Skip to content
ELKAR
Electronic Board Repair

What Are Reflow Soldering and the Thermal Profile?

The four thermal zones of the reflow method used to solder SMD components and why the correct profile matters.

4 min readUpdated: 2026-07-05

Reflow soldering melts solder paste along a controlled temperature curve to bond the component to the board. The profile has four zones.

Preheat
Gradual ramp, prevents shock
Soak
Flux activation, thermal balance
Reflow (peak)
Solder melts, joint forms
Cooling
Controlled solidification
Thermal profile zones
A wrong profile causes cold joints, bridging or component damage. The profile must be optimized per board/component.

Related Topics

What Is BGA Rework?The process of removing and re-soldering BGA (Ball…What Is ESD (Electrostatic Discharge) Protection?How the invisible threat of ESD damages electronic…

Facing the same issue?

Send your faulty board to our lab or consult our expert team. Free pre-analysis.

Ask on WhatsAppGet a QuoteSend a BoardAsk Our Expert

+90 543 855 16 44 · info@elkarotomasyon.com