Electronic Assembly UK

For the Electronic Assembly, the Surface Mount Devices (SMDs) and the solder pads are attached to the same side of the Printed Circuit Board. The pads can be on both sides of the PCB.

Pin-Through-Hole devices (PTH) are place on top side of the PCB, have their leads insert through holes in PCB, and are solder from bottom usually through a wave soldering process.

PCB circuit assemblies that use both types of components, SMD and PTH, require special handling because they each use different soldering techniques.

Surface Mount Devices uses reflow or wave soldering and it is important to attach them to the Printed Circuit Board.

• Solder Paste is apply to the Solder Pads to the PCB with a stencil
• The SMDs are apply with their leads on top of the Solder Paste
• The Surface Mount Device and Printed Circuit Board need to heat-up for the process
• Reflowing (melting) the solder, connects the leads of the components to the solder pads

• PCB is use for gluing the components.
• The Printed Circuit Board is turn over

Pin-Through-Hole devices, or Plated Through-hole Devices (PTH) must be wave solder

After the PTH components are insert into the holes of the PCB, and without turning the board over, the PCB is pass over the wave of solder, connecting the component leads to the printed circuit board.

When both SMT and pin-through-the-hole devices are use on the same electronic assembly, several steps needs to follow for soldering:

• On the “component side” of the PCB, the SMDs are place and reflow solder;
• The board is turn over and on the “solder side,without soldering them; the SMDs are then glue in place;
• The board is turn over again, and passing their leads through holes in PCB from “component side”, PTH components are machine insert;
• Now, special-handling components are insert into the PCB by hand;
• The “solder side” of PCB is wave solder, soldering SMDs glue to the “solder side” of PCB, leads of PTH components, and the leads of the special handling components, all in one step
• The board is test.

Before submitting the PCB for manufacturing, some design issues are of special concern and need attention:

• To allow maneuvering of the insertion machines, PTH devices require extra room on the PCB;
• When making decisions about assembly using lead-free techniques, the thermal profile issues affecting the soldering process should be addressed.

Rush PCB UK has both experience and expertise in all three types of assembly SMD, PTH, and mixture of both SMD and PTH. Regardless of your Printed Circuit Board needs our engineers can make your project a reality. So, contact us now for perfect Electronic assembly.

Let our engineers at RUSH PCB work with you on the engineering and design of your mixed component assemblies. Your project is important to trust it to anyone else.

For more information, contact us at sales@rushpcb.uk, or call us at 0203 750 0201