Modern Electronics Defluxing – Meeting the Low VOC Challenge

Description

[04/2023]

The release of Volatile Organic Compounds (VOCs) into the atmosphere has raised concerns in various states and counties across the USA for many years. In response, regulations have been implemented in certain areas, limiting the use of solvents and cleaners with high VOC content. These restrictions also extend to cleaning agents commonly used in the electronics industry for assembly defluxing. Typically employed in processes involving automated equipment like conveyorized inline cleaners and batch cleaners, these cleaning agents have an average VOC content of around 850 grams/liter when concentrated. This means that when used at working solution concentrations of 10% to 20%, the VOC content can range from 85 grams/liter to 170 grams/liter.

The most stringent VOC emission limitation exists in Southern California, where the district is closely monitored by the South Coast Air Quality Management District (SCAQMD). SCAQMD mandates a limit of 25 grams/liter (according to Rule 1122) for the working solution of chemicals used with inline and batch cleaners, commonly referred to as “cold cleaners.” Exemptions to this rule are granted for specialized applications, such as the production of medical devices or components used in space. However, even in such cases, permits are required to utilize higher VOC cleaning agents, which can be costly and necessitate regular renewal.

In the field of electronics defluxing, there are very few low VOC cleaning agents available. Consequently, in markets where strict VOC limitations are imposed, the concentration of high VOC products in the working solution is reduced to approximately 3% to 5%. Other products currently classified as low VOC contain a high water content in their concentrate. Both of these approaches restrict cleaning efficiency and the overall performance of the cleaning agent.

In this study, the authors set out to develop a cleaning agent using low VOC raw materials and low water content. The aim was to create a formulation that could be used at higher concentrations, thereby achieving the necessary cleaning performance for electronic assembly defluxing. Cleaning trials were conducted to compare the newly formulated low VOC cleaning agent with existing products, assessing its performance through visual inspections of low standoff components and compatibility tests on sensitive metals.