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.