The Pros and Cons of Through-Hole Technology

We recently discussed the benefits and limitations of surface mount technology (SMT), so today we would like to look at the alternative: through-hole technology.

Through-hole technology became the industry standard in the 1940s, replacing earlier assembly techniques such as point-to-point technology. Through-hole is an easy form, with leads threaded through pre-drilled holes forming a criss-cross pattern on the opposite side. The leads are bent into 90-degree angles in opposite directions for mechanical strength, then soldered in place.

We recently discussed the benefits and limitations of surface mount technology (SMT), so today we would like to look at the alternative: through-hole technology.

Through-hole technology became the industry standard in the 1940s, replacing earlier assembly techniques such as point-to-point technology. Through-hole is an easy form, with leads threaded through pre-drilled holes forming a criss-cross pattern on the opposite side. The leads are bent into 90-degree angles in opposite directions for mechanical strength, then soldered in place.

Through-Hole Components

There are two types of through-hole components: axial and radial leads. Both of these components are “twin” lead components with distinct advantages.

• Axial lead components run through a component in a straight line (along the “axis”), with the end of the lead wire exiting the component on either end. Both ends are then placed through two separate holes on the board, providing the component with a closer, flatter fit. These components are preferred when looking for a snug, compact fit. Axial lead configuration may come in the form of carbon resistors, electrolytic capacitors, fuses, and light-emitting diodes (LEDs).

• Radial lead components protrude from the board, with its leads located on one side of the component. Radial leads occupy less surface area, making them preferable for high-density boards. Radial components are available as ceramic disk capacitors.
  
  

Advantages of Through-Hole Technology

Despite the rise of surface-mount technology, through-hole has held its own because of its reliability. Through-hole soldering creates a stronger bond between components and the board, making it perfect for larger components that will undergo high power, high voltage, and mechanical stress, including:

• Transformers
• Connectors
• Semi-conductors
• Electrolytic capacitors

Because components run through the board, they can also withstand more environmental stress. That is why through-hole technology is the preferred method for military and aerospace products that experience extreme accelerations or high temperatures. Their durability also makes them the best choice for prototyping and testing.

Disadvantages of Through-Hole Technology

The main disadvantages to THT come from the need to drill multiple holes through the board. This lengthens production time and increases production costs. The holes, while necessary to secure components in place, also limit available space and routing area for tracing signals.

High-Quality Printed Circuit Board Assembly in Maryland

When it comes to dependable, expert PCB assembly, Telan Corporation has been an industry standard for over 35 years. We are the go-to electronics manufacturer in Maryland, offering both surface-mount and through-hole technology. With fast quotes, quick turnarounds on prototypes, and fast production delivery, Telan Corporation is partner you can rely on.

Contact us today and discover why we are the best PCB assembly service in Maryland.