From electronic goods to high performance servers, usage of Printed Circuit Boards (PCBs) has been critical in the day-to-day living. Surface Mounted Technology (SMT) and through-hole Technology (THT) are two critical mounting schemes used in the fabrication of PCBs over the years. In the earlier 1980’s, SMT became more popular and superior soldering practice used in technological devices. The conventional Through-hole technology has gone obsolete as the devices became more compact due to smaller size and increased capability. Read this post to understand the difference between the two technologies. The post will also answer the question, “Does Through-hole technology still holds relevance in the modern PCB fabrication?”
Understanding Through-hole Technology:
Through-hole Technology involves the usage of leads on the electrical component, which are inserted inside the holes drilled on the circuit board. These leads are then soldered to the pads present on the opposite side of the board. Over the years, this technology was regarded as the most reliable mounting process, as it provides strong mechanical bond between the board and the component. The technology was also used on larger components, which are designed to endure high mechanical stress. However, the considerable flaw with this technology was the additional drilling in the circuit boards, which made the boards more expensive. Also, the presence of holes in the PCBs limited the available routing area for signal traces on the layers present just under the top layer of multi-layer boards.
Deciphering Surface Mounted Technology:
Surface Mounted Technology enables electrical components to be directly placed on the surface of the Printed Circuit Board (PCB). This fabrication method is used on smaller devices. Hence, it is considered as superior method. This mounting technology requires less or negligible drilling of holes in the circuit board assembly. Due to this, high density of connection is possible, as holes don’t congest the routing area on inner or back side area. Also, the physical components placed inside the circuit board are smaller and more compact. This made surface mount technology less expensive than through-hole mounting.
Difference between Through-hole Technology Surface Mounted Technology
Some of the additional differences and distinctions between the mounting schemes are as discussed below:
- Surface Mounting Technology eliminates the problem of space crunch as it doesn’t require any kind of pre-drilled holes like through-hole Technology.
- Pin count in SMTs are higher in comparison to that in THTs.
- SMT technology aids in assembly automation, which makes it feasible for higher volume production at lower cost as compared to through-hole technology.
- As the circuit boards fabricated through SMTs are compact, they acquire high circuit speed in comparison to THTs.
- SMT features advanced design, skill, and technology, which makes it more advanced in comparison to through-hole technology.
- SMT offers better EMC performance due to their smaller radiation loop area and lead resistance.
- SMT technology offers lower resistance and inductance at its connection. The RF signal is also minimum in comparison to through-hole technology.
Both the mounting schemes have proven their adequacy depending upon the customer’s requirement and project consideration. Surface mounting technology assembly has been used in more than 90 percent of PCBs today. Are you in a fix choosing the right scheme for your printed circuit board? It’s time you approach Accelerated Assemblies. The experts at the company will help you choose the right kind of soldering technique by carefully studying and analyzing your circuit board.