In electronics manufacturing, two common types of components are SMD (Surface-Mounted Device) and THT (Through-Hole Technology). Understanding the difference is crucial for PCB design, production efficiency, and equipment selection. This guide will explain what SMD components are, how they differ from THT, and why these distinctions matter.

Related reading: What Is SMT? A Complete Overview of Surface Mount Technology | SMD vs SMT: What’s the Difference?

Table of Contents

• 1. What Is an SMD Component?
• 2. What Is a THT Component?
• 3. Key Differences Between SMD and THT
• 4. Advantages and Disadvantages
• 5. Practical Implications in Electronics Manufacturing
• 6. Conclusion

1. What Is an SMD Component?

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SMD stands for Surface-Mounted Device. These are electronic components designed to be mounted directly on the surface of a printed circuit board (PCB). Common examples include:

• Resistors
• Capacitors
• Integrated Circuits (ICs)
• Diodes and LEDs

SMD components are typically small, lightweight, and designed for high-density PCB layouts. They are often supplied in tape or tray packaging for automated placement using SMT equipment.

Learn more about SMD components: What Is SMD? Understanding Surface-Mounted Devices

2. What Is a THT Component?

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THT stands for Through-Hole Technology. These components have leads that pass through holes in the PCB and are soldered on the opposite side. Examples include:

• Electrolytic capacitors
• Large ICs or connectors
• Switches and relays

THT components are larger, mechanically stronger, and often used in applications where durability is more important than miniaturization.

For process overview, see: What Is SMT? A Complete Overview of Surface Mount Technology

3. Key Differences Between SMD and THT

Feature	SMD	THT
Mounting Method	Placed on PCB surface (SMT)	Leads go through PCB holes and are soldered
Size	Small, compact	Larger, bulkier
Production Method	Automated pick-and-place and reflow soldering	Manual insertion or wave soldering
Mechanical Strength	Less mechanically robust	Stronger, better for connectors or stress-prone parts
Application	High-density, miniaturized PCBs	Durable, high-current, or high-voltage applications

4. Advantages and Disadvantages

SMD Advantages

• Supports miniaturization and high-density PCB designs
• Suitable for automated high-speed production
• Lower material and assembly cost per unit

SMD Disadvantages

• Less mechanically strong than THT
• Repair and prototyping can be more challenging

THT Advantages

• Mechanically stronger
• Ideal for high-power or stress-prone components
• Easier for prototyping and manual assembly

THT Disadvantages

• Not suitable for miniaturized, high-density PCBs
• Slower production and higher labor cost

5. Practical Implications in Electronics Manufacturing

Understanding the difference between SMD and THT helps manufacturers make key decisions:

• Selecting the right components and packaging
• Choosing the appropriate assembly process (SMT vs. THT)
• Optimizing production efficiency and equipment usage
• Planning for repair, testing, and quality control

For a deeper dive into the process side, see: SMD vs SMT: What’s the Difference?

6. Conclusion

Both SMD and THT components have unique advantages and applications. SMD is ideal for high-density, automated assembly, while THT provides mechanical strength for stress-prone or high-current circuits. Knowing when and how to use each type is essential for PCB designers, manufacturers, and electronics engineers.

Explore more related topics: What Is SMT? A Complete Overview of Surface Mount Technology | What Is SMD? Understanding Surface-Mounted Devices | SMD vs SMT: What’s the Difference?