Demonstration for rapid prototyping of micro-systems packaging by data-driven chip-first process using nano-particles metal colloids

In order to reduce process complexity, manufacturing cost and lead time, while enhancing electrical and mechanical reliability performance, a new innovative approach, which specifically targeted to prototype and low volume production in microsystems packaging and system in package, is being developed. The approach is rapid prototyping of microsystems packaging by data driven chip-first packaging process using nanoparticle metal colloids. According to the concept of the chip-first process, bare dice and standard passive components are first embedded into a carrier substrate to achieve a common, planar surface. On the planar substrate, polyimide film is laminated to make a dielectric layer. Over the dielectric layers and chip metal pads, silver nanoparticles, which has high conductivity and good adhesion to copper, polyimide, benzocyclobutene (BCB) and liquid crystal polymer (LCP), are deposited by screen printing, forming a three dimensional electrical circuit. This approach is data-driven so that it requires no photo masks and reduces turnaround time and is also less limited by substrate composition and morphology. This approach also eliminates the need for special chip processing such as the need required for flip chip solder bumps and permits using any chip technology and any chip supplier allowing mixed devices. In addition, the data-driven process with metallic nanoparticle avoids the extreme processing conditions required for standard IC fabrication such as wet chemistry processing and vacuum sputtering. Nanoparticles typically measure around 5nm in diameter and can be sintered at plastic-compatible temperatures as low as 220C to form material nearly indistinguishable from the bulk material. These results represent an important step to a system packaging characterized by high density, low cost, and data-driven fabrication for rapid turn-around time.