Hot Bar Soldering Design Rules

Design tips for successful hot bar reflow.

Hot bar soldering design rules.

Most pcb materials like fr2 and fr4 are very resilient to the application of heat during the hot bar reflow soldering or hot bar bonding process. Hot bar reflow soldering systems. 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. Hot bar reflow soldering is a selective soldering process where two pre fluxed solder coated parts are heated using a heating element called a thermode or a hot bar to a sufficient temperature to melt the solder.

Flex and pcb designs 1109 08 2010. Although normal solder will melt at 180 c ideal solder temperature is above 220 c to get a good flowing and wetting behavior but below 280 c to prevent burning of the solder. But some materials ceramic substrates in particular need to be heated in a more controlled fashion to minimize the chance of cracking. Solder must be pre tinned on pcb prior to hot bar process start point for screen printing is a 150 microns thick stencil with a mask opening that results in a 40 pad coverage for small pitch applications it is recommended to pre tin the parts by electro plating as being the most accurate technology.

The parts are then cooled below the solidification temperature to form a permanent electro mechanical bond. The temperature of the stamp transfers the required heat into the joint to be soldered. Design tips for successful hot bar reflow soldering. The connection of the layers are favorably produced with flexible circuit carriers and or foil connectors these connections are prepared mostly by hot b ar reflow soldering.

Flex carriers and foil connectors. Excessive differences in the heat continue reading pcbs. The hot bar must be set higher due to the thermal transfer losses. 3 layouts for hot bar reflow soldering.

Hot bar soldering in this method resistance soldering a heated stamp also cal led bar or thermode is pressing with an adjustable programmable force on the two parts to be joined one lying on top of the other.