COTS in space: automotive EEE components

Source: Intelligent Aerospace article

April 3, 2018  By Dan Friedlander, Retired following 44 years in component engineering

Automotive-grade electrical, electronic, and electromechanical (EEE) components are a subset of the commercial off-the-shelf (COTS) EEE components population. The prime intended applications for the above subset are the automotive ones. Not all the automotive EEE components are COTS. The custom automotive components are not COTS. Only standard automotive-grade components which come from the manufacturer commercial data book are COTS. 

With the increasing sophistication of future vehicles, new and more advanced semiconductor technologies will be used and vehicles will become technology centers. The above trend leads to increasing interest of EEE components manufacturers in the business opportunities offered by the fast-growing automotive market.

The space industry, within the use of COTS in space dilemma, is also looking at automotive EEE components. That is OK, pending the subject is fully understood. In other words, it has to be understood what “automotive-grade” really means in terms of quality and reliability. The reference for the discussion is industrial-grade regular, catalog EEE COTS components.

The automotive market
The automotive semiconductor market is not large, compared to the total global market. Nevertheless, it is much larger than the space/military market. The automotive market differs significantly from the space market in that the automotive buyer tends to procure high volumes of a small number of devices, while space buyers tend to procure a low volume of a large number of devices.

When one includes integrated circuits, optoelectronics, sensors, and discrete devices, the automotive electronics market reached around $34 billion U.S. dollars (USD) in 2016, representing less than 10 percent of the total semiconductor market. It is predicted to be one of the fastest growing markets over the next five years.

As per McKinsey&Company data the automotive semiconductors market is growing:
“Between 1995 and 2015, semiconductor sales to automotive OEMs rose from about $7 billion to $30 billion (Exhibit 2). With this increase, automotive semiconductors now represent close to 9 percent of the industry’s total sales. Current projections suggest that sales of automotive semiconductors will continue on their upward trajectory, increasing about 6 percent annually between 2015 and 2020 — higher than the 3 to 4 percent growth predicted for the semiconductor sector as a whole. That would put annual sales for automotive semiconductors in the $39 billion to $42 billion range.”

In order not to be misled, it is worth mentioning the estimated automotive semiconductors market per component type.

Acquisitions of automotive electronics specialists by semiconductor giants highlights the semiconductor manufacturers’ interest in this particular market. This growing interest may negatively impact the space/military minuscule market.

Automotive EEE component standardization

The Automotive Electronics Council (AEC) is the leading automotive industry entity for automotive EEE Components de facto standardization. The Automotive Electronics Council (AEC) was originally established by Chrysler, Ford, and GM for the purpose of establishing common part-qualification and quality-system standards.
AEC issued AEC – Q100, “Failure Mechanism based Stress Test Qualification for Integrated Circuits,” the leading document for automotive ICs.

Herein the AEC-Q100 is discussed as representing the relevant automotive EEE components methodology. To promote automotive EEE components the above document is cited in different ways, confusing the users not familiar with the content. The relevant used terms are: AEC-Q100 qualified, AEC-Q100 certified, and AEC-Q100 compliant.
The AEC-Q100 explicitly states:

Para. 1.3.1: “Successful completion and documentation of the test results from requirements outlined in this document allows the supplier to claim that the part is ‘AEC-Q100 qualified’.”

Para. 1.3.2: “Note that there are no ‘certifications’ for AEC-Q100 qualification and there is no certification board run by AEC to qualify parts.”

Para 1.3.2: “Each supplier performs their qualification to AEC standards, considers customer requirements and submits the data to the customer to verify compliance to Q100.”

A NOTICE in the document states: “No claims to be in Conformance with this document shall be made unless all requirements stated in the document are met.”

We learn that whatever term is used, even the only recognized one (“AEC-Q100 qualified”), all the activities and the final verdict is under the specific automotive EEE Components Manufacturer responsibility. The customer is the only external compliance verifier.

The question is how this works in practice. An automotive user is a high volume, valued customer, that probably has the prerogative to access the manufacturer’s qualification data and approve the compliance to AEC-Q100. However, a space small volume user, intending to use an off-the-shelf automotive EEE Component, does not seem to be able to access the data and have any chance to change something.

The applicable car under hood high temperature is up to +150°C. That is outside the industrial operating temperature (up to +85°C). This fact, combined with the issue of high cost military EEE Components, led to establishing the 4 automotive Operating Temperature Grades (ref. AEC-Q100 para. 1.3.4).

Para. 2.1 of AEC-Q100 states: “The objective of this specification is to establish a standard that defines operating temperature grades for integrated circuits based on a minimum set of qualification requirements.”

Para. 2.1,1 of AEC-Q100 states: “Qualification and some other aspects of this document are a subset of, and contribute to, the achievement of the goal of Zero Defects. Elements needed to implement a zero defects program can be found in AEC-Q004 Zero Defects Guideline.”

“Zero defects” should be referred to as a philosophy, a mentality or a movement. It’s not a program, nor does it have distinct steps to follow or rules to abide by.

“The quality manager must be clear, right from the start, that zero defects is not a motivation program. Its purpose is to communicate to all employees the literal meaning of the words ‘zero defects’ and the thought that everyone should do things right the first time.” (Source: Quality Is Free by Philip B. Crosby, McGraw-Hill Books, 1979.)

There are no step-by-step instructions for achieving zero defects, and there is no magic combination of elements that will result in them. There are, however, some guidelines and techniques to use when you decide you are ready to embrace the zero defects concept. The above-mentioned “AEC-Q004 Zero Defects Guideline” is indeed addressing the issue as guidelines.

The term “zero defects” may have different interpretations, as seen below:

AEC-Q004 in para. 6.4 “Environmental Stress Testing” defines the addressed defects before the component delivery to customer:

Para. 6.4.6 “Defect type addressed (ongoing or spike)”

“For design, defects include unusual temperature dependencies, performance irregularities and marginalities, and functional problems. For process, defects include time/temperature defects, unanticipated infant mortality issues, latent defects, and wearout mechanisms. For packaging, defects include structural integrity, unusual package related anomalies (delamination, popcorn) and sensitivities, and assembly related defects that affect quality and reliability. Gross issues are detectable.”

Take another EEE component manufacturer: Altera (now part of Intel). Presenting Altera’s Automotive Quality Program, it is stated that “Quality in Everything We Do to Ensure the Customer’s Total Experience,” meaning “Deliver defect-free products and services on time.”

The “Zero-defect strategy” is presented: “The core of Altera’s ongoing continuous improvement process is its Zero-defect strategy. Altera and its manufacturing partners work closely together to drive down defects by continually implementing manufacturing process improvements and enhancements. Altera’s current customer return defect rate for automotive products is under 1 dpm (defect per million) and our corporate level zero defect roadmap will take us to even lower defect rates.”

Hopefully, the relevant “zero defect” goal is referenced to the “Deliver defect-free products” and not to the “customer return defect rate.” The latter belongs to a different issue. In the same “zero-defect strategy” it is stated: “The following factors play a key role in the success of our comprehensive Zero-defect program.”  As mentioned above, the “zero defect” is not a program.

To correctly assess the “superiority” of the automotive grade EEE components versus industrial EEE components, following are the main elements in the relevant methodology to be considered and not limited to:

• AEC-Q100 is dealing with qualification requirements only.
• A one-time qualification is required for a new device family. No periodic qualification verification is required.
• The use of generic data to “simplify” the qualification process is strongly encouraged.

Para. 3.1 of AEC-Q100 Qualification of a New Device:

“For each qualification, the supplier must have data available for all these tests, whether it is stress test results on the device to be qualified or acceptable generic data.”

• Requalification of a device is required when the supplier makes a change to the product and/or process that impacts (or could potentially impact) the form, fit, function, quality and/or reliability of the device.
• There is no qualifying activity to certify whether the EEE component manufacturer meets the requirements of AEC-Q100.
• The EEE component manufacturer has the authority to self-approve his products as “AEC-Q100 qualified”.
• Each User is responsible to review the qualification data to verify compliance to AEC-Q100.
• Screening is not required.

Nevertheless, it is interesting to find in para. 4.1, Figure 2: Qualification Test Flow, that the qualification is done on components that passed through an undefined step, named “Defect Screening (e.g., burn in)”! No further reference found.

Automotive grade vs. industrial grade

The above highlighted elements of the AEC-Q100, points to a professional document containing a baseline of minimum requirements for qualification. Successful test results after performing all the specified one-time qualification addresses robustness. However, the reliability is not addressed.

An AEC presentation states in context with disadvantages of the stress test qualification methodology (applicable to AEC-Q100): “cannot measure reliability, only can say the test passed (robustness).”

The AEC-Q100 contains a set of tests well known in the semiconductor domain. Consequently, most of these tests (if not all), at applicable test conditions, are applied also for any standard COTS.

The most outstanding automotive tailored parameter is the extended operating temperature range. One of the main issues addressed in the AEC-Q100 is the tests adaptation to the relevant automotive operating temperature grade.

The narrower industrial operating temperature range -40°C – +85°C is in general enough for a space application (always there are exceptions).

The intimate interaction between the EEE component manufacturer and the automotive user, as mentioned in the AEC-Q100 is wishful thinking for a space user.

There is no argument that the controlled qualification baseline documentation in writing has his own value. Nevertheless, it would be worth to know and better understand the difference between an industrial-grade EEE component and an automotive-grade EEE component in terms of quality and reliability and not in terms of operating temperature range. Not having the prerogative of an automotive user (at least as stated in AEC-Q100) to access component manufacturers’ relevant not published information, it is rather difficult (in diplomatic wording) to find explicit production flows for both grades.

A lot of argumentation is available to claim better quality and reliability for automotive EEE Components. The term “AEC-Q100 qualified” is the strongest, most impressive argument. If a “simple” user tries to assess what is done beyond the above one time qualification requirements, he will have to resort to general routine wording/slogans. If one wants to find out what are those advertised “special measures,” “extended measures,” “best commercial practice,” etc., he will probably end up frustrated (like me).

Just to exemplify the situation, take Texas Instruments (TI), a reputable EEE component manufacturer offering automotive grade. TI also offer Enhanced Plastic (EP) grade, considered by them superior. For example, the scenario for trying to find the applicable flow in order to compare grades goes like this:

Question (from TI Enhanced Plastic Portfolio Q & A): “What is the process and test flow?”

TI answer: “Testing and screening of EP products is performed in accordance with the TI data sheet for that device. Configuration control is performed by Texas Instruments. TI processes EP products per “best commercial practices” to the TI internal baseline flow. Processing and screening is documented in the TI Quality System Manual and is in compliance with ISO9001.”

You will not find any flows in the datasheet or in the QSM 000 Rev. H Texas Instruments Quality System Manual. You will find general standard statements.

Here is another TI answer taken from “TI Enhanced Plastic Portfolio Q & A”.

Question: “Why can’t I just buy TI automotive grade parts and get the same thing?”

TI: “Catalog automotive products are just one form of off-the-shelf devices. To ensure change notification and extended baseline support, automotive OEMs procure to specific customer specifications.”

It is worth to pay attention to what the above means:

• “AEC-Q100 qualified” catalog EEE components COTS meet the qualification requirements, but it may be that the automotive users are not purchasing them as is.
• Many large volume automotive electronic system manufacturers DO NOT buy “catalog” automotive grade EEE components. Instead, they procure via internal SCDs based on “AEC-Q qualified” catalog items.

When comparing datasheet of an automotive component versions vs. the industrial version, the operating temperature range is the main difference. However, the electrical parameters (test conditions, limits) may differ as well.
For a space user, assuming that the operating temperature range is not critical, the automotive version may be better (e.g., specified for extreme temperatures vs. specified for room temperature only) or worse (e.g., relaxed limits, worse test conditions). Anyway, as always, the right specification shall be used.

It is worth mentioning that a car bus voltage is only 12V vs. a much higher bus voltage of a satellite.

In most of the cases both automotive and industrial versions of the same component are offered. It does not make sense for the EEE component manufacturer to design and manufacture two different die versions. In other words, the automotive version is an uprated version of the industrial version or the industrial version is a downrated version of the automotive version. In most cases (if not all), both versions have identical dies manufactured on the same production lines. The built-in reliability, in such a case, is the same for the both versions.

One can argue about the robustness obtained through meeting the onetime AEC-Q100 requirements. However, in case of uprating/downrating the compliance to AEC-Q100 should apply also to the industrial-grade counterpart. Of course, the electrical testing test conditions (some manufacturers are calling it “screening”) of each version should be different due to different applicable temperature extremes.

Cars are used by a very large number of users. Obviously, there is no practical need for all the car users to be knowledgeable in every technical detail of a car. Nevertheless, everybody wants to have a good, reliable car to meet the expectations. It is up to the potential car buyers to be aware of gimmicks designed to attract attention or increase appeal.

For example, not everybody is familiar with the professional meaning of the terms “quality,” “zero defects,” and “reliability”. Nevertheless, the words “good quality,” “reliable” is widely used in advertisements and in daily conversations without a deeper understanding.

The term “AEC-QXXX qualified” is used to identify “special” components, designed and tested to meet the “severe” automotive environment conditions and the mission criticality. Be aware of the real meaning of the terminology used in slogans. The above-mentioned term addresses an one time set of tests to be passed by sampled lots. The value of the qualification should not be exaggerated, mixing the terms quality and reliability.

Bosch at ESSDERC 2006 presented “Design Requirements for Automotive Reliability”:

Requirements on automotive semiconductors
The term “operation time” (up to 15 years) may be misinterpreted in context of the subject reliability/semiconductors issue. Here is why.

Large portions of safety-critical embedded systems, such as automotive electronics, spend the majority of their life in the non-operating state (dormant or storage).

Typical Values for Percentage of Calendar Time for Equipment in the Dormant Condition [Harris, 1980].

The above automotive mission profile is less severe than it may look like in the above Bosch presentation table. The operating/nonoperating ratio has a huge impact on major reliability contributing parameters, like temperature and electrical stress.

It has to be mentioned that only a part of the automotive electronics is safety-critical. For example, infotainment systems (navigation system, vehicle audio, information access, etc.) are not critical. Also it should be mentioned that automotive electronics is only a subsystem in the car system. Even after a major transition from mechanical or hydraulic systems to electronically controlled systems (x-by-wire), the mechanical subsystem plays a major role in establishing a car reliability.

Conclusion

• The term “AEC-QXXX qualified” is not a magic proof of better components. Like any term it has to be fully understood in terms of quality and reliability. “The proof of the pudding is the eating.”
• Automotive-grade EEE components, as well as industrial-grade EEE components are subsets of the COTS population. Selected COTS EEE components (minimum -40° – +85°C), although penalized within the present space policy, are viable candidates for space applications. In general (there are always exceptions), space applications require less stringent environment conditions (exclude radiation) than an automotive application.
• In most cases the dies and the package for both industrial and automotive versions are identical. In general (there are always exceptions) for space applications, the industrial operating temperature range meets the requirements.
• The term “AEC-QXXX qualified” addresses qualification and requalification tests only. Traditional screening is not required.
• The term “screening” in context of automotive components is often used for electrical screening at extreme temperatures. Lot by lot testing requirements flows accessibility depends on the purchasing potential of the customer. The automotive customer is a large volume, valued purchaser.
• Many large volume automotive electronic system manufacturers DO NOT buy “catalog” automotive grade EEE Components. Instead, they procure via internal SCDs based on “AEC-QXXX qualified” catalog items.
• The space customer is a small volume purchaser. The automotive electronic components market size in $ is approx. 10%, much higher the military/space electronic components market (0.3%).
• The automotive and industrial grades difference/value added cannot be fully assessed due to lack of access to the relevant information. If the industrial grade meets the intended space requirements, it is not clear whether it is worth to prefer the automotive grade path, tailored for the automotive industry. Both industrial and automotive grades’ availability security is better than the availability security of space/military grade, due to the relevant market size.
• Any reliability assessment of the automotive mission should take into account the relevant hardware and software in operating and nonoperating modes.
• Unless you are an automotive large volume user, you have to rely heavily on the Components Manufacturers for both automotive and industrial grades.

Author biography
The author, Dan Friedlander, graduated Engineering School/Tel Aviv University with a degree in physics (1965-1969). He has 44 years of experience in Component Engineering at MBT/Israeli Aerospace Industries (1969 to 2013), as Head of Components Engineering. As such, he was responsible for all aspects of EEE components – including policymaking, standardization at corporate level, approval, etc. – for military and space applications. Now retired, Friedlander is an industry consultancy (2013 to present).