Contax helps MRP electronics eliminate micro-cracking
Contax helps MRP electronics eliminate micro-cracking
Keywords: Printed circuits, Assembly
MRP Electronics Plc, one of the UKs leading contract electronics manufacturers specialising in surface mount PCB assembly has just purchased three McDry cabinets of varying sizes from production automation specialist,Contax Ltd.
MRP Electronics manufactures a wide range of PCB assemblies, many fitted with BGA and QFP devices, and required an effective storage medium to ensure integrity of the product at varying stages of manufacture. The small cabinet will be used for local storage, whilst the medium one will house SMD devices during production, with the largest unit used for permanent component storage.
Explained John Cardi, Production Engineering Manager at MRP Electronics,“The storage of moisture- sensitive devices is critical. When the BGAs are stored in an open enviroment they absorb moisture which can give unpredictable results during reflow. If they are stored in Moisture Barrier Bags (MBBs), once they are removed they have to be used quickly or rebagged.
We have experienced some problems with popcorning during reflow, where the soldered heat drives out any remaining moisture so the devices crack. This is obviously a waste of both components and test/rework capacity, so we needed to resolve the issue”, he said.
The incidence of micro-cracking is widespread and has been highlighted in the standard for “Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface Mount Devices”, IPC/JEDEC J-STD-033a (July 2002).
It is estimated that virtually 100 per cent of IC packages containing moisture experience a problem during the reflow process. This results in the corrosion of printed circuits and can cause wiring breakage and many other problems.
MRP Electronics decided that they needed to store the SMDs in a humidity controlled environment to ensure their integrity and prevent a “use by”date. The company looked at two leading manufacturers offerings, and after full evaluation decided upon the McDry cabinets from Contax.
McDry cabinets are nitrogen-free, instead relying on a powerful zeolite desiccant which is self regenerating and therefore, does not need replacing. This ensures that the units save both maintenance time and the associated costs. Furthermore, the cabinets vary in both size and humidity level, going as low as 1 per cent humidity.
For further information, visit the web site: www.contax.com
