50% cost saving to the PCB industry

Printed Circuit Boards (PCBs) form the skeleton of so many electrical and electronic devices that we use in our everyday lives

Printed Circuit Boards (PCBs) form the skeleton of so many electrical and electronic devices that we use in our everyday lives.

What is often overlooked is that the manufacture of these high tech components relies heavily on the use of water.

It is estimated that in order to process one square metre of PCB, an astonishing 1.5 cubic metres of water is consumed and ultimately must be disposed of into the effluent chain.

In the UK alone, manufacturers use over 12 million cubic metres of water, each year and an estimated cost to the industry of GBP13 million.

Whilst the use of water is necessary in the manufacturing process, there are methods by which the consumption may be dramatically reduced, with the consequential benefits of cost saving being noticed at an early stage in the redefinition of the process chain.

"Drag Out" is the term commonly applied to the solution that remains on the boards as they are removed from the manufacturing process and before they are transferred to the cleaning and rinsing stages.

By increasing the temperature of the solutions in which the boards are treated, the viscosity and surface tension falls, thereby reducing the amount of "Drag Out" and, in turn, lessening the amounts of water required for rinsing.

The aim of the rinsing, itself, is to achieve fast and efficient "Drag Out" from the PCBs.

The increased efficiency in this process may be achieved by a number of methods such as optimising the design of rinsing tanks, improving the control of rinse water or using alternative configurations, such as multiple tanks, which optimises the use of water.

Whilst process re-structuring will be of benefit, the main challenges concerning the inflow of clean water and the outflow of polluted water remain key to cost reduction.

A survey carried out by the UK environmental group, Envirowise, indicated that the re-circulation of rinse water, purified by ion exchange, has reduced rinse water usage by some 70%.

As UK and European water directives and regulations concentrate on the levels of pollutants that industry is permitted to return to the water supply chain, there is an increasing need for businesses from all sectors to address ways by which cost saving and a responsible attitude to environmental matters can be addressed.

The UK PCB manufacturing industry has already demonstrated its ability to review its procedures and benefit from the findings.

Other industries must now follow suit.

For solutions on how to reduce costs with the use of water within industry visit the free seminars at IWEX 2003, 11th-13th November, NEC, Birmingham.

Back to top