Understanding Manufacturing Tolerances on a PCB

Definition of Tolerances for Manufacturing

Manufacturing tolerances are the amount of variation that is allowed in a measurement or other characteristic of an object.

Ref: Collins English Dictionary

Introduction

We all know that tolerances exist in manufacturing and that they have an effect on everything that is manufactured.

Whether, it is a simple a screw, a mobile phone or a spacecraft they are all affected by tolerances and PCB’s are no different.

Even our domestic electricity has a tolerance, for example in Europe it is approximately  +/- 6%.

When you design a new product, you do so with a specific set of dimensions in mind, these are known as the nominal dimensions.

However, these must have a tolerance, no matter how small (or large) they must exist to allow for cost effective manufacture.

We should know that the smaller (tighter) the tolerance the higher the cost of manufacture will be.

For the industrial production of PCB’s there are international standards and these also these tolerances.

All the PCB’s that we produce are done so in accordance with the IPC-A-600 standard.

To helps you to understand where these manufacturing tolerances originate from we have created a series of informative guides.

For more information please select from the titles in the menu on the left.