Solving semiconductor end-of-life for electronics manufacturing

By Anselmn Lim, Regional Manager, South Asia, Rochester Electronics

semiconductorsIndia’s burgeoning electronics industry

India’s National Electronic Policy 2019 can provide an impetus to Make in India (MII) and its efforts to become a global hub for Electronic System Design and Manufacturing (ESDM), apart from making electronics sector more competitive.

The main thrust of the policy is enabling domestic electronic manufacturing to achieve a turnover of US$400 Billion by 2025.The new policy will help build a strong foundation and propel the growth of the ESDM industry in India.

As India’s domestic manufacturing grows to the next level and becomes more export-focused, the skill sets and competence of the India market will rise to the demands. The component supply may be a different situation, as there is a limited supply of components in the market.  This is especially true for components which have reached end-of-life (EOL).  As demands for electronic components surge in the next few years, how can companies in India ensure quality is not comprised when it comes to authentic components?

As the ESDM industry has witnessed upward growth in India and has the potential to become a vehicle of economic growth and development, it is imperative this policy is not sabotaged at the expense of substandard products.

Semiconductor EOL is a perennial problem

SemiconductorEOL is an ever-present problem in every electronics manufacturing industry today, and it’s not going away. The goal has always been to purchase a replacement device that is the exact form, fit, and function as the original.

Lately, companies have been offering a variety to aftermarket “substitute” solutions that claim to be form, fit, and function replacements; however, original equipment manufacturers (OEMs) are finding from experience these parts often fall short of that promise.

Logistically, as well as technically, these substitutes are incomplete, short-lived patches rather than comprehensive, permanent solutions. Throughout the semiconductor industry, in this consumer-driven semiconductor economy, the life expectancy of many components – these substitutes included – can be less than three to five years. Obsolescence is always right around the corner.

Usually the most expeditious and economical response to an EOL notice is to make a last-time-buy (LTB) – to stockpile the number of components necessary for the life of the program. At a bare minimum, an LTB of the semiconductor wafer-level product should be made. However, that is not always possible. Sometimes inventory is not available. Sometimes manufacturers miss the “window of opportunity.” Sometimes manufacturers do not have the financing necessary to make the large, single-order purchase. Or they don’t have the facilities to safely store the inventory if they could obtain it.

As for purchasing the components on an as-needed basis, manufactures are constantly warned to avoid counterfeit and substandard replacement parts by buying only from the original manufacturer or their authorized distributors;hence, availability from authorized channels can be a problem.

Why Aren’t These Substitutions True Form-Fit-Function Replacements?

Many substitute options are created using state-of-the-art silicon foundry technology. While this sounds like a good thing, it can introduce some negative aspects. This new technology may be suitable to replace the functionality of the original device, but it is almost certainly does not replicate all characteristics of the original. This is because semiconductor manufacturers are always trying to get more functional elements onto their silicon, and, to do so, they are continually shrinking the geometry of the elements that go into the silicon. This can bring improved performance to systems and lower costs, but these benefits come with disadvantages that are likely to be significant in high-reliability and safety-critical applications.

What Are the Differences Between the Substitutes and the Originals?

The major difference is the smaller functional cell size used in the new technology.

This leads to:

  • Higher device switching speeds (more susceptibility to noise)
  • Different capacitance (board-level loading changes)
  • Different radiation tolerance
  • Different EMC performance

These parameters are usually not recognized by the manufacturers who make the substitutes because they are not usually fully specified and tested for during device production.

What Problems do These Differences Cause?

Higher switching speeds and different capacitances can cause devices to see spikes and signals or to produce a rare condition in an application that the original parts did not. Any of these conditions could lead to equipment malfunction.

Semiconductors based on smaller cell size are usually less radiation tolerant than semiconductors produced using older technologies. This can lead to latch-up or loss of data. If such a component were used in an avionics system operating at high altitude, for example, aircraft safety would be compromised.

Semiconductors based on smaller cell size are also usually less robust electrically. This can make them more prone to interference from radio and TV transmitter signals and more vulnerable to damage from electrostatic discharges. The latest consumer-driven semiconductor technologies are not designed for 10-year life at the full industrial/military performance limits when it comes to metal migration. These technologies compromise on environmental temperature limits and voltage ranges to achieve similar lifetime guarantees as older technologies.

Sandia Laboratories has released a study that indicates semiconductors based on smaller cell size are likely to wear out much sooner than the originals.

Even though the replacement chips (die) themselves are smaller, the same size package must be used to retain the application fit of the original component. This requires longer bond wires or package leads to the die. In some cases, the die using latest technologies simply gets too small to fit in the same package without creating unreliable packaging and/or a complete package retooling with more aggressive bond finger spacing.

The importance of a certified, guaranteed source

“Substitute” solutions introduce a myriad of failures – sometimes hidden inconsistencies, sometimes obvious, and sometimes difficult to diagnose. These failures are especially unacceptable in high-reliability and safety-critical applications.

What should manufacturers in India be aware of? First, look for continuing suppliers who have been authorized by original semiconductor manufacturers. As they use the original silicon technology, the newly manufactured devices are exact form, fit, and function devices, which guarantees these components work just as the originals.  Manufacturers and design houses that deal in “substitutes” cannot make that guarantee.

Check with the continuing supplier on their inventory of silicon wafers.  When original component manufacturer (OCM) die is no longer available, it is imperative these suppliers have a sufficiently robust inventory of silicon wafers to continue the production.
As India embarks on a new phase of growth towards 2025, companies that will succeed will not only focus on customer engagement, leveraging an agile supply chain but ensuring the highest quality in the manufactured products with zero-failures. This can only be achieved with certified and guaranteed components.

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