Refining of precious metals

Printed circuit board features

Printed circuit boards are the base on which microelectronic components such as semiconductor chips and capacitors are mounted. They are used to connect electronic components through conductive tracks.

Printed circuit boards typically consist of epoxy resins, fiberglass, copper, nickel, iron, aluminum, and certain amounts of precious metals such as gold, silver, platinum, and palladium. These materials and metals, together with the electronic parts, are attached to the base of the plate with tin and lead solder.


All printed circuit boards basically consist of three main parts:

  1. Impermeable substrate or laminate;
  2. A conductive printed substrate or a laminate within a conductive substrate;
  3. Components attached to the base


Depending on the design, printed circuit boards can be classified as single-sided, double-sided, or multi-layered. The base may be cellulose paper reinforced with phenolic resins. Glass fiber reinforced epoxy resins are commonly used.


Conductive chains on the substrate are printed or engraved from a thin layer of copper foil. Various corrosion-resistant materials such as gold, nickel, silver, tin, tin / lead alloy are used to protect copper during engraving. Various components, depending on their function, are attached to the base using appropriate devices. The process of manufacturing a printed circuit board consists of several main stages. First, using special computer programs, then the board is drawn. The image on the laminated glass textuality plate is transferred by drawing the scheme by hand, using a laser printer, or using a photoresist (for complex, small-volume printed circuit boards). The prepared plate is etched with ferric chloride or a specially designed solution.


Electronic parts are mounted on the prepared board.