SMT Assembly Consideration

Surface mount technology or SMT is a widely-used alternative to older through hole during printed circuit board design and PCB manufacturing process. Though through hole manufacturing still has a place, SMT has largely replaced them where size, weight and automated manufacturing processes are considered.

SMT uses surface mount devices (also abbreviated as SMDs) to replace larger, heavier, and more cumbersome counterparts used in through-hole PCB construction. Today, more and more PCB devices are available as SMDs or packages, making SMT board design and manufacture more practical and cost-effective.

Surface mount technology has promoted the use of electronic devices that are impossible or not practical with the older through-hole fabrication techniques.

Due to the nature of SMT board structure and smaller and lighter components, automation of the PCB construction is facilitated and has become very effective for manufacturing, especially for mass production. To get the maximum manufacturing advantage, SMT construction must be mechanized as much as possible.

SMT assembly manufacturing has following advantages:

a.Drilling holes are nearly or completely eliminated with SMDs connecting the board surface directly.

b.Reliability is enhanced because it is not necessary to mount the component leads through holes for subsequent soldering. Soldering SMDs to surface pads is quicker and easier with assembly time reduced and quality improved.

c.SMT assembly is highly automated, speeding up production and reducing customer turnaround time.

d.Through-hole manufacturing needs to be carefully aligned with the drilling hole, and leads are typically pre-formed to accommodate a particular PCB layout and component placement. SMT assembly eliminates most SMD placement interference, allowing for more automation, thereby reducing costs. SMD leads are small or even none at all.