What are the common adhesives used for circuit boards?
29 December 2023
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Various types of adhesives are often used in the PCB manufacturing process, and these different types of adhesives offer unique properties and benefits for a variety of applications in the electronics industry. Proper use ensures the safe operation, heat dissipation, insulation and protection of electronic equipment in a variety of demanding conditions. Let's take a closer look at the properties and applications of these adhesive materials.
Hot Melt Adhesives
Hot melt adhesive is a solid hot melt adhesive. At a certain temperature it will melt, heat bonding after regular temperature curing. Has the advantages of fast bonding, high strength. Mainly used for electronic components fixed, wire bonding and other electronic components bonding.
Thermally Conductive Silicone
Thermally conductive silicone, also known as thermal paste or thermal paste, is a high thermal conductivity and insulation of silicone materials. It can be kept in the range of -50°C to +250°C for a long time in the form of soft fat. It has excellent electrical insulation properties and thermal conductivity. It is mainly used for connecting heat generating elements such as power tubes with heat sinks, increasing their contact area and effectively conducting and radiating heat. Widely used in electronic products internal heat dissipation.
Yellow glue
Yellow glue is a water-based self-bonding gel adhesive, with a pungent odor. It has excellent insulation, moisture-proof, shockproof and thermal conductivity, can make electronic components in harsh conditions more secure operation.
Its curing speed and environmental temperature, humidity and wind speed. When the yellow glue coated parts are placed in the air, it will slowly crust. The operation should be completed in time to avoid too much skinning on the surface. Mainly used for electronic products such as inductors, coils, transformers and other parts of the fixed, sealed, protected and insulated electronic components.
Red Glue
Red adhesive is a polyolefin adhesive, heat curing occurs easily. When the temperature reaches 150 ° C, red glue from paste to solid. It can be fixed on the circuit board through the way of dispensing or printing of the chip components. It is cured by heating in an oven or reflow soldering. When the board is mounted on both sides of the board, the red adhesive prevents the small backside components from falling out of the oven when they are soldered over the wave soldering.
The advantages of red adhesive are: 1. stable adhesive strength; 2. viscosity and rheology suitable for stencil printing, the amount of glue under the stable and will not miss the brush or edge too much; 3. high stability of preservation; 4. to prevent high-speed placement of the components occurring when the off-set. Mainly used to fix the circuit board on the chip components.
Silicone adhesive
Silicone adhesive is a liquid material dissolved in water, after drying will be cured into a adhesives-like solid. It is commonly used in glass technology and sealing applications. Mainly used for electronic modules, sensors and other potting, insulation and flame retardant, as well as electronic components bonding and fixing.
The above is some of the PCB industry in the manufacturing process commonly used in the adhesives, the rational use of a variety of adhesives is also necessary for the manufacture of high-quality products.
