A STUDY ON DESIGN OF SURFACE MOUNTING TECHNOLOGY AND IT’S TOOLS

Abstract

ABSTRACT

SMT designs are a radical departure from their thru-hole counterparts due to
trace/component spacing’s , size, and sensitivity to processing. It is mandatory that a design
be manufacturable in the very beginning as tweeks in the process and rework must be
avoided. ZERO DEFECT SOLDERING must be the goal for all SMT designs, and the path
starts with the design of the board. For a board to be manufacturable one must be able to
first assemble (place) components accurately andt hen solder those components to the
substrate (PC board) with reliable solder joints ,inspect those joints, test the assembly, and
finally replace any defective components. Rework, a hideous term which implies constantly
fixing a production problem, must be eliminated by design and process control. Only the
design aspect will be Considered, but proper process control is as important as design for
both high yield and reliability .Zero defect soldering requires proper solder fillet formation.
Important factors that determine fillet formation are slightly different between reflow and
wave soldering and will be considered separately. Common design factors will be considered
as a third category and will include tooling holes, test points, and handling stress.
Keywords: SMT, Soldering, PCB, Pin hole, Reflow process, SMT, Soldering, Zero defect