1. Automated THT: selective & wave
Wave and selective soldering subject a PCBA to significant thermal activity, requiring strict parameter management. Improperly calculated parameters cause thermal shock to SMT components or result in insufficient solder on THT joints.
This chapter defines wave dynamics, flux application, and preheating profiles. It specifies machine setups required to achieve reliable barrel fill while minimizing bridging, icicles, and excessive dross generation.
- 1.1 THT-friendly design
Through-Hole Technology (THT) remains valuable for providing mechanical stability (such as for heavy connectors or relays), accommodating high-power components, and creating joints that benefit from superior mechanical strength compared to surface mo...
- 1.2 Fluxing & preheat control
Through-hole soldering is fundamentally a thermal process. The carefully controlled combination of fluxing and preheating serves two key purposes: it chemically cleans the metal surfaces and protects the components from thermal shock. This stage prep...
- 1.3 Selective solder programming
When assembling a mixed-technology board—where sensitive SMT components are located near THT pins on the same side—wave soldering the entire assembly is not feasible, as it would cause thermal damage to the SMT parts. Selective soldering provides the...
- 1.4 Wave solder setup
Wave soldering is a traditional and robust mass production technique. Its effectiveness relies on the careful alignment of mechanical and thermal parameters. Establishing a stable baseline setup is key to a repeatable process. This involves controlli...
- 1.5 Common defects & corrections
When you encounter defects like solder balls, non-fills, or bridging, it's important to systematically review the entire process before concluding the issue is with the solder wave itself. Often, these defects are strongly linked to upstream preparat...