PCB Technical - PCB pad printed wire direction and shape of what matters needing attention

Reflow soldering for SMT requires that the pads of both end Chip components should be independent pads. When the pad is connected with the ground wire of a large area, the cross paving method and 45° paving method should be preferred; The length of the lead from a large area of ground or power line is less than 0.5mm, width is less than 0.4mm; The wire connecting to the rectangular pad should be drawn from the center of the long side of the pad, avoiding an Angle.

Wires between SMD pads and lead-out wires of pads are shown in figure. The diagram shows the connection between pad and printed wire.

PCB Manufacturing pad printed wire direction and shape of what matters needing attention

Direction and shape of printed wire

(1) the printed wire of the PCB in SMT should be very short, therefore, if you can go short, do not go complex, follow the easy not complex, can be short not long. It is of great help to the quality control of PCB.

(2) The direction of the printed wire shall not have sharp bending and acute Angle, and the Angle of the printed wire shall not be less than 90°. This is because it is difficult to corrode the smaller inner corners when making boards. Copper foil can be easily stripped or warped at too sharp outer corners. The form of turning is a gentle transition, that is, the inside and outside Angle of the corner is radian.

(3) when the wire passes between two gaskets but is not connected with them, it should be kept at an equal distance from them; Similarly, the distances between wires should be uniform and equal and maintained.

(4) When wires are connected between PCB pads, when the center distance between pads is less than the outer diameter D of the pads, the width of the wires can be the same as the diameter of the pads; When the center distance between pads is greater than D, the wire width should be reduced. When there are more than three pads on the pad, the distance between the wires should be greater than 2D.

(5) Copper foil shall be reserved for common ground wire as far as possible.

(6) In order to increase the peel strength of the liner, a production line without conductive effect can be provided.