Introduction to Epoxy Conductive Adhesive
Definition of conductive adhesive:
Conductive adhesive refers to a type of adhesive that has both bonding and conductive properties. After curing, it can connect a variety of conductive materials, so that the newly connected parts form a conductive path.
The role of conductive glue:
Improve the adverse effects of welding on electronic components. With the development of electronic technology, more electronic components tend to be miniaturized, lightweight, highly integrated and highly sensitive. They are made of materials that are difficult to weld. The welding process will cause deformation of parts, weak joints, and performance. For problems such as descent, the conductive adhesive is used to bond to avoid the adverse effects of welding.
Types of conductive adhesive:
At present, most of the conductive adhesives on the market are mainly composed of conductive fillers and polymers. According to different polymers, conductive adhesives include acrylic system, epoxy resin system, silicone system, polyurethane system, phenolic resin and polyimide resin system. Among them, epoxy resin has become the most widely used variety in various conductive adhesives due to its convenient curing process and rich formulation design performance.
Features of epoxy resin conductive adhesive:
Has excellent bonding strength. It can achieve good bonding with various substrates;
Rich formula design. With different curing agents, one-component glue or multi-component glue can be prepared. It can realize room temperature curing, medium temperature curing and high temperature curing.
Has good heat resistance;
Low curing shrinkage and stable properties; Good resistance to chemicals.
The composition of epoxy resin conductive adhesive:
Epoxy:
Bisphenol A type epoxy resin Modified epoxy resin
Curing agent: room temperature or heating curing agent can be selected according to process requirements.
Normal temperature curing agents such as polyamide and vinylamine;
Latent curing agents such as acid anhydride and imidazole;
Conductive fillers:
Conductive fillers include carbon, metal and composite conductive fillers.
Domestic high-performance conductive adhesives are mainly conductive adhesives with silver powder as filler, but this type of conductive adhesive has a higher cost.
Metallic conductive fillers:
silver, nickel, copper, aluminum, etc.;
Carbon-based conductive fillers:
carbon black, graphite, carbon nanotubes, graphene, etc.;
Composite conductive filler: generally refers to carbon materials and metal composite materials. Such as silver-modified carbon nanotubes, or mica powder, glass beads, glass fibers and other substrates are plated with silver.
The main application of epoxy resin conductive adhesive:
Instead of solder, it is used to bond electronic components and printed circuit boards, glass, and ceramics, such as various consumer electronics, communication equipment, auto parts, industrial equipment, medical equipment, and solve electromagnetic compatibility (EMC).
Electronic packaging: such as LCD, LED, integrated chips, printed circuit board components, ceramic capacitors and other electronic components and components packaging. Photovoltaic panel bonding: improve the defective rate of cells caused by soldering, reduce costs, and increase the photoelectric conversion rate.
Used as structural adhesive for bonding: metal-to-metal bonding, component lead bonding, battery terminal bonding, etc.
