Reflow
Reflow is a process in PCB manufacturing that uses heat to melt solder paste and create permanent solder joints for surface-mount components.
What is Reflow Soldering?
Reflow soldering, also known as reflow, is a soldering technique used in Surface Mount Technology (SMT) to attach electronic components to printed circuit boards. It utilizes hot airflow to melt and reflow solder paste at high temperatures, forming good solder joints.
Paramax 15NZ12 BTU oven is a recirculation impingement, convection reflow soldering system for SMT process. Oven precisely heats and melts solder paste, bonding surface-mount components onto printed circuit boards with uniform temperature control and high production efficiency.
Heated Zone: 12 TOP / 12 Bottom
Conveyor Width: 2-18 In
Atmosphere: Air/ Nitrogen
What is Reflow Soldering?
Reflow Soldering is a PCB assembly process used in SMT (Surface Mount Technology) where electronic components are soldered onto a PCB by melting solder paste using controlled heat. It is the most common method used to assemble SMD components like BGA, QFN, resistors, capacitors, ICs, and more.
Solder Paste Printing
A solder paste (mixture of solder alloy + flux) is printed on PCB pads using a stencil for accurate paste deposition.
Component Placement
A high-speed pick-and-place machine places SMD components precisely on the solder paste for stable alignment.
Heating in Reflow Oven
The PCB passes through a reflow oven and follows a controlled temperature profile:
- Preheat Zone – slow heating to reduce thermal shock
- Soak Zone – flux activation & uniform temperature stabilization
- Reflow Zone – solder melts and forms reliable joints
- Cooling Zone – solder solidifies to ensure mechanical strength
Solder Joint Formation
When solder paste melts, it creates strong electrical and mechanical connections between component leads and PCB pads.
Types of Reflow Soldering
Convection Reflow (Hot Air)
Uses heated air circulation to melt solder paste through controlled airflow.
Infrared Reflow
Uses IR radiation for heating and solder melting during the thermal profile.
Vapor Phase Reflow
Uses hot vapor (Galden fluid vapor) for uniform heating and ultra-low voiding performance.