Hot Bar Reflow Soldering

Hot Bar Reflow Soldering is a selective soldering process where two pre-fluxed, solder coated parts are heated with a heating element (called a thermode or a hot bar) to a sufficient temperature to melt the solder. After this the parts are cooled below the solidification temperature to form a permanent electro-mechanical bond.

Flex carriers and foil connectors

Mobile electronics such as telecommunications equipment, as well as the electronics in motor vehicles require increasing packing density and thus arrangement of the circuits in multiple layers. The connection of the layers are favorably produced with flexible circuit carriers and / or foil connectors. These connections are prepared, mostly by Hot Bar Reflow Soldering. For equipping electronic devices with digital displays, display drivers on flexible carriers can be used. The connection to the rigid circuit board can be produced by using thermode soldering too. Furthermore the method can be used to join flat cable and foil cable with rigid components like plug connectors and PCBs.

Process

For components that require a very precise positioning, Hot Bar Reflow Soldering is the most ideal process. Pulsed heated soldering differs from traditional soldering because 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. Because pressure is applied during the complete cycle, the process is very suitable for parts that could disconnect during cooling down. By using Hot Bar Reflow Soldering process multiple connections (up to > 100mm length) can be made simultaneously in a single process cycle. Making these connections simultaneously also prevents wires disconnecting while soldering the neighboring one.

Hot Bar Reflow Soldering Benefits

  • Fast temperature ramp-up and cool-down
  • Closed loop temperature control
  • Accurate positioning of the parts
  • Multiple connections can be made simultaneously
  • Cost effective due to elimination of third component such as connector

Applications Hot bar Reflow Soldering

  • connecting flex-foils to Printed Circuit boards
  • small wires
  • small coax cables
  • very light or small components.