The IPC-A-600 guideline describes the acceptance criteria for printed circuit boards that function as a benchmark used by manufacturers and their customers. This set of rules is intended to ensure that flawless shipped PCBs and the electronic devices or equipment that they are part of function reliably.
The IPC-A-600 describes minimum requirements that trained professionals can observe externally or within the PCB to assess manufacturing quality. Whether the quality is sufficient depends on the electronic device in which the PCB is to be used and the requirements it is to fulfil in operation. The technical complexity and the associated manufacturing costs are therefore dependent on the end- use. That’s where IPC classes come in.
Class 1: General electronic products
Includes products of limited useful life, for applications where the main requirement is the function of the complete product. This means consumer products such as games, some computers and their peripheral hardware where superficial imperfections are not important and the main requirement is the functioning of the assembly.
Class 2: Dedicated Service Electronic Products
Includes products that are subject to higher demands in terms of continuous performance and service life and for which uninterrupted operation is desired. In class 2, we are talking about general industrial production, i.e. appliances that are subject to higher demands and require high performance and a long service life. Certain superficial shortcomings can be tolerated.
Class 3: High Performance Products
Includes electronic products for which continuous high functional safety is a condition; in addition, they must function on demand. Functional failure is not permissible. The product must function when it is needed. Products for the commercial and military sector, for which continuous or uninterrupted functional readiness is decisive. Printed circuit boards in this class are used when there are high safety requirements and operation is vital. Failure, such as in life-supporting medical technology, is not tolerable.
The designer makes the classification. The higher the class they specify, the greater or higher the manufacturing costs of the PCB. Higher requirements mean much smaller manufacturing tolerances for the PCB manufacturer.
IPC-A-600 class 2 is considered the industry standard.
It is advisable to design to medium industrial tolerances for PCB manufacture. If you use these tolerances, you can have your PCB manufactured by any manufacturer in the world without expecting significant increases in costs.
Eurocircuits uses the specifications and tolerances as the basis for the most cost-effective pooling service. Here, several PCBs from different orders are manufactured in one use.