Despite the rapid rise of surface mount technology (SMT), through hole PCBs continue to play a critical role in the electronics industry, especially in high-reliability applications. Their durability, strong mechanical bonds, and ease of prototyping make them ideal for sectors like aerospace, automotive, industrial control, and power electronics. As we move further into 2025, many engineers and OEMs still rely on through hole technology for specific design and performance needs.
1. What Is a Through Hole PCB? Definition and Key Characteristics
A through hole PCB is a printed circuit board that uses drilled holes to mount electronic components with leads (or pins). These leads are inserted into the holes and soldered to pads on the opposite side of the board. This creates a strong mechanical and electrical connection, often preferred for components that face physical stress or require precise alignment.
Key characteristics of through hole PCBs include:
- Drilled plated or non-plated holes
- Use of axial or radial leaded components
- Strong solder joint integrity
- Double-sided or multilayer configurations
2. The History and Evolution of Through Hole Technology
Through hole technology dates back to the 1950s and was the industry standard until SMT emerged in the 1980s. Initially, all components were inserted manually and soldered on the opposite side. Over time, automated insertion machines improved production efficiency. Although SMT now dominates in consumer electronics, through hole PCBs are still valued for robustness and ease of inspection.
3. How Through Hole Components Are Mounted on PCBs
Through hole components are mounted by inserting their leads into pre-drilled holes in the PCB. There are two main mounting methods:
- Manual Insertion: Used in low-volume or prototyping environments.
- Automated Insertion: Ideal for high-volume production with wave soldering processes.
After insertion, the leads are soldered on the underside, typically using wave soldering or selective soldering machines.
4. Common Types of Through Hole Components
Some widely used through hole components include:
- Resistors (axial and radial)
- Capacitors
- Diodes
- Transistors
- Connectors
- Transformers
These components are often chosen for their heat tolerance, durability, and compatibility with high-current applications.
5. Advantages of Through Hole PCB Technology
Through hole PCBs offer several benefits:
- Stronger mechanical bonds—ideal for components that face physical stress.
- Easy prototyping and testing—simplifies breadboarding and circuit debugging.
- Better heat resistance—suitable for power electronics.
- Reliable solder joints—especially in automotive, aerospace, and military devices.
6. Limitations and Challenges of Through Hole PCBs
Despite their advantages, through hole PCBs have some limitations:
- Larger board size required due to component lead spacing.
- Slower manufacturing compared to SMT.
- Higher assembly costs for mass production.
- Not suitable for compact, lightweight designs like mobile devices.
7. Through Hole vs. Surface Mount Technology (SMT): A Detailed Comparison
| Feature | Through Hole PCB | Surface Mount Technology (SMT) |
| Component Size | Larger | Smaller |
| Mechanical Strength | Stronger | Weaker |
| Assembly Cost | Higher | Lower |
| Heat Resistance | Higher | Moderate |
| Automated Assembly | Less flexible | Highly flexible |
| Best Use Case | High-stress, power or test boards | High-density consumer electronics |
Conclusion: SMT is ideal for compact, high-volume designs, but through hole PCBs still win in durability and mechanical reliability.
8. Typical Applications of Through Hole PCBs in Modern Electronics
Common industries and devices that use through hole PCBs include:
- Automotive electronics (ignition coils, ECUs)
- Industrial machinery (relays, power drivers)
- Medical equipment
- Aerospace and defense
- High-power LED lighting
- Prototyping and educational kits
9. Through Hole PCB Manufacturing Process: Step-by-Step Guide
The manufacturing process includes:
- PCB design and layout
- Drilling of holes (plated through or non-plated)
- Copper plating (for multilayer boards)
- Component insertion
- Wave or selective soldering
- Inspection and quality control
Advanced through hole PCBs can have multilayer configurations and require precise alignment and hole registration.
10. Design Considerations for Through Hole PCBs
When designing a through hole PCB:
- Allow proper spacing for component leads
- Use correct hole sizes and tolerances
- Consider thermal reliefs for heat-sensitive components
- Design for wave soldering compatibility
- Mark polarity clearly for polarized components
CAD tools like Altium Designer, KiCad, and Eagle provide dedicated support for through hole layouts.
11. How Much Do Through Hole PCBs Cost in 2025?
In 2025, the price of a standard through hole PCB depends on several factors:
| Quantity | Layers | Price per Board (USD) |
| 10 pcs | 2 layers | $1.50 – $2.50 |
| 100 pcs | 2 layers | $0.60 – $1.20 |
| 500 pcs | 4 layers | $1.00 – $1.80 |
| Prototype | 2 layers | $20 – $50 (setup included) |
Other cost influencers:
- Drill count and hole size precision
- Board thickness and copper weight
- Solder mask color and surface finish (HASL, ENIG, etc.)
- Lead time and special requirements (RoHS, IPC Class 3)
12. Tips for Choosing a Reliable Through Hole PCB Manufacturer
To ensure high quality and consistent delivery:
- Look for IPC certifications (IPC-A-610, ISO 9001)
- Check experience in through hole production
- Ask for sample boards
- Confirm capabilities for double-sided soldering and wave soldering
- Evaluate customer support and engineering feedback
KingSunPCB is a trusted manufacturer specializing in through hole PCBs with over 15 years of experience. We offer low-cost prototyping and high-volume production with fast turnaround and strict quality control. Request a free quote today!
13. Conclusion: Is Through Hole the Right Choice for Your Project?
Through hole PCBs remain relevant in 2025 for projects where durability, mechanical stability, and ease of prototyping are essential. While SMT is preferred for compact, high-density boards, through hole technology is unbeatable in specific high-reliability applications. The key is understanding your project’s requirements and choosing the right manufacturing partner.
14. FAQs About Through Hole PCBs
Q1: Are through hole PCBs still used in modern electronics?
Yes, especially in automotive, aerospace, and industrial applications that demand durability.
Q2: Can through hole and SMT be used together?
Absolutely. Many PCBs use a hybrid approach to leverage the strengths of both technologies.
Q3: Is through hole more expensive than SMT?
Generally, yes—due to larger board space and manual assembly processes.
Q4: What’s the best way to reduce through hole PCB cost?
Optimize design for manufacturability, reduce hole count, and work with experienced suppliers like KingSunPCB.