Grid Arrays With Enhanced Fatigue Life

摘要

Reliability is improved for the mechanical electrical connection formed between a grid array device, such as a pin grid array device (PGA) or a column grid array device (CGA), and a substrate such as a printed circuit board (PCB). Between adjacent PCB pads, a spacing pattern increases toward the periphery of the CGA, creating a misalignment between pads and columns. As part of the assembly method, columns align with the pads, resulting in column tilt that increases from the center to the periphery of the CGA. An advantage of this tilt is that it reduces the amount of contractions and expansions of columns during thermal cycling, thereby increasing the projected life of CGA. Another advantage of the method is that it reduces shear stress, further increasing the projected life of the CGA.

主权项

1. A method of assembling an electronic component onto a printed circuit board comprising:
placing an array of pads on the printed circuit board; applying connective material to the pads; providing the electronic component, having an array of conducting posts, pads of the array of pads being misaligned with conducting posts of the array of conducting posts; mounting the electronic component to the circuit board with the array of conducting posts connected to the array of pads with ends of the conducting posts drawn into closer alignment with the pads, conducting posts of the array of conducting posts being angled from the electronic component to the circuit board when at 20 degrees Celsius.