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Method for improving reliability of rubber and metal composite electric contact

A rubber-to-metal and electrical contact technology, applied in the field of materials or polymer materials, can solve the problems of metal layer falling off, inability to achieve firm bonding, personal safety accidents, etc., and achieve reliable bonding strength, good application prospects, The effect of improving reliability

Pending Publication Date: 2020-04-21
NANTONG MEMTECH TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in production practice, no matter how to strengthen the cleaning of the metal sheet, no matter how various adhesives are used to enhance the adhesion, or self-adhesive rubber is used as the polymer material layer, no matter what quality or grade of polymer material is used, no matter What kind of vulcanization molding process is used, no matter whether a release agent is used in the vulcanization molding process or not, and whether the vulcanization mold is cleaned or not, it is impossible to maintain the metal layer and polymer material layer (or 100% firm adhesion between rubber layers, metal layer does not fall off
The metal layer falls off by itself, or the electrical contacts where the metal layer falls off after light touch sometimes reach the ppm level, seriously affecting product quality and production efficiency
This may be due to the fact that the metal strip used in the preparation of rubber-metal composite electrical contacts has been polluted in various ways during its production and transportation, and the surface of the metal strip has visible and invisible oil stains and stains , rust, dust impurities, chemicals such as paraffin, metal brightener, etc. However, strengthening the cleaning process may not be able to clean all these pollutions
In this case, no matter how good other processes or materials are, they cannot ensure that the metal layer and the polymer material layer (or rubber layer) are firmly bonded and the metal layer does not fall off.
[0005] In the rubber-metal composite electrical contact, if there is separation between the metal layer and the polymer material layer, the metal layer will fall off, which will not only invalidate the switch function of the button, but also cause personal safety accidents, especially when such a When electrical contacts are used in automobiles

Method used

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  • Method for improving reliability of rubber and metal composite electric contact
  • Method for improving reliability of rubber and metal composite electric contact

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Clean the 0.08mm thick stainless steel sheet, and remove the oil on the surface of the sheet as much as possible. By laser etching, a plurality of pits with a diameter of 0.25mm are laser etched on both surfaces of the stainless steel sheet. The shape of the pits is cylindrical, and the depth of the pits is 0.030±0.005mm. The distance between the axes of two adjacent pits is 0.75mm. After the stainless steel sheet is dip-coated with a primer that promotes adhesion to silicone rubber, it is mixed with 0.5% 2,5-dimethyl-2,5-bis(tert-butyl peroxide) at about 165°C. base) Methyl vinyl silicone rubber of hexane was molded for 10 minutes, and the silicone rubber and the stainless steel sheet were bonded together to form a 0.85mm thick silicone rubber-stainless steel sheet.

[0025] Die the obtained silicone rubber-stainless steel sheet into small discs with a diameter of 3.5 mm to obtain a rubber-metal composite electrical contact. Due to the existence of pits, the outer su...

Embodiment 2

[0027] It is basically the same as that of Example 1, but the depths of the pits etched by laser on both sides of the stainless steel are different. During laser etching, the depth of the cylindrical pit etched on one surface of the stainless steel is 0.03-0.05mm, and the depth of the pit etched on the other surface of the stainless steel is 0.001-0.01mm. The side with a pit depth of 0.03-0.05mm will be exposed in the rubber-stainless steel sheet to form the outer surface of the composite sheet, while the side with a pit depth of 0.001-0.01mm will become the inner surface combined with silicone rubber.

[0028] The rubber-metal composite electrical contact prepared by this method has good dust resistance, and at the same time, because the laser etching depth of the inner surface of the metal layer is small, it is beneficial to shorten the laser etching time and improve production efficiency.

Embodiment 3

[0030] Design the pattern for exposure first. Clean the 0.10mm thick nickel sheet with a nickel content greater than 99.5%, and then use metal screen printing on both sides of the nickel sheet to print a photosensitive adhesive with a film thickness of 3-9μm that can be washed off with lye after curing , drying, exposure according to the designed pattern, and development (that is, washing off the photosensitive adhesive on the unexposed part with water), so that both sides are covered by the cured photosensitive adhesive film, but there are exposed evenly distributed metals (that is, Nickel) Nickel sheet with small dots. The diameter of the small metal dots is 0.2 mm, and the distance between the centers of two adjacent metal dots is 0.65 mm.

[0031] Etch the above nickel sheet protected by the photosensitive adhesive with an acid etching solution containing ferric chloride or copper chloride, etch the exposed metal dots on the nickel sheet protected by the photosensitive ad...

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Abstract

The invention discloses a method for improving the reliability of a rubber and metal composite electric contact. The method comprises the following steps: step 1, at least partially etching the innersurface of a metal sheet compounded with rubber through an etching process before the rubber and the metal sheet are compounded and formed so that a fresh surface is generated on the inner surface ofthe metal sheet; step 2, treating the inner surface of the metal sheet through an adhesive or a primer or a coupling agent, or using self-adhesive rubber to realize composite forming of the rubber andthe metal sheet and bonding the rubber and the metal sheet together; and step , slitting the sheet formed by compounding the rubber and the metal sheet into small wafers to obtain the electric contact. The inner surface of the metal sheet compounded with the rubber is partially etched through the etching process so that the inner surface of the metal sheet has a fresh partial surface, and as no grease brought by the metal sheet is contained, the firm combination of the metal sheet and the rubber can be ensured, the metal sheet is prevented from being separated, and the reliability of the rubber and metal compound electric contact is ensured.

Description

technical field [0001] The invention belongs to the field of materials or polymer materials, and in particular relates to a method for improving the reliability of rubber and metal composite electric contacts. Background technique [0002] Rubber buttons can be used in remote controls, game consoles, handhelds, power tools, medical equipment and automobiles. A key component in rubber buttons is the electrical contact (also known as "conductive particle"), which contacts the PCB when pressed , which acts as a circuit switch. [0003] The Chinese Patent Application No. 201010592410.1 for the invention patent "Composite Conductive Sheet" provides a composite conductive sheet composed of a polymer matrix and metal foil, and the surface of the metal foil is uneven. The Chinese Patent Application No. 201110193369.5, the invention patent "Composite Conductive Particles of Pimpled Metal and Rubber", discloses a composite conductive pellet of pitted metal and rubber. The metal surfa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01H11/06H01H1/04
CPCH01H1/04H01H11/06
Inventor 宋燕黄诚丁阳张红梅韩辉升
Owner NANTONG MEMTECH TECH
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