Hot-Bar Reflow Soldering

Pulsed-Heated Hot-Bar Reflow Soldering is a selective soldering process where two pre-fluxed, solder coated parts are heated to a temperature sufficient to cause the solder to melt, flow, and solidify, forming a permanent electro-mechanical bond between the parts and solder. Pulse heated soldering differs from the traditional soldering process in that the reflow of solder is accomplished using a heating element called a thermode which is heated and cooled down for each connection. Pressure is applied during the entire cycle including heating, reflow, and cooling. This technique is most commonly used to connect flexfoils to Printed Circuit Boards.

Process description

With HBR Soldering pressure is applied during the entire cycle, including heating, reflow and cooling. Because pressure is applied during the complete cycle, the process is very suitable for parts that would jump loose during cooling down when soldered with other techniques. Typical application examples are flexfoils, small wires, very light or small components, etc.


The position of the parts is very accurate because the pressure is applied during cooling down. For components that require a very precise positioning after being soldered HBR Soldering is the most ideal process.


With HBR Soldering all connections to be made simultaneously. Up to 200 leads or wires can be connected in one process cycle (typically around 15 seconds). Making the connections simultaneously also prevents one wire jumping loose while soldering the neighbouring one. Typical application examples are multiple small coax cables.


The power output of a good quality hot-bar is very high. A hot-bar as small as 10mm can generate up to 4000 Watt compared to maximum 50 Watt for a conventional solder iron and 30 Watt for diode laser soldering. This enables short process times and good solder results on parts with a high-energy requirement, like MC-PCB and ceramics.


HBR Soldering is a process that is reproducible, quantifiable, and traceable to quality standards like ISO / NIST. It is safe for the operator, highly operator independent and easy to automate.

And opposed to traditional soldering, pulse-heated soldering reflows solder by using a thermode that is heated and cooled down for each connection. This selective heating-up of just a small part of the components makes the process very suitable for soldering heat-sensitive parts. Typical application examples are CCD camera chips, connectors, etc.

Thermo-plane thermode & Quick Connect Block

Hot-Bar Reflow Soldering Process