Conductive adhesive is a kind of adhesive that can bond various materials and has conductive properties, so it can be divided into two types: structural type and filling type. The structural type is conductive adhesive? Polymer materials are conductive, and filling type means that adhesive as a matrix needs to be added with conductive filler to have conductive effect. Because the materials of conductive polymers are complicated, most of them still use filled conductive adhesives. Today, Xiaobian wants to introduce the principle of conductive adhesive and its components. Friends who want to know must not miss it.
the principle of conductive adhesive
the conductive mechanism of conductive adhesive is considered to be that conductive particles contact each other to form an electrical path, which makes the conductive adhesive conductive. The stable contact between the adhesive layer and the store is formed by the curing or drying of conductive adhesive. Conductive adhesive containing solvent, before curing or drying, conductive particles exist separately in the adhesive, and there is no continuous contact between them, so it is in an insulating state. After the conductive adhesive is cured or dried, the volume of the adhesive shrinks due to the volatilization of the solvent and the curing of the adhesive, so that the conductive particles are in stable and continuous contact with each other, thus showing conductivity.
due to the tunneling effect, a certain current path can also be generated between conductive particles in the conductive adhesive. When the conductive particles are not in contact with each other, there is an isolation layer between the particles, which hinders the directional movement of free electrons in the conductive particles. According to the concept of quantum mechanics, for a microscopic particle, even if its energy is less than the energy of the barrier, there is not only the possibility of reflection, but also the possibility of penetration, which is also called tunneling effect. Electron is a kind of microscopic particle, so it has the possibility of blocking through the isolation layer between conductive particles. According to the above analysis, the conductivity of conductive adhesive can be divided into three types: < P > A part of conductive particles completely contact each other to form a current path;
Some conductive particles are in incomplete continuous contact, in which a current path is formed between conductive particles that are not in contact with each other due to the tunneling effect;
some conductive particles are completely continuous, and the isolation layer of conductive particles is completely continuous, which is electrical insulation.
what is the composition of the conductive adhesive
The conductive filler added to the filled conductive adhesive is usually metal powder. Due to the different kinds of metal powder, particle size, structure and dosage, as well as the different types of adhesive matrix, the types and properties of conductive adhesives are also very different. Table 2 lists the resistivity of some metals. At present, silver powder filled conductive adhesive is widely used. In some occasions where the requirements for electrical conductivity are not very high, copper powder filled conductive adhesive is also used. Synthetic resin has conductivity after adding some metal filler or conductive carbon black. The carbon can be any amorphous carbon, such as acetylene black or pulverized graphite powder. Fine silver powder is commonly used in conductive epoxy adhesive or conductive coating. Its advantage is that it has appropriate conductivity to salts and oxides, so it can allow a small amount of oxidation or corrosion. The anticorrosion process is not as important as the thin adhesive layer method, in which interfacial resistance plays an important role.
finally, I want to talk about the composition of conductive adhesive. In fact, silver products are more suitable as conductive materials for gold, because it is relatively cheap and has low resistance. Under the condition of high temperature, silver will migrate by electrolysis, while gold will not migrate. So everyone knows the principle of conductive adhesive and what components of conductive adhesive are? I want to know more about this and learn about the decoration of Tuba Rabbit. I believe you will be disappointed and hope to help you.
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