Preparing for Impact on Thick-Film Resistors
The upcoming expiration of the RoHS exemption 7(c)-I for lead-glass in thick-film resistors will have significant implications for industrial designs. Many engineers may not yet be aware of the scope of this change, but it is set to affect materials, compliance, and long-term reliability.
Key Technical Considerations
- Lead is currently embedded as lead-glass in resistors, present in the resistive material, glass overcoat, and internal terminations.
- Once the exemption ends, lead content must be reduced below 1000 ppm.
- This will require new materials, requalification processes, and may affect bills of materials, performance, and durability.
Context from Previous Transitions
- Engineers may recall the earlier RoHS-driven shift away from lead in solder and external terminations.
- The difference now is that the internal structure of resistors is subject to regulation, making the transition more complex.
Timeline and Regulatory Outlook
- Current validity: until June 30, 2027.
- Extension requests: can be submitted until the end of 2025.
- EU review period: up to 18 months.
- While the exact compliance date is not yet confirmed, the transition is inevitable.
Recommended Actions for Engineers
- Begin reviewing designs proactively to avoid last-minute disruptions.
- Assess whether current resistors are affected and identify suitable lead-free alternatives.
- Engage with suppliers and technical experts to ensure readiness.
Industry Discussion How is your organization preparing for this regulatory change, and what strategies are being considered to mitigate risks?
