Flexible connection for reflow free fine pitch SOP SMT components

As the device miniaturization, the assembly is becoming more and more dense. The current fine pitch package or micro BGA and other forms of interconnection come to a certain limit, which hindering the development of packaging and assembly. high-density assembly and packaging is facing a lot of new challenges. Today, even the most of the fine pitch packages' pitch maintained at around 0.3mm, it is difficult to continue to shrink, because with the pitch further smaller, there will be a series of problems. For example: package reliability to reduce the emergence of lead bridging, solder ball, cold solder joints and other issues. In order to solve these problems, this paper presents a new way of interconnection. The conductive function is achieved by the conductive silicone rubber between the pad on the PCB and the lead of the packaged device. Due to the presence of pressure, the conductive adhesive is deformed and can be contacted from the top to the bottom. This interconnection form may be adapted to all conductive patterns depending on the spacing of the conductive layers. Conductive adhesive in the conductive material is generally carbon, metal, metal oxide, carrying capacity between 800 ∼ 2800mA / mm2. The current production of conductive silicone spacing between 0.1 ∼ 0.05mm. Through this technology, the size of the packages can be greatly reduced, and the assembly density can be greatly improved.