Re: Cracking Capacitors I am very interested in cracking in ceramic capacitors - particularly in switched mode power supplies (SMPS) - there is a need for large area capacitors which are now appearing in leaded formats - the leaded format would appear to be about 3 times the cost of leadless versions - hence the question - what is the maximum size of leadless ceramic capacitor which can be used with various circuit board materials which will not result in stress cracking during the lifetime of the product. This can be up to 10 years. This aspect of the problem is not concerned with cracking due to assembly processes - the concern is to do with long term stress cracking due to TCE mismatch between the ceramic capacitor and the substrtae material - this could be ceramic, FR4 or aluminium-core such as Berquist. I have failed to find any information on this aspect of the problem. Any assistance would be apriacted. Cian O Mathuna. ________________________________________________________________________________________________ Dr. Sean Cian O Mathuna Applications Director/Centre Manager Power Electronics Ireland, National Microelectronics Research Centre, University College, Cork, Ireland. Tel: International + 353 21 904016 Fax: Internatioanl + 353 21 270271 E-mail: [log in to unmask]