In the PCB industry, it is common to see the terms “through via”, “blind via” and “buried via”. PCB Drilling refers to the board surface drilling between layers and layers of the line connection through the hole.
1. Through-hole (via): only the role of electrical conduction does not have to plug the device welding, the surface can be done to open the window (pad exposed), cover the oil or plug oil.
2. Plug-in holes (Pad holes): need to insert the device welding pin holes, the pad surface must be exposed.
3. No copper mounting holes (Npth): screw holes or device plastic fixed feet, no electrical properties, to locate the fixed role.
Plated Through Holes (PTH) are conductive through holes that carry signals to establish interconnections between different layers of the board and are used to secure components in place during PCB assembly. Component Mounting Holes Non-Plated Holes [NPTH] are non-conductive.
In terms of process manufacturing, they are categorized as:
1. Through-hole. Refers to through the entire board, can be used to achieve internal interconnections or as a component mounting positioning holes in the process easier to achieve, lower cost. 2.
2. blind via. Located on the top and bottom surfaces of the printed wiring board, with a certain depth, used for the connection of the surface layer of the line and the inner layer of the line below, the depth of the hole usually does not exceed a certain ratio (aperture diameter).
3. buried via. refers to the connection holes located in the inner layer of the printed circuit board, it does not extend to the surface of the board.
PCB drilling technology
Divided into mechanical drilling and laser drilling, skilled use of these two different drilling techniques can be realized on the PCB different holes.
1. Mechanical drilling
Mechanical drills are less accurate, but easy to perform, and can drill a minimum hole diameter of about 6 mils (0.006 inches). When used for softer materials such as FR4, mechanical drills can be used for up to 800 impacts. For denser materials, the life is reduced to 200 counts. PCB manufacturers need to choose the appropriate drilling technique for different materials, otherwise it will result in PCB scrap and increased manufacturing costs.
2. Laser Drilling
Laser drilling is a non-contact process in which the workpiece and the tool do not come into contact with each other. The laser beam is used to remove the board material and create precise holes that can be drilled to a controlled depth, allowing precise drilling of holes down to a minimum diameter of 2 mils (0.002″).
Contact opcba.com to get to know the details of PCB drilling or fabricating your PCBs.