Bạn đang xem: Metallic Aluminium-an overview
Thermics, Packaging and Power Component Technologies
Nicolas Patin, in
Power Electronics Applied to Industrial Systems and Transports, Volume 1
2.3.2 Power modules
Power modules are designed to be fixed to a heat sink, and contain several integrated components. They are better suited for medium- and high-power applications than discrete components, and greatly simplify the wiring of the “power” part of a converter, which is partially or completely prewired (some modules can contain all the power components needed to produce an industrial variable-speed drive, such as the one shown in Figure I.1, with the exception of the passive components, i.e. coils and capacitors).
The module has a metallic (aluminum) base to enable it to be fixed to the heat sink. This is covered with a dielectric (e.g. a ceramic element) and with copper leaf, onto which the dies (diodes, transistors, etc.) are soldered. These chips are then interconnected using fine aluminum wires2 (known as “bonding” wires). This technology is known as Direct Bond Copper (DBC), as the chips are connected to a copper surface in the same way as a classic printed circuit (this technology is also offered by the manufacturers of traditional printed circuits, such as Rogers Corp. – offering the Curamikrange). The front surface of the module carries all the electrical connections (for both power and control purposes) required by the environment. At medium and high powers, connections are established using screw terminals to affix an aluminum or copper bus bar carrying filtering capacitors (see Figure 2.5). In certain cases, some of the connections are made using spring contacts, designed to be attached to printed circuits (see Figure 2.6): this technique is particularly suitable for onboard applications, as the spring contacts withstand vibrations better than traditional soldering.
Read full chapter
Chuyên mục: Kiến thức