Cleaning of Leadframes & Discrete Components

Leadframe-based, discrete components, such as MOSFETs, IGBTs and SOTs are soldered onto the base substrate respectively the leadframe during the die attach process. The usual wire bond connection is partially replaced with the so called clip bonding technology where the connection between the die and lead consists of a copper bridge that is also soldered with a paste. Essentially, when mainly using lead based solder, high peak temperatures during soldering increase the requirements for the cleaning process:

• Complete flux removal from the soldering process
• Removal of all inorganic stains and activation of the copper surfaces
• Material compatibility of the cleaning agent with all materials, e.g. copper and chip passivations