Not a straight up answer, but moreover to help you get it: (Circuit Boards)
Aside from the tasks it performs, perhaps the most important function of a circuit board is providing a way to integrate the electronics for a device in a compact space. A PCB allows components to be correctly connected to a power source while being safely insulated. Also, circuit boards are less expensive than other options because they can be designed with digital design tools and manufactured in high volume using factory automation.
Partially straight up, helping you get the answer: (Copper Chloride)
Copper(II) chloride is the chemical compound with the chemical formula CuCl 2. This is a light brown solid, which slowly absorbs moisture to form a blue-green dihydrate.