Due Diligence Verification: The Results
December 31, 1969 |Estimated reading time: 4 minutes
RoHS compliance requires electronics manufacturers to incorporate measures ensuring all electronic components meet the EU’s directive banning hazardous substances. This article details one EMS provider’s work to implement a verification program using X-ray fluorescence (XRF) analysis to reduce risk exposure and improve compliance documentation.
By Scott Mazur, Benchmark Electronics Inc.
XRF technology is handheld, portable, and non-destructive to electronic components and systems. This methodology replicates the expected mode of RoHS-compliance verification used in the European Union (EU). As previously detailed,1 one EMS firm* took steps to implement a verification program using X-ray fluorescence (XRF) analysis to reduce risks and improve documentation.
Verification Process
The process deployed by the EMS firm is a “trust-but-verify” approach. The firm monitors the supply chain at several critical stages of the manufacturing process. The initial verification of electronic components occurs during incoming receipt. This detection point is the first line of defense to verify that the specific material is RoHS-compliant per supplied material declarations or certificates of compliance. The second phase consists of testing process materials during manufacturing, and monitoring critical lead-free process parameters.
Figure 1. Pareto chart of banned substances detected.
The final detection point during the manufacturing process is the finished product. The goals are to complement incoming receipt, and verify known industry or historical non-compliant components during the final-assembly manufacturing stage. Documentation of XRF results must be maintained to provide proof of testing and a history of compliance. Streamlining record retention will simplify the process, especially if the EU compliance-enforcement authorities detect a request or nonconformance.
Results
Since the RoHS deadline, the due diligence verification process has detected multiple non-compliant components. These components, and resulting RoHS-banned substances, have been confirmed as non-RoHS compliant by the manufacturers and its suppliers. Figure 1 shows a Pareto chart containing detected banned substances. The time frame of the data captured was from July 1, 2006 through October 31, 2006. Approximately two banned substances per week have been detected since RoHS went into effect. The banned substances were not declared as an exemption, and have been confirmed by the supply base as non-RoHS-compliant material. The top driver, lead (Pb), was detected in a variety of IC components, wire/cables, and transformer products. The cadmium findings were associated with wire/cable and gasket products. The hexavalent chromium (Cr6) and polybrominated diphenyl ether (PBDE) were associated with connector and wire/cable products. The base element (chromium and bromine) was discovered; further investigation revealed a presence of the RoHS-banned substance. XRF technology cannot detect the RoHS-banned substance (Cr6 & PBDE), but can discern the base element (chromium and bromine).
Figure 2. Pareto chart of non-compliant occurrences by component type or commodity.
Figure 2 details a Pareto chart of the non-compliant occurrence by component type or commodity. The wire & cable commodity has resulted in the highest non-compliance rate detected during the due diligence verification process. Several banned substances have been detected within the component type, including lead and cadmium within the wire & cable structure. Both conditions are industry known and reported at numerous seminars.
Lead also has been detected on the wire terminations, which results in noncompliance for non-RoHS-5 exempt customers. Resulting investigation revealed that the terminations were being coated or tinned with a lead solder alloy.
The hardware commo-dity exhibited non-exempt lead within the material, or detected at a solder connection. Two of the banned substances - lead and hexavalent chromium - were detected for the connector-component type. The lead on the termination plating was verified as non-exempt, with the hexavalent chromium located on the metal housing. To reiterate, the base element (chromium) was discovered; further investigation revealed the RoHS-banned substance that cannot be discerned by XRF technology.
Conclusion
Given the initial findings, verification testing has been modified to focus on the commodities demonstrating the greatest occurrence of non-conformance and their associated components. The XRF-testing protocol also has been modified, given the banned substances detected and location on the commodity. As an example, the XRF testing of a wire/cable was modified to verify multiple locations including the center body and terminations. Numerous corrective-action requests have been issued to manufacturers. The supplier’s root cause indicated that there was an inadequate testing protocol, insufficient analysis of the supply base, and a misunderstanding of the RoHS directive principles.
One non-compliant component can result in a rejection of the entire product by EU authorities- with potential for significant legal penalties and loss of sales. Instituting a compliance program enables detection of the non-conformances during the manufacturing process, where problems can be corrected. The banned-substances detection and subsequent confirmation by manufacturers and suppliers have resulted in the proactive substitution of RoHS-compliant material into a customer’s products. This illustrates the effectiveness of a due diligence verification program. The deployment of such a program will provide a verification process, while dramatically reducing the compliance risk involved with manufacturing products that ultimately will reside in an EU member state.* Benchmark Electronics, Inc., Hudson. N.H.
References
- Scott Mazur, “Due Diligence Verification - Ensuring RoHS Compliance,” SMT, March 2006, pp. 30-31.
Scott Mazur, RoHS specialist/principal quality engineer, Benchmark Electronics Inc., may be contacted at (603) 879-7000, ext. 8004; e-mail: scott.mazur@bench.com.