Manufacturing Method for Conductive Rubber Keypads
Principally, the resin matrix of type conductive rubber keys can utilize various types of adhesives, commonly including epoxy resins, silicone resins, polyimide resins, phenolic resins, polyurethane, and other thermosetting adhesive systems. After curing, these adhesives form the molecular framework structure of the conductive rubber keys, ensuring mechanical and bonding properties, allowing for the formation of pathways for conductive fillers. Epoxy resins can cure at room temperature or below 150°C and offer extensive design versatility. Currently, conductive rubber keys based on epoxy resin are predominant. The conductive particles of the conductive rubber keys must have good conductivity, with particle sizes within an appropriate range, which can be added to the conductive rubber key matrix to form conductive pathways. Conductive fillers can include powders of gold, silver, copper, aluminum, zinc, iron, and nickel, as well as graphite and some conductive compounds. The working principle and manufacturing methods of conductive rubber keys.
Conductive rubber is an adhesive material that possesses conductivity after curing or drying. It primarily consists of a matrix resin and conductive fillers, which are conductive particles. The matrix resin binds these particles together, forming conductive paths to achieve electrical connectivity between the bonded materials.
Conductive rubber is primarily composed of a resin matrix, conductive particles, dispersant additives, and auxiliaries. Currently, the conductive rubber switches on the market are mostly filled types.
Conductive rubber buttons operate on two key conduction principles.
The tunneling effect causes particles within conductive rubber keys to form certain current pathways. When the directional movement of free electrons within conductive particles is hindered, this hindrance can be regarded as a potential barrier. According to quantum mechanical concepts, for a microscopic particle, even if its energy is less than the energy of the barrier, it may not only be reflected but also tunnel through it. The phenomenon of a microscopic particle penetrating a barrier is known as the tunneling effect or penetration effect.
Electrons, being microscopic particles, can potentially be blocked by insulating layers between conducting particles. The probability of electrons passing through an insulating layer depends on the layer's thickness and the difference in energy between the layer's potential barrier and the electron's energy. The thinner the layer and the smaller the difference, the greater the probability of the electron passing through. When the insulating layer's thickness is reduced to a certain point, electrons can easily penetrate this thin layer, turning the insulating layer between conducting particles into a conducting layer. The conducting layer caused by the tunnel effect can be equated to a resistor and a capacitor.
Conductive particles interconnect to form conductive pathways, enabling the conductive rubber keypad to conduct electricity. The stable contact between particles in the adhesive layer is caused by the curing or drying of the conductive adhesive. Before the conductive adhesive cures or dries, the conductive particles exist individually within the adhesive, without continuous contact with each other, hence they remain in an insulated state. Post-curing or drying of the conductive adhesive, due to solvent evaporation and the curing of the adhesive, the adhesive's volume shrinks, placing the conductive particles in a stable and continuous state, thereby exhibiting conductivity.。
Yongle Rubber & PlasticThe company has successfully passed the ISO9001 certification. We specialize in manufacturing platinum silicone tubes, peristaltic pump silicone tubes, food molding silicone components, and silicone products. We also offer customized production of sealing components for plastic products. Our competitive strategy revolves around "Better products, better service, better image," constantly driving innovation in management and transformation to enhance our overall corporate competitiveness.
