SMT soldering

Surface mounting components (surface mount device – SMD) are soldered directly onto the top or bottom of the PCB by means of solderable contact surfaces. Since the components do not have to have wire connections that are routed through drill holes into the PCB and soldered, surface mounting (surface mounting technology – SMT) supports high-density assembly and the use of both sides of the PCB.

Your advantages

  • Reproducible high process quality, thanks to the high degree of automation
  • High assembly density: surface mounting allows both sides of the PCB to be used
  • High process efficiency, thanks to processing THR and SMD components using one method


Surface mounting PCB terminal blocks  

SMT-compatible PCB terminal blocks on the connection surfaces

Before the surface mounting components are assembled, the relevant metal-plated pads on the PCB are printed with solder paste by means of screen, stencil or dispenser printing.

The components are then assembled and the entire module is soldered. The reflow method has become established for the top of a PCB. SMD components on the bottom of a PCB are often adhered and soldered in a wave soldering or dip soldering bath.

Compared to through-hole components, SMD components are characterized by low holding forces on the PCB, which usually means that the soldering spots may not be subjected to high mechanical loads. Nevertheless, in order to ensure a secure hold on the PCB, many SMD components have anchor metal on the side.

THR solder anchors are used where mechanical loads comparable to those for through-hole components are present. Consequently, corresponding components benefit from the process advantages of both technologies – SMD and THR. Phoenix Contact therefore uses this as a basis for new product innovations.

Find the right solution for you in no time at all

All PCB connections for SMT soldering can be found via the link below.


C6 The Exchange
Calmount Park
Dublin 12
D12 XE18