Through-Hole Mounting

Through-hole mounting is the assembly method where component leads are inserted through PCB holes and soldered on the opposite side - it remains important for mechanically demanding or high-power electronic assemblies.

What Is Through-hole mounting?

• Definition: Leads pass through plated holes and are soldered to form structural and electrical joints.
• Process Modes: Commonly uses wave soldering, selective soldering, or manual solder operations.
• Mechanical Strength: Through-hole joints generally provide stronger anchoring than SMT-only joints.
• Design Implication: Requires drilled holes and dedicated keep-out planning in PCB layout.

Why Through-hole mounting Matters

• Durability: Preferred in connectors, transformers, and high-stress components.
• Power Handling: Larger lead and joint volumes can support higher current paths.
• Serviceability: Well-suited for repair-oriented and long-lifecycle industrial products.
• Density Tradeoff: Consumes board area and routing layers compared with pure SMT design.
• Process Integration: Mixed-technology boards need careful sequencing with SMT steps.

How It Is Used in Practice

• Hole Quality: Control drill, plating, and annular ring quality for reliable barrel fill.
• Solder Profile: Optimize wave or selective solder parameters by lead mass and board thickness.
• Mixed-Flow Planning: Define clear SMT-to-TH sequence and thermal exposure limits.

Through-hole mounting is a robust assembly approach for mechanically and electrically demanding components - through-hole mounting remains valuable when mechanical retention and power robustness outweigh density constraints.