Chassis as part of the computer accessories, it plays a major role in placing and fixing the computer accessories, play a supporting and protective role. In addition, the computer chassis has an important role in shielding electromagnetic radiation. Although not very important in the DIY configuration, but the use of poor quality chassis is easy to make the motherboard and chassis short circuit, so that the computer system becomes very unstable. Chassis [1]? Generally includes the shell, bracket, various switches on the panel, indicator lights and so on. Shell made of steel and plastic combination, high hardness, mainly to protect the role of the internal components of the chassis. The bracket is mainly used to fix the motherboard, power supply and various drives. There are many types of chassis. The more common ones on the market today are AT, ATX, Micro ATX, and the newest BTX - the full name of the AT chassis should be BaBy AT, and it was mainly used in earlier machines that could only support the installation of AT motherboards. the ATX chassis is by far the most common chassis, and it supports the majority of the types of motherboards that are available nowadays. micro ATX chassis are built on top of AT chassis, in order to further save space on the desktop, and are therefore smaller than ATX chassis. Each type of chassis can only install the type of motherboard it supports, generally can not be mixed, and the power supply is also different. So you must pay attention when shopping. The newly introduced BTX, which is short for Balanced Technology Extended. It is a new specification for desktop computing platforms defined and guided by Intel's BTX architecture, which can support new shapes for next-generation computer system designs, enabling the industry to achieve an optimal balance of thermal management, system size and shape, and noise.The new BTX architecture features: support for Low-profile, i.e., narrow-board design, which will result in a more compact system structure; optimized design for the movement of heat dissipation and airflow on the motherboard's The layout of the motherboard is optimized for heat dissipation and airflow; the motherboard will be easier to install and the mechanical performance will be optimized. Basically, the BTX architecture is divided into three types, namely, standard BTX, Micro BTX and Pico BTX. from the size of the whole series of BTX platform motherboards are not smaller than ATX motherboards, so the development of the BTX is not for smaller desktop computers, but the more flexible circuit wiring and modular component areas, is the focus of the BTX. the BTX case is the most obvious difference compared to the ATX case, is that the motherboard will be more compact, optimized for heat dissipation and airflow movement; motherboard installation will be more optimal mechanical performance will also be designed. The most obvious difference between the BTX and ATX chassis is that the side panels, which used to open only on the left side, have been moved to the right side. The other I/O ports have been moved to the opposite side of the chassis.