The aspect ratio relates to a ratio based on a hole length relative to the same hole diameter on a pcb. This includes through-hole plated holes, blind vias, buried vias, and micro vias. The aspect ratio applies to both mechanically and laser-drilled holes.

Capacitance refers to a fundamental electrical property that describes the PCB’s or its components’ ability to store an electric charge. It is a crucial parameter in PCB design and can have significant implications on the functionality and performance of electronic circuits. Capacitance is measured in units called Farads (F), which represent the amount of charge (in Coulombs) stored per unit of voltage (in Volts). However, in practical PCB applications, the Farad is often too large, so capacitors are usually rated in smaller units like microfarads (μF), nanofarads (nF), or picofarads (pF).

Conductive Anodic Filament (CAF) is a phenomenon that can occur in printed circuit boards (PCBs) where electromigration by means of a copper salt filament takes place between two points (anode to cathode) inside the pcb and is related to the failure of the board due to the formation of conductive traces between different copper features, such as traces and planes, through the insulating material (resin) that separates them.

Edge plating or castellation refers to the copper plating that runs from the top to the bottom surfaces of the circuit board and extends to at least one of the perimeter edges. Essentially, both edge plating and castellation processes take place during through-hole plating, the routing for the castellations where the “half holes” are created will take place during the profiling process.

Nearly all Flex and Rigid-Flex boards are constructed using a polyimide material. This material is naturally hydroscopic, which means that it easily and readily absorbs moisture. It is therefore strongly recommended that flex and flex-rigid boards be baked to reduce the moisture content prior to any assembly process that requires soldering. Risks such as delamination, inner layer separation or cracking of the through hole copper walls may occur if the pcb’s are not baked prior to being exposed to the assembly process.

This PDF from Cirtech Electronics presents a range of PCB stack-up configurations for 4 to 12-layer boards. It provides essential details on layer arrangements, material thicknesses, and impedance considerations, helping designers optimize signal integrity, manufacturability, and performance for their specific applications.

The shelf life of pcb’s are dependent on the storage conditions as well as the surface finish. The laminate material is sensitive to moisture absorption and the surface finish of the pcb’s can be affected by contamination and oxidation.

This PDF provides a comparison of various PCB surface finishes, outlining their advantages, limitations, and typical applications. It serves as a useful reference for engineers and designers selecting the most suitable surface finish for their printed circuit boards (PCBs) based on factors such as cost, solderability, shelf life, and environmental considerations.

Via hole plugging is a PCB manufacturing technique in which the via hole is filled with a solder mask or epoxy. This process partially or completely closes the via hole using conductive or non-conductive filling material. Filling via holes results in more reliable surface mounts, provide better assembly yields and improve the reliability of the PCB by decreasing the probability of trapped air or liquids in the via and thus the PCB Board.