ASSESSING THE EFFECT OF FINE PITCH BGA PACKAGES ON MOTHERBOARD DESIGN AND BOARD LEVEL RELIABILITY

摘要

Hand-held electronic devices such as cell phones, PDA's, and gaming products are following a trend of increased complexity while decreasing size and weight. To support this trend, the components that give life to these devices are required to be smaller, even with increased pin counts. In order to meet these demanding size requirements, BGA (Ball Grid Array) packages have decreased ball pitch from 0.8mm to 0.65mm and 0.5mm pitches. However, reducing the pitch on SMT components requires trade-offs in design, assembly and reliability. This paper discusses the advantages and trade-offs of reducing ball pitch for package size reduction. Routing complexity on the component and board level, reduced feature sizes, assembly processes, component test hardware, solder joint life and cost are usually affected when BGA pitch decreases. Each of these trade-offs will be discussed including a method for finding package solutions that best meet customer needs.