CS970 is a formic-acid high-lead solder paste engineered exclusively for formic-acid reflow. It is designed for die attach and other applications with stringent residue requirements. Conventional high-lead solder pastes suffer from residue contamination, which can degrade wire bond strength and induce delamination of molding compounds on surfaces that are difficult to clean thoroughly, seriously compromising reliability. The flux in CS970 substantially decomposes or volatilizes during soldering, leaving virtually no flux residues after bonding. The flux will not contaminate chips or lead frames during the soldering process, ensuring optimal wire bond and encapsulation performance.

CS970 delivers outstanding void performance, achieving ultra-low void rates on common metallic interfaces.

CS970 can be used standalone under formic-acid atmosphere or in combination with preformed solder foils. When paired with preformed solder foils, standard thermal profiles for preforms are applicable.

Core Advantages

• Zero or ultra-low flux residue 

• Ultra-low void 

• Minimal spattering and solder balls

 • Stable printing and dispensing performance 

• Wide process window, compatible with various thermal profiles 

• Suitable for common metallic interfaces including copper, nickel, silver and gold 

• No cleaning required after soldering