Surface Mount Technology is the current vogue in electronics assembly. The printed circuit boards in your mobile phone and computer are likely to have been assembled using solder paste. The paste is stencil printed onto the bare board, components are carefully placed on the solder paste pads and the whole board is sent through a oven where the solder paste is reflowed to make lasting joints.

Printing solder paste has traditionally been a very wasteful process with some operations having to throw away up to 70% of the solder paste in order to maintain print quality. The paste has a tendency to "dry out" and even "crust" while on the stencil which has severe detrimental effects on the repeatability of the printing process.

Now Pastepuck Ltd has introduced a new, low cost pressurised printing system that reduces paste waste to virtually nil. It also improves the shape and definition of print deposits, cleans up the whole process and isolates operators from the potentially harmful, lead bearing, solder paste.

A further major benefit of the paste puck lies in its retrofitability. It can be fitted to virtually any make and model of stencil printer, enabling assemblers with a variety of printing machines to standardise on one print technology. It requires no auxiliary power and is not dependent on the printer's software in order to work.

With the new PastePuck costing in the region of £5000, the initial outlay in many instances can be recouped in a matter of months and thereafter, considerable material savings accrue.

The PastePuck is available in two print window sizes, 300mm and 380mm but each can be tailored to meet specific print pattern sizes with the use of Trim Tab Reducers that ensure optimum utilisation of the print medium.

Most solder pastes can be left in the PastePuck overnight with the Puck resting on the stencil, and will print easily the following morning, reducing the need for clean down and again reducing paste waste.

If required, the solder paste can be sealed within the Puck and the Puck removed from the machine for long-term storage under refrigeration if necessary.

The Pastepuck utilises the paste cassettes developed by Semco under license from DEK. Most pastes are available in this form of but cassettes can also be filled from conventional cartridges.