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Preface |
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Figure 1. SIP (System in Package); Source: Octavo Systems |
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Multichip Module (MCM) Automotive Verification |
Figure 2 shows the position of Multichip Modules within the AEC-Q family of verification specifications. Their specifications are based on AEC-Q104. However, the current AEC-Q104 was established in 2017. Its specifications are gradually becoming insufficient for the needs of rapidly developing multichip modules, causing numerous problems for both planning and verifying projects. This is when it is important to seek the assistance of those like MA-tek, who have extensive experience with automotive-grade materials, to customize the verification process to ensure different types of multichip modules all meet AEC-Q104 requirements.
 Figure 2. AEC-Q Family Verification Specifications |
 Figure 3. AEC-Q104 Verification Process |
Let us begin by exploring the AEC-Q104 verification process shown in Figure 3. It is said that experts see the essence while laymen watch the spectacle. Upon reviewing the process, most people see only that completing AEC-Q104 verification involves executing both the AEC-Q100 and AEC-Q104 Group H test groups then combining the results into a single AEC-Q104 verification report. However, I have found through my years of studying the AEC-Q family of verification specifications that, when it comes to modules with complex architectures in automotive verification, the verification framework is divided between common, generalized verifications and specialized projects tailored to different characteristics. Take the AEC-Q104, for example. The AEC-Q100 is a common, generalized verification standard while the AEC-Q104 Group H are specialized projects. Other verification for other modules, such as the MEMS (AEC-Q103) and the Optoelectronic Multichip Modules we will be discussing below, are also designed according to this framework.
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Automotive Verification for Optoelectronic Multichip Modules (OE-MCM) |
It can be said that optoelectronic multichip modules are the eyes of autonomous vehicles. They play a crucial role in the future of self-driving cars. So, should optoelectronic multichip modules still refer to the AEC-Q104 or AEC-Q102? This is another question I often hear from clients. As the saying goes, the Devil is in the details. Here, we actually want to refer to the AEC-Q102-003 sub-specification. Generally, when the main AEC specification doesn’t directly reference any sub-specifications, those sub-specifications are often overlooked. This has caused considerable confusion about which specifications should be referenced for optoelectronic multichip module verification. So how should we perform automotive verification for optoelectronic multichip modules? Let us dive back into the world of automotive optical module verification.
First, you should know that the AEC-Q102-003 currently in use was formulated in 2022. It defined the product types of various combinations of OE-MCMs, as shown below in Figure 4. This makes it easy to determine whether a sample is an OE-MCM verification product.
 Figure 4. OE-MCM Product Types |
The AEC-Q102-003 verification process differs from that of the AEC-Q104. The steps are shown in Figure 5. First, determine the internal components of the module and the corresponding general, common test items in the AEC-Q specifications. Then compare to see whether there is any overlap in the test items for the different types of components, as shown in Figure 6. Finally, integrate the common automotive verification items for optoelectronic multichip modules (OE-MCMs). This differs from the AEC-Q104, which only performs AEC-Q100 test items. Now that we have an understanding of the overall AEC-Q104 and AEC-Q102-003 verification processes, what are the differences between these two regulations? Let us continue our exploration.
 Figure 5. AEC-Q102-003 Verification Process |
 Figure 6. A Comparison of Test Items for Different Types of Components |
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Differences Between AEC-Q104 and AEC-Q102-003 |
Considering they both relate to automotive specifications, how are AEC-Q104 and AEC-Q102-003 different? This is a question many ask. I have summarized the differences in the table below:
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The above comparison reveals that the two specifications differ in four areas: sample size, normal qualifications verification, module specific verification, and board-level reliability. In practice, verifying board-level reliability for automotive modules often presents a challenge. Many customers have asked us what they should do if they cannot design a daisy chain for their module. How can they determine if a solder joint has failed? In such situations, I have suggested using failure analysis techniques. However, this approach was still difficult to implement because the standards did not provide the relevant guidelines. It wasn’t until the 2022 version of the AEC-Q102-003 specifications that red ink analysis was introduced, thus resolving the longstanding question of what to do about failure analysis when module designs do not allow for a daisy chain to test board-level reliability.
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In Summary |
Due to the wide variety of automotive modules, there are often issues with the applicability of specific test items. If you are still confused about how to verify AEC-Q Multichip Modules, you are welcome to consult MA’tek’s professional automotive certification team. MA-tek can assist you with planning how best to conduct your verifications in accordance to AEC-Q104 and AEC-Q102-003 requirements.
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Consultation hotline |
Contact Window: Mr. Zhang
Phone: +886-3-6116678 ext：4209
Mobile: +886-979-713-023
Email: AECQ@ma-tek.com
