Reliability Impact Study of Printed Wiring Board Manufacturing Quality in Support of the SDV Era

Natsuki Kumagai･Tai Horikawa･Norimitsu Sakai (Nissan Motor)

With the evolution of electric vehicles and the shift towards Software-Defined Vehicles (SDVs), the sophistication of electronic devices supporting driving functions is advancing. While the circuits of printed wiring boards (PWBs) are becoming more complex and high reliability is required for 24-hour operation, the relationship between PWB manufacturing standards and reliability remains unclear. This study quantitatively verified the relationship between PWB manufacturing quality parameters and reliability.

Redefining Moisture Resistance Lifetime Design and Moisture Resistance Testing for Printed Circuit Boards in the Era of SDV

Tai Horikawa･Natsuki Kumagai･Shunsuke Narita (Nissan Motor)･Masatoshi Ando･Kazuya Okada･Masayuki Shimura･Takeshi Yoda･Takenori Kakutani (Taiyo Ink Mfg)

The high temperature and humidity bias test is a standard evaluation for electronic devices; however, its definitions as a durability or quality assurance test are ambiguous, and the methods for determining test specifications remain unclear. This study redefines the positioning of the test and establishes a lifetime design methodology for PCBs. Additionally, it derives a general model of material degradation from test results and prior research, demonstrating the continuous relationship between the Arrhenius model and physical laws.

Consideration of circuit models for in-vehicle printed circuit boards

Yukihiro Serizawa (Sohwa & Sophia Technologies Inc.)

Model-based development using CAE and simulation is progressing as a technology for predicting EMI test results. Printed circuit boards in many automotive electronics units have complex structures and become increasingly dense, and they change depending on external connections and exterior metal structures, making it difficult to create circuit models and electromagnetic field analysis models. This report introduces the outlook for practical use based on modeling of basic structures and examples of prediction.

Proposal for the Mechanism of Whisker Formation and Countermeasures from Sn Plating in High-Speed Communication Connectors

Jun Muto･Hisao Nishimori･Junya Maeda･Miiyu Orinaka･Yasufumi Shibata･Takashi Yamada (Toyota Motor)

In recent years, high-speed data transmission in automotive electronic components has advanced, leading to the use of connectors with various shield housings. This paper reports on the observed cases of whisker formation from Sn plating applied to the shield housings and investigates the mechanisms behind their growth. Additionally, it proposes potential countermeasures based on the test results.

Analysis of solder peeling phenomenon in high-density electronic components and proposal of design guidelines

Yasufumi Shibata･Hisao Nishimori･Akihiro Yamagata (Toyota Motor)

As in-vehicle electronic components have become more sophisticated, ECUs are becoming more densely mounted. However, due to a mismatch between the internal structure of the circuit board and the solder material properties, peeling of the solder joints may occur during the reflow process. This study reports on an analysis of the mechanism behind the peeling of solder joints, and on guidelines for selecting board structures and solder materials for high-density packaging.

Optimization of ECU connector pin signal assignment using quantum-inspired technology

Toshiki Terabe･Daisuke Ibata･Hiroshi Yoshimoto･Yoshinori Suga (Toyota Motor)･Shinji Iwane (Fujitsu)

We have developed a technology that automates the signal assignment to ECU connector pins using a quantum-inspired technology called Factorization Machines with Quantum Annealing (FMQA). The introduction of this technology has significantly streamlined the signal assignment process, which previously required considerable time from skilled personnel, allowing it to be completed in a much shorter time.

Gate Driver CMTI Verification Model Development and Precautions for Power Electronics　MBD Development
-CMTI Verification model in VHDL-AMS-

Noboru Takizawa (consultant)

A gate driver is always used to drive a power device. Gate drivers must adhere to the CMTI specification. This requires that there is no CMTI verification model, and that the verification be performed including SiCMOS, load models, and parasitics on the peripheral circuits and board. This time, we will announce the points to note and the verification model for this verification