The Disadvantages of Using Surface Mount Technology

Those interested in a quick turn PCB will want to carefully explore and research the different types of construction for these critical boards. Although for many professionals surface- mount technology (SMT) has replaced older techniques, such as through- hole technology, that does not mean that the system is completely without fault. There are several disadvantages that those considering this technology should be aware of before they make a final decision.

Disadvantages to be aware of with SMT

Difficulty with repairs

Many professionals find that it is more of a challenge to manually put together the prototypes or to repair individual components. It often requires more training and experience to successfully complete these steps, particularly as many devices with this technology are very small and have minimal lead spacings.

Incompatible with breadboards

Breadboards are commonly used to create quick prototypes that can be used right away. To use these breadboards, developers must instead use a custom PCB, occasionally a breakout board, or a stripboard style protoboard. If the developer really wants to use the breadboard, they can use a “dead bug” breadboard system.

Not suitable for regular, high mechanical stress or high voltage

PCBs that will regularly be exposed to significant mechanical stress may not fare well with surface mounting. Typically boards mounted this way will have frequent attaching and detaching when mounted in this fashion.

Similarly, the mounting system is not a good fit for boards that will be required to withstand very high power or high voltage parts, such as in power circuitry. When these types of boards are needed, such as for transformers, a combination of SMT and through-hole construction will generally be used.

Soldering and joint concerns

As technology continues to march towards ultra-fine pitch technology, soldering has become an increasing concern. As less solder is allowed for each joint with the new technology, voiding has been a problem. The increase in voids can weaken the joint and result in failure. 

Surface mount technology has become increasingly popular in the world of PCBs. As people explore the advantages it brings to the technology world, however, it is also important not to overlook the disadvantages that might occur. When developers have a strong idea about both the pros and cons of a system, they will be better equipped to choose the best system to put together boards and achieve the desired end result.