It's not just about the 'RoHS Six'; it's the compounds that contain them.
What do you make parts out of? Getting a quick and straight answer to this seemingly simple question continues to be a critical and complicated step in the race to comply with RoHS and WEEE. A lack of standards and understanding among all parties including OEMs, service providers, distributors and component manufacturers, coupled with a blizzard of requests in a multitude of formats, is conspiring to change the landscape of material declaration, just months before the European Union's RoHS laws go into effect.
How is an OEM supposed to accomplish due diligence in this environment? Many pitfalls exist, not the least of which is understanding what to ask for and why. Here, we answer that question.
Major issues in assessing component compliance include:
Material compliance with RoHS.
Thermal compliance with higher reflow and wave solder temperatures where SAC (tin-silver-copper) alloys replace SnPb.
Collecting the right data to enable compliance with the various EU states' implementation of the WEEE directive.
Supporting the OEM customer's additional material restrictions and requirements.
The "virtue" of standardization.
Let's address each of these issues. First, there are six classes of materials defined in RoHS. Not six substances; six classes. Each class has multiple substances, including oxides and other compounds for the four metals. PBBs and PBDEs are classes of brominated flame-retardants, each containing many specific compounds. You are not looking for just the RoHS Six; you are looking for compounds that contain them. Exemptions are available for certain uses of some of these materials, including the use of Pb in glass or ceramic. Dozens of Pb-based compounds are used in electronics, as well as several cadmium- or mercury-based compounds, and a few hexavalent chromium compounds as well. The actual number of materials to look for is closer to 100.
Second, material compliance is not the end. While many manufacturers are successfully reflowing SAC alloys at 240°C or so, this is still higher than the 230°C many electronics are designed to withstand. This really becomes an issue with connectors, LEDs, optocouplers and other devices that use plastics that can melt at the elevated temperatures SAC alloys require.
Third, many OEMs and service providers are so focused on the RoHS directive that they, as well as the component manufacturers and suppliers, forget the material requirements spelled out in WEEE. In particular, Annex II calls out several material classes and substances not defined elsewhere - and often overlooked. Combined with Article 11, paragraph 1, there is a reporting requirement that goes beyond the RoHS Six for WEEE. Several EU member states, such as Austria and the U.K., further define "dangerous substances and preparations" to include those defined in Annex 1 of directive 67/548/EEC (as updated by 2001/59/EC). Service providers that do not collect these materials (which include and go well beyond JIG-101's requirements) on behalf of OEM customers are doing them a serious disservice. When using a service provider to collect data, make sure they know what they are doing and know what you need better than you … not all do.
Furthermore, make sure that any supplier that provides a "Certificate of Compliance" (CofC) is also covering the specific information WEEE and the various EU countries require, such as any brominated flame retardant, not just PBBs and PBDEs, in all plastics including IC mold compounds or connector bodies. Also, make sure the CofC is signed by a corporate executive, preferably with fiduciary responsibility. Finally, be sure you understand why you are getting a CofC rather than direct evidence that your supplier knows what their product is composed of. The answers may surprise and scare you.
Fourth, what if you cannot get material data from your suppliers? What do you do? Lots of companies are screening using products like handheld x-ray fluorescence (XRF) technology and thinking that is enough due diligence. It will not be. Run as fast as you can from those suppliers and find new ones. If they cannot tell you what their product is made of and how those materials are controlled lot-to-lot, then you do not want them as a supplier. Some people have forgotten the past 20 years of supplier management best practices: trust through verification, not screening. We have been through screening hell and successfully pushed the responsibility for quality back on the supply base. Is this any different? Yes, RoHS is a new requirement; but why would we think that it is therefore out of control? The industry is now at the "guarantee," not "test," level of supplier management. Drive that level of expectation with your supply base.
XRF does have its place, but only in very limited circumstances. Those are mainly inventory management for distribution, and contract manufacturing, where the ability to tell quickly whether a part has lead on the termination (rather than precise, accurate knowledge of its ppm level) is important. Outside these applications, handheld XRF lacks accuracy and requires too much sample preparation (and expertise in that preparation) and expertise in operation and interpretation to be a useful due diligence tool for the majority of electronics OEMs or even component suppliers. Using it as a defense strategy could be shot down in a court of law - and fast - if this is not well understood.
Fifth, there are additional requirements from the likes of IBM, HP, Nokia, the big Japanese OEMs that subscribe to the Japanese Green Procurement Survey Standardization Initiative, and the attempt at unifying them all, the Joint Industry Guide: JIG-101. If you collect only JIG-101 data, you risk not collecting data your specific customer needs as well as information for future needs. Ensure that you and your data services provider understand exactly what requirements are supposed to be met.
And finally, can we standardize this mess? Will IPC-1752's definition of an XML standard help? Will the PDF form that implements it help? Answer: probably. But it is no panacea. The GIGO principle is in full effect here: garbage in, garbage out. If the level of understanding at either the requestor or component manufacturer is inaccurate, the data will likely be inadequate.
Plenty of consternation remains about just what is a "homogeneous material," for instance. The EU has failed to come up with a definition that will satisfy everyone. Nevertheless, what the EU is trying to achieve is clear: elimination of these materials from electronics. So whether a mold compound for a PLCC device is actually a truly homogeneous material or not (most of the time it is not), and whether it is possible - even for a really tiny person with a really tiny file - to scrape back each of thousands of layers of ceramic and thousands of layers of conductor to separate the materials in a multilayer ceramic capacitor, is not the point. We view this definition as a theoretical thought experiment: it is not intended to define a practical way to determine what materials comprise a component. It defines a practical way to identify excessive concentrations of banned materials.
Reporting requirements will only become more extensive. At this stage, the best we can do is insist on full disclosure (to the extent feasible that also stays clear of proprietary information) from component manufacturers, go after what we know and apply our best technical guess as to what is intended based on all the definitions and hints issued over the past few years. The best we can do for the future is get in front of this as an industry, and get deeply immersed in discussions and development of this sort of legislation with governments around the world. There are plenty of good reasons to design products in an environmentally sound manner; if the industry involves itself in the process, it will also be done more easily, sensibly, profitably and to greater effect than if legislators and NGOs do it alone.