Summary of Why Are Circuits on Boards?

00:00:00 - 00:15:00

This video discusses the history of circuit boards and explains that they are still the most common electrical component. It discusses the pros and cons of integration and off-the-shelf parts and explains that modern devices combine a stiff main board with flex PCB cables and modules wherever the engineer can tuck them.

• 00:00:00 PCBs are the most ubiquitous electronic component, and have been almost unchanged since World War II. PCBs are made of an insulating material, which makes them resistant to high voltages and arcs. PCBs became popular after World War II because they enabled the production of more complex devices and products.
• 00:05:00 PCBs are thin cards with copper foil glued to one side that are used to build electronic devices. The board begins as a sheet of copper clad with a stiff backside and is printed with circuit traces using a chemical-proof paint. After etching away the exposed copper, the board is washed and drilled for components. An engineer manually paints the traces onto a screen used for printing, and this is how old-school circuit boards look. An electrical design assistance program, called EDA, generates artwork for modern boards. The board is then dipped into a resist solution and etched to create the circuit layout. Finally, solder is applied to the circuit layout and the components are attached. Flexible circuit boards are made of a thin heatproof plastic that replaces the fiberglass used in traditional boards. The board can bend but the components cannot, and the board takes damage every time it flexes.
• 00:10:00 This video discusses the history of circuit boards and discusses the pros and cons of integration and off-the-shelf parts. It explains that modern devices combine a stiff main board with flex PCB cables and modules wherever the engineer can tuck them. Flex PCBs are designed to flex just a single time, and that's when the device is assembled. However, boards are still necessary because no part can be integrated into a single chip. Boards are also accessible and cheap, and they are becoming less necessary because many components are now integrated into modules.
• 00:15:00 Printed circuit boards are still the most common electrical component, and they have been unchanged for many years. Boards are best shaped as panes of glass, and are the best way to make transparent electronics. There are many practical problems to be overcome before transparencies can be widely used, but the potential benefits are significant.