ICT Seminar
"Horizontal versus Vertical"at Shipley, Europe Ltd. Coventry7 February 2002
Keywords: ICT, Seminars
Chris Wall, the newly appointed Vice Chairman of the ICT welcomed everyone,thanked the generous hosts, Shipley Europe Ltd and opened the meeting, which was well attended by over 25 delegates. Because of the popularity of this topic, the event is being held again at another location, Arundel in Sussex on May 14th for a different audience drawn largely from the south coast.
The first paper by Dr John Graves of Shipley was a thorough overview in generic form of the advantages and disadvantages of the two processing techniques. The hour paper seemed to fly by because it was so well presented. Whilst vertical processing is still the predominant method employed in the industry for metallising printed circuit boards, there is a growing take up for horizontal techniques. New developments in chemical formulations and innovative fluid delivery designs have made it possible for solution dwell times to be shortened making horizontal metallisation a more attractive proposition. Electroless copper and "direct plate" products lend themselves to horizontal processing and with the development of conveyorised electroplate modules an increasing volume of boards are being metallised horizontally.
Horizontal methods have grown in popularity and most of the processing stages of printed circuit board manufacture such as resist coating, development,etching, stripping, cleaning, brushing, oxidation, metallisation and solderable finishes can now be applied using a conveyorised system. John then enlarged on the gains to be had for horizontal techniques from the angles of environmental awareness, productivity, handling, flexibility, fluid dynamics and the cost of maintenance. Water and energy consumption are higher with vertical methods. Horizontal is more operator-friendly from a chemical hazard viewpoint. Horizontal also scores on productivity and work in progress is less. Thin materials are more easily handled in horizontal processing but vertical has more flexibility. Maintenance and cost are higher for horizontal and the equipment cost is much greater. High technology work containing advanced microvias struggles with vertical processing unless vibration is used. Vertical conveyorised technology, a hybrid of vertical and horizontal processing equipment, is also commercially available. The use of innovative fluid delivery systems in horizontal modules ensures excellent solution exchange in and out of microvias. The advantages of horizontal processing are establishing the technology as the preferred process for micro-via metallisation. Recent announcements in trade journals also suggest that horizontal electrolytic pattern plate equipment is very close to commercialisation, another leap forward for horizontal equipment.
Bruce Norsewothy of Process Automation Ltd gave the next paper entitled"Vertical versus Horizontal Plating Technology". This comprehensive paper covered, in copious detail the features and developments of modern equipment for the two technologies. The drivers are cost and technology but for the printed circuit board manufacturer the choice depends on current and future product mix and of course the budget available. Horizontal equipment is undoubtedly more expensive but some work demands the use of that technique. Bruce then began the description of the many benefits of the PAL horizontal and vertical plating equipment, which has been evolved in recent times. Many patents have been created from the careful development work involved to optimise the equipment for the advantage of the customer base. Thus he expounded on the gains from the following: Anode diaphragms, Copper replenishment systems, eductors, E Track, floating shields, Push rod, gripping floating shields, independent control systems, inert anodes, new bottom shielding systems, optimised rinsing systems, flight bar vibration systems, stripless top racks, periodic reverse pulse plating especially for high aspect ratios. Clearly there has been an enormous amount of liaison with the customer base to take on board all these diligently prepared improvements. There was a clear formula for meeting customer demands and maintenance was user-friendly. This was a thorough insight into the equipment evolution cycle for the gain of the customers. Very refreshing.
Chris Wall invited questions and there were several before he closed the meeting and invited the delegates to indulge in the generous buffet provided by Shipley. Overall, this was a very informative evening.
Frank CoultardPCIF/FEI
