Jason, The requirement of this Preheating technique is dependent on the level of quality desired. I have instructed many companies throughout the world and have received many questions regarding this process. The concern is that of thermal expansion within the capacitor. This too sudden expansion can cause the component to crack internally and thus is not visually detectable. This crack may also not be sufficient at time of installation to be be located as a fault during testing. But with thermal cycles from normal operation, this crack may propagate into a failure. This possibility of cracking while in the field is what should determine the need for installation utilizing preheat. It can happen. And if so, is this acceptable? Many companies do not feel this preheating is necessary. But I must report I have had contact with customers having difficulties with capacitor failure and once the preheating process is established, for some reason, the failure rates greatly decrease. And I know you will receive feedback many companies do not preheat and have no problems at all. This preheating procedure was brought to the industry attention many years ago through various articles and evaluation reports from component manufactures, consultants and industry periodicals. While the information within this literature is still valid, it should be noted the component manufacturing today has greatly improved from when this component cracking started. But still today the component manufactures normally state the manual soldering operation should duplicate the manufacturing process. In doing this, the manufacture provides a ramp rate which is recommended for proper installation. You also stated there seems to be no problem if the "operators take care". If you have operators who ALWAYS take care in every installation, you should be commended. But if one does not, how can this be determined and is the lack of the preheating process worth a possible a field failure? Marshall Canaday Applications Engineer / Training Specialist Pace Inc. [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************