![]() ![]() Via filling is a PCB fabrication method where the via hole is filled using a conductive or non-conductive epoxy material or copper plating to effectively close the via hole. What is the Difference Between Via Filling and Via Tenting? Tenting should be done on both sides of the PCB, as doing just one side will leave the other side vulnerable to oxidation and corrosion.įor via-in-pad technology, non-conductive via fill is the suitable recourse. When left exposed, the elements can decrease the integrity of the components and lead to corrosion. Therefore, via tenting creates a barrier that can help prevent any damage to the PCB layers from external elements. The solder mask protects the copper traces and the via from oxidizing and corroding. Via tenting also limits the chances of paste migration from SMT pads, which comes about when vias are drilled on standard BGA “dog-bone” patterns or when the vias are on the edges of SMT pads. This lessens the probability of physical damage from corrosion and shorts which happens during solder bridging in PCB assembly. ![]() ![]() The primary goal of via tenting is to leave fewer exposed conductive pads on the surface of the printed circuit board. This method bears many advantages, which are discussed in the following paragraphs: Via tenting is an efficient and cost-effective method of providing protection to PCB vias and the copper around them. When the via gets up to 15mil in diameter, it becomes too large for the tenting method. Smaller vias are typically easier to fill or tent. Tenting has both positive and negative impacts on PCBs, but to answer the question of whether or not you tent the vias on a PCB, the design and manufacturing requirements of the board, as well as the size of the via, hold the answer. Tenting a via usually involves using a solder mask to enclose the annular ring of the via. This filling does not have a significant negative impact on the conductivity of the vias, as there is usually no impedance of electrical signals through the copper plating. Tenting is usually more effective on vias with small holes (12 mils or less in diameter), so it is more effective for larger vias to be filled and closed. However, manufacturers who worry about the tenting coming loose and exposing the annular ring, may decide to use a more expensive resin filling. The most cost-effective form of via tenting is LPI (liquid photo-imageable) solder mask tenting. Via tenting is more often used than mask plugging or epoxy filling because of its cost advantage. Tenting vias of a printed circuit board is a common procedure used to protect printed circuit boards by reducing the number of exposed conductive pads on the PCB. Tenting a via is a process of creating a tent-like covering over the via. Recommended Reading: What is a Via?: A Comprehensive Guide. Tenting is not the only method available, but it is the most common one in PCB manufacturing. Covering vias with different materials allows them to conduct electrical signals while dissipating any produced heat. Many PCB fabricators prefer the tenting method of via coverage. But when the hole is partly closed, the method applied is called tenting. When the hole is completely closed, it is called a filled via or masked via, depending on the covering method. PCB designers and manufacturers may prefer these holes either exposed or covered. Vias are usually copper-plated due to the conductivity of the material. This makes them crucial for PCB manufacturing, especially for multilayer PCB assembly. Vias are plated through-holes on printed circuit boards that allow the transmission of electrical signals from one layer or side of the board to another. ![]()
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