Vapour Phase Reflow Oven Commissioned

Zen Production Ltd. have now fully commissioned and installed our vapour phase SMD reflow oven. Since first trialling such an oven in October 2015, Zen kindly loaned SPS their demonstration oven until the model we had selected was available. We have now swapped over to using this and are looking forward to the same high quality results.

SPS Utilises Rapid Prototyping Controls Again

SPS is making great use of its general purpose power conversion controls platform again. This was initially developed as part of a Technology Strategy Board (now Innovate UK) part-funded project in 2009 – with TSB funding this meant the IP was retained by SPS. The controls platform was developed to allow rapid prototyping of systems for customers in the initial proof of concept phase. For the TSB project it allowed SPS to implement a very specific motor control hybrid vehicle requirement. The platform has been invaluable on numerous projects allowing us to use existing building blocks to rapidly prove out initial concepts to customers with low risk and cost. Once the concept is proven, a lower cost targeted implementation can then be developed. The current use is on a 50kW compact static power conversion application.

We are already in the process of revamping this controls platform to take advantage of the latest generation of microcontrollers and to also incorporate additional robustness and flexibility so that it can be used in lower volume niche applications for the manufacturing side of the business. We hope to be able to report on that progress in Q2 16 and publish a full specification.

SPS Trials Second SMD Reflow Oven

SPS is trialling an Asscon VP450 small batch vapour phase oven kindly provided by Zen Production Equipment Ltd. ( We were very impressed by the professional and open approach of Zen both in terms of sales and on-site commissioning support. The very first PCB trialled with the unit was a complex design incorporating significant copper floods with larger SMD components as well as other areas with just signal electronics. Our experienced production technician was very impressed with the excellent quality solder joints that were immediately evident and the simple operation of the machine. As a result of this initial trial and other subsequent successful uses of the machine, the decision was made to go ahead and purchase.

Review of in-house SMD Soldering

Having our own internal capability for high quality assembly of SMD PCBs for prototyping and small manufacturing batch runs has always been essential to meet customer lead times. Without a large multi-zone heater reflow oven and the possibility of tweaking parameters to optimise production yield, this is not a straightforward task. This has been compounded by the move to lead-free soldering and the same PCB having a large range of size and weight of components and tracking / flooding. Historically a modest size convection reflow oven has been used by SPS but it was apparent that a higher performance oven would be required for future use. An internal review of different reflow technologies was carried out by our production department and advice sought from various suppliers. After poor results from trialling a popular oven specifically designed for low volume / batch work, advice was sought from Electronics Yorkshire. They recommended using vapour phase technology which SPS was familiar with as a technology as it has been used for many years for soldering copper base plates to the underside of the DBC in isolated power modules.

New Member of the Team

As a result of a significant increase in both manufacturing and development work, SPS has taken on another full time engineer. Kyriakos Papameletis (Kyri) recently completed his Master’s degree at Leeds University in “Electrical Engineering and Renewable Energy Systems”. He will be assisting with supporting test and debug work in manufacturing as well as development work on the design side of the business. This means that we now have 7 Engineers on the development side of the business who all studied at Leeds University and between us we have 3 PhD.s, 3 Masters and 5 Bachelor Degrees!! Two of us are also Chartered Engineers – the equivalent of P.E for our North American colleagues.

Equipment Update

After a 1 month trial, SPS has gone ahead with purchasing a combined frequency response and wide bandwidth impedance analyser (PSM1735 + IAI fixture) manufactured by UK company Newton’s 4th Limited. Having access to this piece of equipment will allow more accurate and reliable characterisation of the frequency response of the significant range of complex control systems that SPS develops.

The previous piece of equipment SPS used for this was limited in its ability and was reaching the end of its life. The Impedance Analysis Interface module will also assist SPS with assessing the performance of both standard and custom designed components all the way up to 35 MHz which is an essential part of switched-mode power conversion and Electromagnetic Compatibility development work.