Find more on industrial components from latest blogs

The classification of adhesives

First, epoxy resin adhesive
The epoxy resin adhesive is divided into two types: single-component and two-component. The two-component adhesive is cured at room temperature, requiring two groups of stars carefully mixed in an appropriate ratio, which makes the two-component adhesive is unlikely to apply to the production. A single-component adhesive sealant is cured at a higher temperature, and the curing time depends on the temperature.



Second, a polypropylene binder
It is the same with the epoxy resin, polypropylene is the thermosetting adhesive formed by a single-or two-component, but with the unique chemical properties of rapid curing. Polypropylene adhesive is hardened relying on the same dimerization reaction with an epoxy resin, but the curing mechanism is different. This adhesive takes use of ultraviolet light or heating to achieve curing. UV light causes the decomposition of peroxide compounds, adhesives and the formation of the radical or the product of a single electron. Since this binder has higher production efficiency and can achieve online curing between the element affixing and the wave soldering, it is widely used for surface mounting. There is a significant difference between polyacrylic adhesive and an epoxy resin adhesive, that most of the polyacrylic adhesive are anaerobic. Accordingly, in order to prevent the natural curing, they should not be wrapped in a sealed vessel. In order to avoid curing in the reservoir, the binder must be breathable.

Third, other adhesives used for the surface mounting
Urethane and cyanoacrylate, and carbamates is easy to be damped, and smt adhesive needs to be stored in a dry place to prevent the premature polymerization. After the dimerization, they can neither resistant water, nor resistant solvent. Therefore, these materials are rarely used in surface mounting. Cyanoacrylate is curing by absorbing moisture without heating, and for the SMT, the cohesive effect of the cyano-acrylate is too fast, and requires a good surface. The adhesive with too fast curing is not suitable for surface mounting, because sometimes it requires a certain time interval between applying an adhesive paste and discharge element. In addition, cyanoacrylate ester is a thermoplastic adhesive, which may not stand the heat wave soldering.

Requirements of surface mount technology on adhesives

First, the chemical composition is simple, and easy to manufacture;
Second, have a good filling and long term storage;
Third, good chemical stability and insulation, fast curing and the curing temperature is below 150 °C;
Fourth, the curable adhesive has a sufficient strength, and it is possible to reliably fix the components, and it is non-corrosive to the circuit board; Fifth, high temperature resistant and it will not melt in wave soldering temperature.

Thanks to the seven-year arduous pioneering, www.zscnr.com has marched into the stage of rapid development. Confronting to the domestic competition of adhesive, the company takes slow and steady efforts to catch up and now it has created a well-known brand among the domestic adhesive industry. The whole company will tenaciously strive to enter into the top 100 of the domestic adhesive industry.