QPAC® Polyalkylene Carbonate clean-burning binders are used in various challenging metal paste applications where low-temperature decomposition with minimal remaining contaminants is required. The Die Attach process, also known as Die Bonding or Die Mount, is one such application where QPAC® binders can offer significant benefits due to these properties.
The Die Attach process involves connecting a silicon chip to the substrate or die pad of a support structure. Maintaining process integrity is essential in semiconductor manufacturing to ensure high-quality final packaging. Various techniques are used for die attachment.
The emphasis of the research with QPAC® lies on the binder in the Silver Sintering Die Attach process. For this method, a paste made up of monometallic particles and resin is printed onto the substrate in patterns that match the die’s placement and form. The die is then placed on top of the substrate. Heat is used to vaporize the resin and other components. Pressure is then applied. Subsequently, the sintering process occurs, which can be done in an inert atmosphere to prevent oxidation.
The binder is an important part of the process because it helps the integrated circuit/die to adhere to its substrate. It must also debind properly to avoid significant voids in the final connection, which could cause semiconductor device problems.
Furthermore, there is a tendency to employ fine or nano silver powder with a low sintering temperature as it provides improved electrical performance. These smaller silver particles are sintered at temperatures of approximately 200 °C.
QPAC® 40 polypropylene carbonate effectively addresses the rigorous requirements of low-sintering silver adhesives. It is capable of decomposing at relatively low temperatures of 150-200 °C when combined with metal, ensuring the binder is fully decomposed before sintering begins.
Image Credits: Empower Materials
The decomposition of QPAC® 40 results in only CO2 and water, promoting a very fine pore structure in the final product. Moreover, QPAC® 40 is known for its clean decomposition, leaving minimal to no residue in inert and vacuum debind environments. As such, QPAC® 40 is gaining increasing attention and evaluation in the low-temperature nano silver Die Attach process.
Image Credit: Empower Materials