Automotive Power Module Packaging: Current Status and Future Trends

Abstract

Semiconductor power modules are core components of power electronics in electrified vehicles. Packaging technology often has a critical impact on module performance and reliability. This paper presents a comprehensive review of the automotive power module packaging technologies. The first part of this paper discusses the driving factors of packaging technology development. In the second section, the design considerations and a primary design process of module packaging are summarized. Besides, major packaging components, such as semiconductor dies, substrates, and die bonding, are introduced based on the conventional packaging structure. Next, technical details and innovative features of state-of-the-art automotive power modules from major suppliers and original equipment manufacturers are reviewed. Most of these modules have been applied in commercial vehicles. In the fourth part, the system integration concept, printed circuit board embedded packaging, three-dimensional packaging, press pack packaging, and advanced materials are categorized as promising trends for automotive applications. The advantages and drawbacks of these trends are discussed, and it is concluded that a preferable overall performance could be achieved by combining multiple technologies. INDEX TERMS Electric vehicles, power electronics, semiconductor device packaging TABLE I PRIMARY DESIGN CONSIDERATIONS OF MODULE PACKAGING Design considerations Details Size Volume, weight, power density, energy density. Electrical performance Current rating, voltage rating, switching frequency range, power loss, electrical insulation, electromagnetic interference (EMI). Thermal management Temperature distribution, thermal resistance (Rth), heat capacity, coefficient of thermal expansion (CTE). Mechanical strength Thermal stress distribution, material properties (Tensile strength, flexural strength, peel strength, etc.), external shock and vibration. Reliability and fatigue Joints failure, crack propagation, delamination, lifetime under temperature and power cycling. Manufacturability and assembly Manufacture procedure, process temperature and pressure, external connections.

The role of power device technology in the electric vehicle powertrain

“…The predominant semiconductor technology in an electric vehicle powertrain converter is the silicon (Si) Insulated Gate Bipolar Transistor (IGBT). 2,3 Each generation of this device has significant electro-thermal improvements, achieving considerable technological maturity, for use in automotive traction inverters* (Figure 1). As silicon technology will dominate the semiconductor market in the short term, 4 and will probably account for approximately 85% of the market by 2025 (Figure 2A), understanding the development of these devices based on silicon technology and their improvements will provide useful insights into their future developments.…”

“…This module is packaged with conventional technology but it includes a direct-cooling heatsink with straight fins bonded to the substrate. 2 Other examples are the inverters of the Chevrolet Volt and the Tesla Model 3, the designs for which were based on 1-in-1 architectures. Some notable features of the Chevrolet Volt inverter are that wire bonds are replaced by a flip-chip soldering technique to improve the current distribution and the reliability of the die interconnection.…”

“…In addition, ceramic substrates are included with a Coefficient of Thermal Expansion (CTE) equal to the CTE of silicon, so as to mitigate the thermal stress. 2 Instead, the Tesla Model 3 inverter has the notable feature of being the first inverter in a commercial vehicle to include silicon carbide devices. 3,21 Following the Tesla vehicle, other manufacturers have since included WBG technologies in the inverters of their own vehicles, specifically made of SiC materials.…”

“…The predominant semiconductor technology in an electric vehicle powertrain converter is the silicon ( Si ) Insulated Gate Bipolar Transistor (IGBT) 2,3 . Each generation of this device has significant electro‐thermal improvements, achieving considerable technological maturity, for use in automotive traction inverters* (Figure 1).…”

Influence of Alloying Elements on the Mechanical Properties of Anodized Aluminum and on the Adhesion of Copper Metallization

“…At the moment, the most innovative products on the market are IGBT power modules from Mitsubishi, which combine the newest silicon semiconductor chips and a packaging approach with new materials and composites [2][3][4][5]. The comprehensive review of the current status and future trends of power modules is presented in [6]. The realities of the modern market require, on the one hand, an increase in the quality and reliability of power modules, and on the other hand, a reduction in the cost of the final product.…”