System-on-chip

A system-on-chip, or SoC, is a whole computer's worth of circuits on one piece of silicon. In a smart TV it's the brain: it runs the operating system and apps, decodes streaming video, scales and enhances the picture, handles the sound and sends the image to the panel.

Its silicon die holds several blocks side by side: a few processor cores, usually based on Arm designs, a graphics processor, dedicated video decoders for formats like HEVC and AV1, a picture-processing engine, and controllers for memory, HDMI and USB. The die is packaged by flip-chip. Tiny bumps of solder or copper are formed on its pads, and it's flipped face-down onto a package substrate, where the bumps melt and bond. This allows far more connections than wires could, right where they're needed. The gap under the die is filled with resin, and mold compound or a metal lid covers it. Finally, a grid of solder balls is attached underneath, making a ball grid array.

The SoC is soldered to the main board, next to its memory and storage, often with a heat sink on top. TV makers either design their own or buy them from chip companies such as MediaTek.