In Altium Designer, via-in-pad design rules include the following:
1. The inner diameter of the via hole needs to be set according to the actual situation. In principle, the inner diameter of the full through hole is required to be 0.2mm (8mil) and above, and the outer diameter is 0.4mm (16mil) and above. In areas with small space, the outer diameter can be controlled to 0.35mm (14mil).
2. It is not recommended to use buried blind holes for designs with BGA pad center distances of 0.65mm and above, otherwise the cost will increase significantly. When buried blind vias are needed, first-order buried blind vias are generally used. The inner diameter of the top layer L2 layer or bottom negative L2 via hole is generally 0.1mm (4mil), and the outer diameter is 0.25mm (10mil).
3. Vias cannot be placed on pads with a resistance and capacitance smaller than 0402. Theoretically, the inductance of the leads placed on the pads is small. However, in actual production, solder paste easily flows into the vias, resulting in uneven solder paste and easily causing the device to stand up. Phenomenon. It is generally recommended that the distance between vias and pads is 4.8mil.
4. Vias smaller than 0.5mm need to be plugged and capped with oil, and holes with an inner diameter of less than 0.4mm need to be plugged.