Tips Clearance Tips B.E.C. Manufacturing

Clearance Rules

Ensure your files are in the correct format. B.E.C. accepts Protel 99SE, DXP, Altium Designer 6 and Gerber RS274-X files.

Consolidate your drill sizes.

Holes between 0.3mm to 3.5mm increase in 0.05mm increments. Over 3.5mm drills increase in 0.5mm increments.

Holes larger than 6mm will be routed out. If the hole is required to be plated, an additional charge will be applied. Keep the number of tools needed to a minimum. This will reduce process time and cost.

A limit of 15 tools is included in the standard cost. More than 15 tools will attract an additional charge. We will automatically enlarge holes by 0.1mm on 1Oz plated through boards to compensate for plating thickness. For higher plating thickness we will increase holes by a larger amount to compensate for the copper plated inside the hole. Hole to pad ratio for vias needs to be greater than 5:3. In situations where space is limited, vias can have a min. 6 thou annular ring (0.010" upgrade on your hole diameter).

A 1.0mm hole requires a 1.65mm pad or (in imperial) a 20 thou upgrade, on your hole size. You can reduce the upgrade to 10 thou (0.25mm) if you also accept the risk of not achieving a minimum annular ring as specified by IPC or break-out. Unplated holes used for breakout tabs must not be over pads.

For finished copper weight > 1oz, the track widths will be increased automatically to compensate for etching. Therefore clearance sizes must be increased to allow for the reduction in clearance once the track is enlarged.


The size of the Overlay / Legend Text is to be a minimum 6 thou.

Should the text be a smaller size, then B.E.C. cannot guarantee that all of the text will be visible on the finished product.