Can SMT technology speed upPCB production?
Today's mass-producedelectronic hardware is manufactured using the surface mount technology or SMT.Not without reason! SMT PCBS has a long way to go in speeding up PCBAproduction, in addition to offering many other advantages.
Surface Mount Technology
Essentially, surface mounttechnology (SMT) takes the basic concept of through-hole manufacturing andcontinues to make significant improvements. When using SMT, PCBs do not need tobe drilled. Instead, all they have to do is utilize solder paste. In additionto increasing speed, this dramatically simplifies the process. While it is truethat SMT mount assemblies do not have the strength that through-hole mountassemblies have, they offer many other advantages that can offset this problem.
Surface mount technologygoes through the following 5 steps.
1. PCB production This isthe stage where the PCB is actually produced with solder dots
2. Solder is deposited onthe pads to fix the components to the board
3. Placing the components onthe precise solder points with the help of machines
4. Bake the PCB to hardenthe solder
5. Inspect the finishedassembly
The reasons that make SMTdifferent from through-hole include
l The space problems thatare widely seen in through-hole mounting can be solved by using surface mounttechnology. SMT also offers design flexibility because it provides PCBdesigners with the freedom to control the creation of specialized circuits. Thereduced component size means that more components can be accommodated on asingle board and fewer boards are required.
Components in SMT mounts arelead-free. Lead lengths are shorter for surface mount components, reducingpropagation delays as well as package noise.
The density of componentsper unit area is higher because it allows components to be mounted on bothsides
It is suitable for highvolume production, which reduces costs
The reduced size leads toincreased circuit speed. In fact, this is one of the main reasons why mostmanufacturers choose this method.
The surface tension of themolten solder pulls the assembly into alignment with the pads. In turn, thisautomatically corrects any small errors that may occur in component placement.
SMT has proven to be morestable in conditions where there is a lot of vibration or shaking.
SMT parts are usuallycheaper than comparable through-hole parts.
Importantly, since nodrilling is required, SMT can significantly reduce production time. Also, SMTcomponents can be placed by the thousands per hour, while through-hole mountscan be placed at a rate of less than one thousand. In turn, this leads to the productionof products at the desired speed, which further reduces time to market. So ifyou are looking to speed up your PCB production time, then SMT is definitelythe answer. By using Design for Manufacturing (DFM) software tools, the needfor rework and redesign of complex circuits can be greatly reduced, thusfurther increasing speed and the possibility of complex designs.
All of this does not meanthat SMT does not have its own inherent disadvantages. SMT can be unreliable ifit is used as the only method of fixing components that are exposed to largeamounts of mechanical stress. Components that generate a lot of heat or aresubjected to high electrical loads cannot be mounted using SMT. This is becausethe solder will melt at high temperatures. Therefore, it is likely thatthrough-hole mounting will continue to be used in cases where there arespecific mechanical, electrical and thermal factors that make SMT fail.Similarly, SMT is not suitable for prototyping because components may need tobe added or replaced during the prototyping phase, and high density boards maybe difficult to support.