Flash testing of PCBs during the initial production stages

PCB manufacturers can take advantage of a fast, reliable and safe solution to meet the growing demand for flash/HIPOT tested (2 kV) unpopulated boards. Electrical safety testing specialist Clare has developed a bespoke system using its HAL104 instrument connected to a test enclosure, which enables the easy flash testing of PCBs during the initial production stages.

The enclosure has a conductive foam base with modular sections to accommodate different sizes of PCBs. It can have either a spring-mounted probe system or a further section of conductive foam can be added to allow it to work with different types of PCBs.

The move follows the increasing trend that all base PCBs must now be flash tested during the manufacturing process to ensure that they have no defects and are compliant with safety standards. This comes from growing demand among global component assemblers that all electronic components should be able to pass a flash test before final build.

Two types of PCB can be tested: those with one surface covered in metal and ‘standard’ units with an insulated side.

Regardless, the track side of the PCB is placed face down on the conductive foam, enabling all metallic parts to be in contact with the foam and providing a ‘base bed’ for the remainder of the insulating surface of the board. Once in position, a flash test is then performed across the board, testing for integrity.

Richard Williams, senior applications engineer - Clare, said the HAL-based solution will help to meet the growing requirement for flash-tested PCBs.

“Electronics manufacturers want to ensure that component parts are capable of withstanding the voltages that final assembled products will operate to.

“Some manufacturers in the UK and China have already adopted this approach for their PCBs, while others are expected to follow suit.”

The HAL104 from Clare is part of a range of digital instruments which can perform the complete suite of standard electrical safety tests and allows full traceability of test results and records via internal data memory storage. It combines the performance of a multifunction production line safety tester with load and power factor measurement for product energy consumption and ratings assessments. This versatile all-in-one tester has been specially designed for accurate electrical tests required by modern electronic manufacturing environments. As well as incorporating key functional checks, the instrument meets the end-of-line electrical safety compliance tests required by the majority of safety standards.

The tester has applications in the electronics manufacturing sector - particularly in those production situations where high-resolution performance measurements are important such as LED products in low-energy lighting applications and PV solar panels. As well as load and power functional tests, the tester incorporates AC/DC Hipot, insulation, ground bond testing to 40 A, load testing up to 20 A (5 kVA) with leakage measurements from 100 µA to 20 mA, with 10 µA resolution.