An electronic manufacturing company used Master Bond EP35CA for the assembly of measurement devices. This compound was selected only after a long-term evaluation process versus many competitive products. The application required bonding metal to metal and ceramic to ceramic surfaces. EP35CA product met challenging service requirements for these devices such as high lap shear strength, superior electrical insulation properties, moisture and chemical resistance, including exposure to chlorinated solvents.
After a long history of success with EP35CA, the measurement device was miniaturized and had to be sold at a more competitive price. Our research and development team went back to the lab to formulate a new product that maintained the properties of EP35CA, while meeting faster processing speed requirements essential to optimizing productivity. Eventually EP35CA was discontinued and Master Bond EP41S-5 became the system of choice. This heat curing two component system is solvent free, has an extended working life, low shrinkage and adheres well to thin-walled metallic surfaces. It can also be used for gap filling applications.
This two component epoxy has a mixed viscosity of 25,000-30,000 cps and can be easily dispensed with a gun applicator. Expediting the cure with heat was not a problem. This low shrinkage material has formidable strength properties, and most importantly, is resistant to methylene chloride, phenol (10%) and nitric acid (30%) to satisfy stringent device standards. It also delivers excellent resistance to gasohol. Continuous and intermittent liquid immersion testing was done for long-term exposure under variable stress and load conditions for the required substrate combinations. EP41S-5 is serviceable up to 300°F.
Traditional metal and ceramic substrates were now replaced with dissimilar engineering composite and aluminum surfaces for lightweighting purposes. Another benefit was improved aesthetics resulting in a more attractive looking device. The new structural bonding material EP41S-5 proved effective in surpassing both the processing and performance accomplishments of the EP35CA system, enabling our customer to sell more units at a more affordable price.