Hi there folks, can I get some experience on the best component placement & orientation directions for when designing an SMT board for use with a convection reflow oven to design for minimum defects. All orientations in relation to the direction of flow through the oven. 1) Electrolytic capacitors. Should these be placed so that they are perpendicular to the direction of flow through the oven, so that there is equal heating on both pads and none are shadowed during reflow. Naff ASCII picture follows. FLOW _____\ / P = PAD O = BODY OF CAP P = PAD 2) Shadowing? How do I calculate the area that may cause shadowing problems? Given that I know the height & width of the component, what other factors do I need to know? Where on the web can I find some documentation on this? 3) Where (on the web) can I find some good documentation on how "convection" reflow ovens work? Most documents that I can find mention IR. & VP reflow but not convection (which our old QUAD oven is). Many thanks in advance for any helpful replies. Matthew Lamkin Printed Circuitboard Draughtsman Protec Fire Detection PLC. Email matthew.lamkinATprotec-fire-detection.plc.uk [log in to unmask]