PCB technology handles high currents on densely populated boards

August 28, 2013 // By Christoph Hammerschmidt
A challenge in modern high power circuit boards is combining high current and control electronics into an extremely limited space. A solution is the partial thick copper technology called Wirelaid. Besides a reduction in cost, a reduced number of layers, improved heat dissipation and reduced system volume can be achieved; PCB manufacturer Würth Elektronik designs to specific customer requirements for bespoke solutions.

According to Würth, the partial thick copper technology has shown good results, when high current is required on some parts of the PCB and complex control electronics in other parts. A compact PCB must safely carry high currents and as many fine pitch tracks as possible.
 With the Wirelaid technology, designers can increase the copper cross section at certain points while maintaining a low layer count for the board. This reduces the volume and can simultaneously meet the current and heat dissipation requirements.

Wirelaid production is relatively straightforward: Silver plated copper wires are fixed onto a copper foil using welding points and then pressed using standard production processes together with the printed circuit board substrate.

Würth Elektronik has created a Wirelaid design guide for customers explaining the spacing and dimensions that should be used. The design guide also contains an overview of the current carrying capacity of the different wire sizes. The company is currently working with 1.4 mm and 0.8 mm thick copper wires that are embedded either on the outer or inner layers of the board. The partial thick copper technology can be used in many high-current applications, from drive technology to engine electronics and inverters.

Würth Elektronik; www.we-online.com