Printed circuit boards can’t be taken for granted. No matter if rigid, flexible or ceramic base materials are used they are the carrying structure of the electronic assembly. In order for the electronic product to function the way it is intended the printed circuit board must fulfill certain requirements. The designer sets up the design parameters in the technical drawings, which is part of the documentation set, or procurement documents. In many cases, in these documents, the IPC-A-600 is mentioned as the document of choice as a reference for the inspection.
Delivering the client the printed circuit boards they ordered is very important to guarantee the overall quality of the finished product. The inspector plays an important role in assuring that all circuit boards produced in the manufacturing operations fulfill the specified requirements from the procurement documents. This goes for dimensional as well as electrical properties. In order for the inspector to take the right decisions with regard to acceptance criteria for bare boards or PCB’s these acceptance criteria are gathered in a document called IPC-A-600 standard.
This document deals with various variations that can occur in the printed circuit boards and describes and depicts acceptable and nonconforming situations. It helps the inspectors to make the correct decisions and assures that boards delivered to the customer are within tolerances. Tolerances can be found for typical situations like burrs, nicks, measling, delamination, haloing, conductor width reduction, bow and twist etcetera.
Plated-through holes, as well as unsupported holes, are covered. Specific criteria for via’s both unfilled or filled with resin or copper are integrated now.
Visual inspection criteria for marking are included just like the acceptance criteria for the solder mask.
In one of its 5 chapters, acceptance criteria for the evaluation of cross-sections are discussed, backed up by a vast amount of clear pictures, helping the inspector performing this evaluation and get a better understanding of what to look for. The pictures and illustrations support him to perform his job in the appropriate way. The text tells him what decisions to take.
Typical acceptance criteria for flexible and rigid-flex printed boards are to be found as well as criteria for metal-core boards. Finally, cleanliness testing and solderability testing to the latest methods used in PCB manufacturing are described.
The latest revision of this document is the J-Revision, published in May 2016. It has been updated extensively and now depicts the techniques and materials used in modern printed circuit boards. Important changes have been the addition of criteria for copper filled via’s and the update to the latest versions of test coupons as described in IPC-2221.
PIEK is fully prepared to train and certify both operators and trainers in this latest revision of this document.