Vias are very important to the running of PCB, since they transfer signals between PCB layers. While PCB manufacturing, copper will be added on the boards to make the traces conductive and connect each PCB layer between the holes. In this passage we are going to talk about everything of copper-filled via. Come and check for more information.
What is the process of via filling?
When filling a through hole with copper, the manufacturer must pay attention to creating an even layer of copper in the via without creating too thick an outer layer. Without using the proper techniques, they can create an overabundance of copper that increases PCB weight or adds too much copper to the traces. This results in a failure to meet specifications, defects or increased costs. With via holes becoming smaller than ever, observing these requirements becomes vital to meeting tight design specs.
Classic copper via filling methods involve using pure copper to fill the hole. However, this approach often results in the formation of voids, in which contaminants become trapped in the middle of the copper. This void can release gas when heated during future production steps, creating holes that disrupt the connections between the PCB’s copper layer. Current strategies to counteract this issue include leaving a recess at the top of the blind via filling and creating an “X” patterned connection in through holes.
What are the benefits of copper-filled via?
PCBs featuring copper-filled vias have the following advantages over boards that only have copper-plated vias:
Thermal conductivity: Filling a via with copper increases its thermal conductivity. In applications involving high heat, keeping the heat away from the board will increase its lifespan and prevent defects. Copper’s high thermal conductivity attracts this heat, keeping it away from critical areas of the PCB. Instead of traveling to different parts of the board, the heat instead moves through the copper from one side of the board to the other.
Electrical conductivity: Copper-filled vias also suit applications that require strong currents to travel from one side of the board to the other. The copper’s conductivity allows large currents to cross to deeper layers without overloading the PCB. Because of this capacity, designers often request copper-filled vias for PCBs that will experience high voltage levels.
What are the applications of copper-filled via?
While PCBs that feature copper-filled vias have added capacity, they also cost more to produce than PCBs with plated through holes. Some situations require the added reliability associated with copper-filled vias. However, a PCB can also serve certain applications with a via that has only the copper plating applied alongside the copper traces.
When you decide on your PCB’s vias, you must consider the intensity of the application’s heat and voltage. In low-stress applications, a properly manufactured PCB with plated through holes can function without defects. Meanwhile, PCBs that have copper-filled vias will stand up to the conditions presented by high power, radio frequency, microwave and LED applications. The high-power integrated circuits that run these types of PCBs use currents that a copper-filled via can withstand, but not a plated through hole.