Use of Copper Clad Laminates for Printed Circuits Boards
Copper clad laminates or aluminum copper clad laminates are the main components used in the manufacturing of printed circuit boards (PCB). PCB is the combination of non-conductive substrate and copper layer on the one or both sides of the substrate.
The number of copper layer around the substrate can be different according to the application of PCB ranging from one layer to fifty layers. The substrate provides a suitable surface for the soldering of different components on the board while copper-clad lamination aids in connecting the components on the board.
A printed circuit board is mainly composed of six components
Reinforcing material or Prepreg
Nomenclature and final finish
Reinforcing material or prepreg is composed of fiber glass dipped in resin. The resin used for this purpose is usually polymide, F4 epoxy and Teflon. The resin is heated at a temperature of about 300oF to make the resin melt and soften.
Then fiberglass is dipped into resin and this process is called thermosetting. After the process of thermosetting the resin is cooled again to make it rigid and strong to go for further process of attaching laminates.
These laminates are called copper clad laminates which are composed of prepreg sheets laminated by copper or aluminum clad laminates. The prepreg is laminated by using high pressure and high temperature. This lamination could be one sided or at the both sides of sheet. When the lamination process completes the boards are like plastic sheets with copper or aluminum lamination.
After the lamination with copper foil the board is etched to make the board circuitry. These circuits play the role of electric wiring on the external and internal layers of board. After the etching of circuits, these circuits are laminated again with the prepreg.
The internal circuits got buried with prepreg and for external circuits solder mask is used. Solder mask is epoxy coating at the outer layer to cover the external circuits. If the external circuits left unprotected they will corrode and oxidize with the passage of time that will decrease the shelf life of board.
Nomenclature is process of defining different circuits on the board. You can see them as white letters defining different paths on the board. In the procedure of final finish the holes and leftovers at board are filled with different metallic coatings like gold, tin, nickel, etc.
Aluminum copper clad laminates are trending now a days due to their high quality and good conductivity. DK Enterprises are well known dealers of copper and aluminum clad laminates. You can get more information about copper clad laminates at DKEnterprise.ind.in