How to enhance the weather resistance of high-temperature conductive silver adhesive?

Under the trend of miniaturization and high performance of electronic devices, High temperature conductive silver adhesiveAs a key material for connecting internal components in electronic packaging technology, its performance stability is crucial. Especially in extreme environments such as high temperature and high humidity, the weather resistance of high-temperature conductive silver paste directly affects the stable operation of the entire system. So, how to enhance the weather resistance of high-temperature conductive silver paste?

Although silver has excellent conductivity, it is easily oxidized in humid air to form a non-conductive silver oxide film, which affects the conductivity efficiency. Adding antioxidants to the formula can effectively delay the oxidation process of silver. For example, certain phenolic antioxidants can provide active hydrogen atoms that bind with free radicals generated on the silver surface, interrupting the oxidation chain reaction and reducing the oxidation rate, thereby maintaining the conductivity of the silver gel.

In high humidity environments, the infiltration of moisture into conductive silver paste can cause chemical or physical structural changes, leading to an increase in electrical resistivity. Introducing moisture absorbing agents such as molecular sieves and montmorillonite can preferentially adsorb the moisture entering the silver gel, avoiding its damage to the internal structure and properties of the silver gel. At the same time, some moisture-proof agents can also improve the interface compatibility between silver paste and the adhered material, enhancing the bonding strength.

Traditional epoxy resins are prone to degradation at high temperatures, leading to a decrease in conductivity. New resin matrices such as modified epoxy resin and silicone resin can be used. Organic silicone resin has excellent thermal stability and weather resistance. The Si-O bond in its molecular structure has high energy and is not easily broken in high temperature environments, ensuring that the silver paste maintains stable physical and chemical properties at high temperatures, thereby improving overall weather resistance.

Uneven coating thickness can lead to differences in the performance of silver paste. Excessive thickness may cause internal stress concentration and lead to cracking during temperature changes; If it is too thin, an effective conductive path may not be formed. By using high-precision coating equipment such as micro gravure coating machines, slit coating machines, etc., the coating thickness of silver paste is precisely controlled to evenly distribute it on the surface of the adhered material, ensuring consistent performance of silver paste in various parts and reducing weather resistance hazards caused by thickness issues.

The curing temperature and time have a significant impact on the properties of silver paste. Inappropriate curing conditions can result in incomplete or excessive curing of silver paste, reducing mechanical strength and electrical performance. Determine the optimal curing temperature and time curve through experiments for different formulations of silver paste. For example, using a step heating curing method, the silver paste is initially crosslinked at a lower temperature, and then gradually heated to the final curing temperature to fully cure the silver paste, forming a dense and stable structure and improving its resistance to harsh environments.

Moisture and oxygen in the external environment can corrode silver paste and affect its performance. Sealed packaging, such as aluminum-plastic composite bags, vacuum packaging, etc., is used for finished silver adhesive to reduce the impact of environmental factors. Especially for silver paste stored for a long time, good sealed packaging can effectively extend its shelf life and ensure excellent weather resistance during use.

stay Conductive silver adhesiveApply a protective coating with good barrier properties externally, such as poly (p-xylene) coating, Parylene coating, etc. These coatings can effectively block the invasion of moisture, oxygen, and other corrosive substances, providing additional protection for the silver paste. At the same time, the protective coating also has a certain degree of flexibility, which can work together with the silver adhesive to cope with the thermal stress caused by temperature changes, further enhancing the weather resistance of the silver adhesive.
The above data is for reference only, and specific performance may vary due to production processes and product specifications.