Reflow Soldering Process: Guidelines for Component Arrangement

1. Consider the direction of the printed circuit board entering the reflow oven when placing components.
2. To prevent tombstone, displacement, and soldering defects, ensure the long axis of two-terminal chip components is perpendicular to the conveyor belt direction in the reflow oven.
3. The long axis of SMD components should be parallel to the reflow oven’s transmission direction, with the two-terminal chip components perpendicular to the SMD components.
4. Ensure a uniform heat capacity and consider the arrangement direction and order of components in a good component layout design.
5. For large-sized printed circuit boards, align the long side of the board parallel to the reflow oven’s conveyor belt. Follow specific requirements for component orientation and arrangement, and maintain consistent characteristic directions for convenient mounting, welding, and testing.
   Additional Guidelines:

• Maintain a distance of greater than 1.25mm between conductive patterns on the edge of inner and outer layers to prevent short circuits.
• Occupied positions due to structural requirements should not have component or printed wire layouts.
• Avoid through holes in the bottom pad area of SMD/SMC to prevent solder remelting during wave soldering after reflow soldering.
• Ensure that the minimum installation spacing of components meets the manufacturability, testability, and maintainability requirements of SMT chip processing.”