THT vs. SMT Pogo Pins: Which Mounting Technology Is Best for Your Application?

Choosing between through-hole technology (THT) and surface mount technology (SMT) for pogo pin applications makes a huge difference. This is in terms of your product’s reliability, manufacturing efficiency, and the total cost of ownership. THT components can give you mechanical strength ratings up to 50g shock resistance and 10g vibration tolerance. On the other hand, SMT offers component density improvements and automated assembly compatibility. Your choice depends completely on your needs. That could be current capacity, volume needs, and more.

The latest electronic devices need super reliable electrical connections. These must blend performance, cost, and manufacturing efficiency. Understanding what is THT and SMT mounting technologies helps engineers choose the best pogo pin solutions. This can be for testing equipment, charging systems, and so much more. Most of the time, these components are placed directly onto the surface of the PCB or through pre-drilled holes on the PCB.

Key Takeaways

• Through hole technology has better mechanical bonds with insertion forces of 50–200 grams and cycle life
• SMT allows automated assembly at speeds up to 50,000 components per hour
• Pin-in-paste soldering enables mixed-technology boards, blending both THT and SMT
• Environmental resistance prefers THT assemblies for applications requiring shock resistance above 25g and vibration tolerance exceeding 5g
• Production volume determines cost-effectiveness, with SMT technology break-even at around 10,000 units annually

What are THT and SMT Pogo Pin Technologies?

Through-hole technology is all about putting in component leads through holes drilled in the PCB. They are connected through wave soldering on the opposite side of the board. This creates really strong mechanical connections. Surface mount device (SMD) components, a lot like pogo pins, mount directly onto printed circuit board surface pads. It does this using reflow soldering processes. This means higher component density and automated assembly. Both electronics assembly techniques work for very specific application requirements. This is generally based on mechanical demands, electrical specifications, and manufacturing limitations.

THT Construction and Advanced Processes

Through-hole components represent the traditional mounting method where electronic component leads extend through pre-drilled holes in printed circuits. Recent developments include pin-in-paste soldering, where solder paste fills plated through holes before component insertion, allowing mixed SMT and THT assemblies to undergo single reflow processing.

SMT Assembly Classifications

Surface mounting eliminates the need for holes in the PCB by placing components like resistors and capacitors directly onto surface pads. The SMT process includes three main assembly types:

• Type I Assembly: SMDs only, single or double-sided placement
• Type II Assembly: Mixed SMD and THT components (most complex)
• Type III Assembly: Discrete SMDs on bottom, THT components on top

According to MarketsandMarkets, the global Surface Mount Technology (SMT) market is expected to grow from $5.8 billion in 2023 to $8.4 billion by 2028, with an annual growth rate of 7.8%.

Technology Development Timeline

SMT was initially developed in the 1960s as “planar mounting” but gained popularity in the 1980s, revolutionizing electronics manufacturing. THT preceded SMT by decades, serving as the foundation for early electronic assemblies before automated surface mounting emerged.

Future Technology Trends

Advanced packaging techniques including embedded components and 3D integration continue pushing miniaturization limits. Pin-in-paste soldering adoption increases for hybrid assemblies, while automated inspection systems improve quality control for both mounting technologies in high-reliability applications.

How do SMT Vs THT Pogo Pins Differ in Mechanical Performance?

THT mounting delivers superior mechanical strength with insertion force ratings typically ranging from 50-200 grams and extraction forces up to 150 grams, while SMT variants provide insertion forces of 30–150 grams with reduced lateral strength tolerance compared to THT. Mechanical cycle life for THT connections exceeds 100,000 insertion cycles under standard conditions, compared to SMT designs rated for 50,000-75,000 cycles.

Component Lead Configurations

THT assemblies utilize two primary lead types: axial lead components where leads exit both ends of the component body, and radial lead components where leads emerge from one side. Axial configurations provide flatter board profiles, while radial designs occupy less surface area for higher density applications.

Environmental Stress Resistance

THT Vs SMT: Which Technology offers Better Electrical Performance Characteristics?

Surface mount components provide superior electrical performance with lower parasitic inductance and capacitance due to shorter connection paths, enabling better signal integrity at frequencies above 1 GHz. Contact resistance values for both assembly technology methods typically range from 10 to 50 milliohms, but SMD designs achieve more consistent resistance due to controlled solder joint formation during reflow soldering processes.

Electrical Performance Metrics

High-frequency applications benefit from SMT’s reduced parasitic effects, while power applications may favor THT’s thermal advantages. The difference between SMT and THT becomes significant in RF circuits, where signal integrity determines system performance. Both soldering techniques provide reliable electrical connections when properly implemented according to industry standards.

Performance Comparison:

• SMT parasitic inductance: 0.5-1.5 nH
• THT parasitic inductance: 1.5-3.0 nH
• Current capacity: 1-5A (both technologies)
• Contact resistance: 10–50 milliohms

What are the Manufacturing and Assembly Differences?

SMT assemblies utilize automated pick-and-place machines operating at speeds up to 50,000 components per hour, followed by reflow in controlled atmosphere ovens at 240-270 °C for lead-free processes. THT assembly requires component insertion through pre-drilled holes, followed by wave soldering or selective soldering operations at 250-260 °C, with longer processing times compared to SMT.

SMT Assembly Process

The advent of surface mount technology revolutionized electronics manufacturing by enabling automated production with high precision and repeatability. SMT offers significant advantages in production speed and component density, making it the preferred choice for modern electronics. Specialized equipment is used to place components directly onto the surface. This ensures consistent placement accuracy.

THT Assembly Process

Traditional through-hole technology involves a more manual approach but provides superior mechanical reliability for demanding applications. THT requires the drilling of holes in the printed circuit board, which adds processing time but creates stronger mechanical bonds than SMT. Selective soldering targets specific areas, while wave soldering processes entire assemblies simultaneously.

Advanced Soldering Techniques

Pin-in-paste soldering represents a significant advancement, allowing THT components to be processed through SMT reflow ovens by filling plated through holes with solder paste before insertion. This innovation enables mixed-technology assemblies with simplified manufacturing processes.

How do Cost Factors Compare Between THT and SMT Approaches?

SMT doesn’t require PCB drilling operations, reducing manufacturing costs by 20-30% for high-volume production through automated assembly processes. THT offers lower setup costs for prototyping and small-batch production, while SMT components are typically priced 10-15% lower than equivalent through-hole components due to smaller package sizes and standardized manufacturing.

Production Volume Economics

Production volume determines the most cost-effective approach, with the adoption of SMT becoming advantageous at higher volumes due to automation benefits and reduced labor requirements.

Which Applications Benefit Most from Each Technology?

SMT components can be placed in consumer electronics, portable devices, and high-density applications where space constraints and automated assembly requirements drive design decisions. THT implementations serve industrial equipment, test fixtures, and automotive applications requiring mechanical robustness and reliable electrical connections under harsh environmental conditions using THT for maximum reliability.

Application-Specific Recommendations

Different industries have varying requirements that favor one technology over another based on performance, reliability, and cost considerations. The age of SMT has brought significant advantages to consumer electronics, while THT remains crucial for industrial and military applications where components can be placed under extreme mechanical stress.

SMT Optimal Applications:

• Consumer electronics requiring miniaturization
• High-frequency circuits above 1 GHz
• Automated production environments
• BGAs and fine-pitch components

THT Optimal Applications:

• Industrial test fixtures requiring durability
• High-power applications with thermal management needs
• Military and aerospace equipment
• Applications requiring enhanced testability

Mixed-Technology Approaches

Two PCB assembly methods can be combined on SMT boards to optimize performance, with high-frequency signals using SMT and power connections using THT for mechanical strength. Pin-in-paste soldering enables these hybrid approaches through unified reflow processing.

What Quality Standards and Testing Apply to Each Technology?

Both THT and SMT pogo pin assemblies must comply with IPC-A-610 Class 2 or Class 3 standards for acceptable workmanship, with Class 3 requirements applicable to high-reliability applications. Environmental testing according to ASTM G99 and ASTM G133 standards evaluates performance under temperature cycling, humidity exposure, and mechanical shock conditions for both assembly technologies.

Compliance Standards

Industry standards ensure consistent quality and reliability across different manufacturing facilities and applications. These standards define acceptable criteria for both THT and surface mount assemblies, providing clear guidelines for manufacturers implementing either assembly technology.

Key Standards:

• IPC-A-610: Electronic assembly acceptability
• ASTM G99: Tribological testing procedures
• ASTM G133: Wear resistance evaluation
• DIN 50324: Material testing protocols

Reliability Testing Procedures

Comprehensive testing protocols validate long-term performance under operational conditions for both THT and SMT assemblies. These procedures ensure components meet specified performance criteria throughout their operational lifetime. Popcorning represents a critical failure mode in SMT, where moisture absorption causes component cracking during reflow soldering.

Testing Requirements:

• Vibration testing: 10-2000, Hz frequency range
• Shock testing: 1500g acceleration levels
• Thermal cycling: -40 °C to +85 °C temperature range
• Humidity exposure: 85 °C/85% RH conditions

How Should Engineers Select Between THT and SMT for Specific Applications?

Application selection criteria include mechanical stress requirements, electrical performance specifications, production volume targets, and environmental operating conditions, with THT preferred for applications exceeding 25g shock or 5g vibration levels. SMT selection suits applications requiring component densities above 100 components per square inch, automated assembly compatibility, or cost optimization for volumes exceeding 10,000 units annually.

Selection Decision Matrix

The PCB assembly process selection requires careful evaluation of multiple factors including performance requirements, production constraints, and cost considerations. Engineers must balance the advantages and disadvantages of SMT against THT requirements for their specific application.

Choose THT When:

• Mechanical stress >25g shock or >5g vibration
• Enhanced testability required (test probe access)
• Environmental sealing is critical
• Component replacement needed in field service

Choose SMT When:

Space constraints and high-volume production requirements typically favor surface mount technology for modern electronics applications. SMT means higher component density and automated assembly capability, making it ideal for consumer electronics and portable devices. The smaller components used in SMT enable miniaturization while maintaining electrical performance and reliability standards.

• High-frequency performance >1 GHz required
• Automated assembly available
• Production volume >10,000 units annually
• BGAs or fine-pitch components needed

Ready to Optimize Your Pogo Pin Connectivity Solution?

The choice between THT and SMT mounting technologies impacts your product’s performance, reliability, and manufacturing efficiency. Promax Pogo Pin’s engineering team provides technical consultation to help you select the optimal mounting approach for your specific application requirements.

Contact our experts today for personalized recommendations based on your mechanical, electrical, and production needs. Our comprehensive pogo pin solutions deliver the performance and reliability your applications demand, backed by rigorous quality standards and proven manufacturing expertise.

THT Vs SMT FAQs

How does pin-in-paste soldering enable mixed THT and SMT assemblies?

Pin-in-paste soldering fills plated through holes with solder paste before THT component insertion, allowing both SMT and THT components to be processed in a single reflow oven cycle. This advanced technique eliminates the need for separate wave soldering operations, reducing manufacturing complexity and improving quality consistency. The process requires precise solder paste volume control and compatible component lead geometries.

What causes popcorning in SMT components, and how can it be prevented?

Popcorning occurs when moisture-absorbed SMT components rapidly heat during reflow soldering, causing internal steam pressure that cracks the component package. Prevention requires proper component storage in moisture-barrier bags with desiccants, baking components before assembly if moisture limits are exceeded, and maintaining controlled humidity environments during assembly. Components with higher moisture sensitivity levels require more stringent handling procedures.

Why do THT assemblies provide better testability than SMT designs?

THT component leads extend through the PCB, creating accessible test points on the bottom side for in-circuit testing and debugging. Test probes can easily contact these leads without specialized fixtures, enabling efficient troubleshooting and quality verification. SMT assemblies require dedicated test points or specialized fixtures for probe access, increasing testing complexity and potentially adding cost to the assembly process.

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