ASSEMBLY OF LARGE PBGAS ON PRINTED CIRCUIT BOARD WITH LARGE PQFPS DIRECTLY ON THE OPPOSITE SIDE

Abstract

A two-side no-clean mass reflow process for large plastic ball grid array (PBGA) and plastic quad flat pack (PQFP) packages is presented. Emphasis is placed on the PBGA and PQFP assembly parameters such as the design, materials, and process of the packages and printed circuit board (PCB), solder paste, stencil printing, pick and place, reflow, and inspection. Solder joint reliability of the two-side PCB assembly is evaluated by shear tests and thermal cycling tests.