New laboratory-sized reverse plating unit

Citation

(1999), "New laboratory-sized reverse plating unit", Circuit World, Vol. 25 No. 1. https://doi.org/10.1108/cw.1999.21725aad.011

New laboratory-sized reverse plating unit

New laboratory-sized reverse plating unit

Keywords Chemring, Plating

A compact, laboratory-sized reverse pulse plating unit has been developed by Chemring Plating Systems. Called the CPS 60, this unit provides 10 amps forward and 50 amps reverse current and is designed to be used for small batch PCB production and for laboratory or manufacturing tests.

Ideal for use in PCB product development, the CPS 60 produces exactly the same manufacturing results as Chemring's full size reverse pulse plating units. These are available in 200 amp increments, with the largest being the CPS 4800. This single output unit provides a forward current of 1,200 amps with a reverse pulsed current of up to 3,600 amps.

Chemring Plating Systems' reverse pulse technology enables PCB manufacturers to produce the higher quality boards when used in conjunction with "pulse compatible" electrolyte. Typically this enables 1:1 hole to surface copper distribution at current densities of between 30-40 asf (3.0-4.0 amps per sq. decimetre), which can increase a plant's productivity by some 30-50 per cent.

Using reverse plating technology, the CPS 4800 replaces the traditional DC rectifier. During the reverse pulse, brightener in the electrolyte is desorbed from the surface areas closest to the anode. These are the high-current density areas on the board's surface. This temporarily increases the resistance in these areas and causes the plating current to redistribute towards the low current density areas, which are the holes. In this way, the plating rate increases in the holes until the brightener is re-adsorbed and the next reverse pulse repeats the process.

The advantage of Chemring's reverse pulse plating system is that the redistribution of copper can be achieved without having to lower the current density, which is especially important when working on high-quality and complicated board layouts. PCBs manufactured using a reverse pulse plating system achieve 1:1 or better hole to surface distribution without a large build-up of copper on exposed, fine line tracks.

The CPS 60 reverse plating unit can also be used for gold tab plating and other specialised PCB applications. The CPS 60 unit, as with all the CPS range, integrates with Chemring plating systems "Multicom" control system, which enables equipment to be installed on any new or existing plating line.

For further information contact: Graham Benton, Chemring Plating Systems. Tel: +44 (0) 1705 735457; Fax: +44 (0) 1705 817509.