In the given article we will look into the Surface Mount Technology (SMT) for the PCB electronics. But before that we will establish a basic concept about what exactly a PCB also known as Printed Circuit Board is. A PCB is a type of a circuit board in which a board, called a substrate, made from epoxy glass, is used to made traces on it made from copper. These traces are responsible to carry out the electric current from or within the components placed on the circuit board.
Let’s jump directly now into the pool of our topic that is SMT. The SMT widely dependent on four main factors: Co-efficient of thermal expansion, Glass transition temperature, dielectric properties and the cost. These factors are very important in a PCBA manufacturing.
When ceramic mounting devices are used on an epoxy glass substrate, the cracking issues have been sight very often. That is because of the big difference in co-efficient of thermal expansion between the epoxy glass and ceramic materials. Therefore; at the time of PCB circuit board making, these factors should be considered wisely.
Despite of the facts state above, the glass epoxy substrates are most widely used in the circuit boards containing surface mount devices. Because it matches good compatibility with the plastic Surface Mount Devices (SMDs) therefore they are used in many circuits because most of the circuits have plastic SMDs. But for the special purpose applications of the PCB electronics, much research is needed to make sure that the substrate and the SMDs materials’ coefficient of thermal expansion should compatible with each other.