with the prior art, the following beneficial effects are achieved:

[0015] The silicon rubber key structure based on the improvement of the conductivity is characterized by the following: the conductive particles are embedded in the silicon rubber base body, and the base layer, the reinforcing layer and the conductive bumps are arranged at the bottom to improve the conductivity, the protective layer prolongs the service life of the conductive layer, and the performance is stable under the environment of humidity of 90% or temperature of-30-100 DEG C. BRIEF DESCRIPTION OF DRAWINGS

[0016] Fig. 1 It is a structural schematic view of the utility model;

[0017] Fig. 2 It is a structural bottom view schematic view of the utility model;

[0018] Fig. 3 It is a structural split schematic view of the utility model.

[0019] In the drawing: 1, silicon rubber base body; 2, conductive layer; 21, base layer; 22, reinforcing layer; 23, conductive bump; 24, protective layer; 3, conductive particle. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0021] Please refer to Figs. 1-3 The utility model provides a technical scheme: the silicon rubber key structure based on the improvement of the conductivity, including the silicon rubber base body 1, the bottom of the silicon rubber base body 1 is provided with the conductive layer 2 and the conductive particle 3 embedded in the silicon rubber base body 1, the material of the conductive particle 3 is silver-plated copper powder, and the particle size is 5-20 μm, the silver-plated copper powder is uniformly dispersed in the silicon rubber base body 1, and the conductive path that penetrates the base body is formed, even if the surface layer is worn, the conductivity can still be maintained through the internal particles.

[0022] The conductive layer 2 includes the base layer 21, the reinforcing layer 22, the conductive bump 23 and the protective layer 24, the material of the base layer 21 is high-density silver-carbon composite material, is directly printed in the bottom of the silicon rubber key, provides initial low-resistance path.

[0023] The reinforcing layer 22 is interwoven by silver nanowire and carbon fiber with 3:1-5:1 mass ratio, is superimposed on the base layer 21, and a three-dimensional conductive network is formed by the interweaving of silver nanowire and carbon fiber, which enhances the current carrying capacity and inhibits crack propagation.

[0024] The conductive protrusions 23 are hemispherical, with a height to diameter ratio of 1:1.5~1:2.5, and the array of hemispherical conductive protrusions 23 at the bottom of the silica gel base 1 are designed with a diameter of 0.5~1.5mm and a height of 0.3~0.8mm, which increases the contact area with the circuit board by 50%~80% compared to the flat structure, and reduces the dependence on installation precision.

[0025] The material of the protective layer 24 is fluorocarbon resin, and a transparent fluorocarbon resin layer with a thickness of 10~30μm is coated on the surface of the base layer 21, the reinforcing layer 22 and the conductive protrusions 23, providing wear resistance, oxidation resistance and moisture protection, while maintaining electrical conductivity.

[0026] The preparation method is as follows:

[0027] First, silica gel molding, using two-color injection molding process, embedding conductive particles 3 in the silica gel base 1.

[0028] Second, conductive layer printing, forming the base layer 21 and the reinforcing layer 22 in turn by screen printing, and curing at 80~120℃.

[0029] Third, protrusion molding, using mold hot pressing method to form array conductive protrusions 23 at the bottom of the silica gel base 1.

[0030] Fourth, protective layer coating, and spraying fluorocarbon resin protective layer 24 on the bottom of the silica gel base 1 and curing by ultraviolet light.

[0031] The test is as follows:

[0032] The hardness of the silica gel base 1 is Shore A 50±5, and the base layer 21 and the reinforcing layer 22 are arranged at the bottom of the silica gel base 1.

[0033] The silver-plated copper powder of the conductive particles 3 has a particle size of 10μm and accounts for 15%.

[0034] The conductive protrusions 23 are designed with a diameter of 1.0mm, a height of 0.5mm and a pitch of 2.0mm.

[0035] Test results: after 10,000 presses, the button trigger force remains within ±5% deviation, and the resistance change rate is 3.2%.

[0036] The thickness of the protective layer 24 is 20μm.

[0037] Environmental test: under IP67 protection level, salt spray test for 500 hours without performance attenuation.

[0038] Through the test of the embodiment, the electrical conductivity is improved: the contact resistance is ≤10Ω, the traditional product is ≥50Ω, and the resistance change rate is <5% after 10,000 presses.

[0039] Durability is enhanced: the protective layer prolongs the service life of the conductive layer to more than 100,000 times, while the traditional product is about 30,000 times.

[0040] Environmental adaptability: stable performance in 90% humidity or -30~100℃ temperature environment.

[0041] It is to be noted that the relational terms herein, such as first and second, and the like, are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the statement "includes one of A and B" does not foreclose the existence of other elements or steps than A and B.

[0042] While the embodiments of the present application have been illustrated and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made therein without departing from the spirit and scope of the application, which is defined by the following claims and their equivalents.

Claims

1. A silicone key structure based on conductivity enhancement, comprising a silicone base body (1), characterized in that: The bottom of the silica gel base (1) is provided with a conductive layer (2) and conductive particles (3) embedded in the silica gel base (1); The conductive layer (2) comprises a base layer (21), the surface of the base layer (21) is provided with a reinforcing layer (22), and the bottom of the base layer (21) integrally extends a conductive bump (23), and the surface of the base layer (21), the reinforcing layer (22) and the conductive bump (23) is provided with a protective layer (24).

2. The conductive property based silicone key structure of claim 1, wherein: The reinforcing layer (22) is interwoven by silver nanowires and carbon fibers in a mass ratio of 3:1-5:

1.

3. The conductive-based silicone key structure of claim 1, wherein: The conductive bump (23) is semispherical, and the height-to-diameter ratio is 1:1.5-1:2.

5.

4. The conductive property-based silicone key structure of claim 1, wherein: The material of the protective layer (24) is fluorocarbon resin.

5. The conductive-boosted silicone button structure of claim 1, wherein: The material of the base layer (21) is high-density silver-carbon composite material.

6. The conductive property-based silicone key structure of claim 1, wherein: The material of the conductive particles (3) is silver-plated copper powder, and the particle size is 5-20 μm.

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