A Dumping Ground For Non-compliant Products
The European commission has issued a revision to the electromagnetic compatibility (EMC) directive - which aims to prevent radio interference from electronic products. The commission claims the revision simplifies regulatory procedures, reduces manufacturers costs and increases product information and documentation available to inspectors.
Günter Verheugen, the European Commissions vice-president in charge of enterprise and industry, said: “The new directive underlines that reducing the administrative burden for industry is a top priority for the commission”. However, one of the changes in the directive could backfire. Under the revised edition, manufacturers can now themselves certify whether a product complies with the EMC directive rather than having this decided by a competent body.
By making manufacturers solely responsible for establishing conformity and CE marking (even if harmonised standards are not available) it must be assumed that manufacturers have the technical knowledge required to assess whether the essential requirements of the EMC directive have been met. If not, the logical conclusion is that the number of non-compliant products will increase. Manufacturers and users of semiconductors are not immune to the potential confusion this could cause. Although individual devices fall outside the scope of the EMC directive, once integrated into an assembled electronic product, semiconductors can significantly contribute to emissions. In many cases, they are the prime source, with the PCB tracks and wiring acting as their aerials. With the speed of digital circuits increasing, so do the potential problems.
Electronics design engineers clearly need to consider semiconductor emissions when specifying components and designing circuits. Therefore, the efforts of semiconductor designers and manufacturers to reduce emissions should be applauded. Unfortunately, not all electronics design engineers appreciate that although competing semiconductor manufacturers produce devices with similar functionality, their individual design methods can result in significantly different emissions.
Thus, if the purchasing department is handed responsibility for selecting the final supplier, the consequences could be disastrous. In theory, by replacing one manufacturers device with an equivalent from a competitor, the products CE mark could be invalidated.
With the migration to lead-free manufacturing gaining pace, design engineers, purchasers and production engineers within original equipment and contract manufacturers are being forced to re-evaluate their supplier base. One wonders whether EMC issues hold a high priority as they race to exhaust their leaded inventory and replace it with lead-free alternatives.
So although semiconductors are not within the scope of the EMC directive, it is obvious that designers and manufacturers of devices, printed circuit assemblies and systems should be aware of EMC issues.