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www.us-tech.com
May, 2018
Long-Term Component Storage Prevents Obsolescence Issues
By Holger Krumme, Dipl.-Ing., Managing Director — Technical Operations, HTV Halbleiter-Test & Vertriebs GmbH D
uring product development, or even shortly after launch, single components often go ob- solete. Decisions about how to proceed then
have to be made, including the option to redesign the product, or make a last-time buy (LTB) to en- sure the availability of the required parts until the product’s discontinuation or product change notifi- cation (PCN). The issue of discontinued products is escalat-
ing, due to the increasing number of huge semicon- ductor companies merging. Unprofitable or redun- dant product lines are cut off with little notice. Proactive and strategic obsolescence management in a company proves to be very difficult. Even the method of storing the required com-
ponents involves underestimated risks. Only a qualified storage design, tailored to the compo- nents, ensures their functionality and usefulness after being stored for several years. Many companies establish divisions that are responsible for coordinating obsolescence, which
With large semiconductor company merges, redundant product lines are cut off with little notice, making obsolescence management strategies very difficult.
communicate directly with company management. To prevent obsolescence and to solve related issues, this division must be involved with product develop- ment, quality management and the purchasing de- partments. It is essential to specify components ac-
Long-term storage is particularly beneficial for displays.
long-term storage of components in order to elimi- nate risks through poor functionality or process- ability. The commonly held opinion that storage in nitrogen dry packs will halt the aging processes is wrong.
With a nitrogen-exclusive atmosphere, oxida-
tion is reduced, but not eliminated. Even in the standard packing process, the so-called nitrogen dry packs still contain percentages of oxygen. The aging processes, such as diffusion or corrosion
cording to the availability of a second source, in order to deal with sudden discontinuation. However, even with a precise and proactive
obsolescence management strategy, the need for an LTB cannot be avoided completely. What is more important is the appropriate and qualified
caused by outgassing hazardous substances, will not be minimized at all.
Thermal-Absorptive Gas-Barrier To ensure the long-term availability of elec-
tronic components and spare parts, HTV devel- oped its TAB® procedure, a thermal-absorptive gas-barrier system. This enables the storage of components and assemblies for up to 50 years, by reducing physicochemical aging effects. Usually, components are affected by aging after only one or two years in conventional storage. As one of the global market providers of test-
ing, component programming, long-term conserva- tion and storage, as well as analytics and compo- nent processing of electronic components, the HTV group invested its experience of more than 30 years into the development of its TAB program. TAB permits the long-term prevention of cor-
rosion and oxidation processes, based on special ab- sorption systems —humidity, oxygen and hazardous substances, depending on the material. The aging processes inside the component, the diffusion at chip level, as well as material migration at chip level and pin level is significantly minimized with TAB. Even the risk of whisker formation is con-
trolled. Whiskers are tiny tin needles that grow out of the material and can lead to short circuits on PCBs or single devices. The growth of the inter- metallic compound can nearly be stopped, for in- stance between the external tin coating and the base material of the pins, as well as the aging due to diffusion processes at chip level. This way, the quality, processability, func-
Continued on page 30 ESD-SAFE™ LABELS and TAPES
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