IEC 62435-5:2017

Overview

IEC 62435-5:2017 is an internationally recognized standard developed by the International Electrotechnical Commission (IEC) that specifies guidelines and requirements for the long-term storage (LTS) of electronic semiconductor devices, specifically focusing on die and wafer devices. This standard addresses the preservation of singulated bare die, partial wafers, complete wafers of die, and die with specialized structures such as redistribution layers, solder balls, bumps, or other metallizations.

The document supports storage periods typically exceeding 12 months and is designed to be used alongside IEC 62435-1:2017 for comprehensive storage planning. The goal is to minimize degradation and maintain the quality and functionality of delicate semiconductor components during extended storage.

Key Topics

• Storage Requirements and Conditions: The standard defines environmental controls like temperature, humidity, and atmosphere purity needed for mechanical storage of wafers and bare dice. It emphasizes protection from physical damage and chemical contamination.

• Packaging Guidelines: Recommendations are provided for primary packaging offering mechanical protection and handling safety, including vacuum packing, positive pressure systems, and use of materials with sacrificial or biodegradable properties.

• Failure and Deterioration Mechanisms: IEC 62435-5 outlines potential long-term storage failure mechanisms such as staining, topside delamination, wire bondability loss, and electrical effects caused by inappropriate environments.

• Handling Recommendations: Safe handling techniques for devices on wafer film frames or embossed tape packaging are described to prevent damage during transport or repositioning.

• Periodic Qualification: The standard advises regular inspection and testing of stored devices to verify integrity and identify early signs of deterioration.

• Environmental Controls: Emphasis is placed on maintaining inert atmospheres with controlled purity levels and avoiding exposure to radiation and chemical contaminants.

• Audit Checklist: An informative annex provides a planning checklist to assist in systematic long-term storage management.

Applications

IEC 62435-5:2017 is essential for industries relying on semiconductor components with long service lives or extended production runs, including but not limited to:

• Aerospace and Aeronautical Industries: Where device lifetime often surpasses the commercial availability of components.

• Energy Sector: For devices used in critical infrastructure requiring decades-long operational reliability.

• Railway and Transportation Systems: Applications demanding consistent and dependable semiconductor performance over long periods.

• Electronics Manufacturing: Supporting lifetime buys and strategic storage of components for future production continuity.

• Research and Development Facilities: Where preservation of semiconductor wafers and dies is crucial for experimental repeatability and future fabrication runs.

By implementing IEC 62435-5, organizations can mitigate risks associated with semiconductor obsolescence and ensure that stored devices retain their integrity, functionality, and assembly compatibility after extended periods.

Related Standards

• IEC 62435-1:2017 - Long-term storage of electronic semiconductor devices-Part 1: General requirements. This foundational document outlines overarching principles governing LTS across various types of devices.

• IEC 60068 Series - Environmental testing standards complementary to storage conditions prescribed by IEC 62435-5.

• JEDEC Standards - Widely referenced for semiconductor manufacturing and packaging practices in the electronics industry.

• ISO/IEC Directives Part 2 - General rules for the structure and drafting of international standards, ensuring consistency and clarity in IEC publications.

By aligning storage practices with IEC 62435-5:2017, stakeholders benefit from standardized guidance that enhances the reliability and lifespan of sensitive electronic semiconductor devices during long-term storage. This enables strategic management of component obsolescence and supports sustained production and field service requirements in critical technology sectors.