What does pcb drilling pad mean？

What does pcb drilling pad mean？

PCB drilling pads commonly used by PCB manufacturers are mostly "phenolic resin laminate" and "electrical board for insulation/molding tools", both of which have the characteristics of high temperature resistance and resistance to deformation, and high flatness. The principle is to use processing paper (insulating paper) to immerse in phenolic resin and press it through a hot press to form a plate-like laminated product. The main products of PCB base plate are divided into upper cover plate and lower PCB base plate. The former includes pure aluminum plate, soft and hard aluminum plate alloy, electric board and LE series; The latter includes melamine veneer phenolic board, phenolic resin board, melamine veneer wood pulp board, wood pulp board, etc. PCB manufacturers will cover a thin plate on the top of the PCB board when drilling holes, which aims to protect the panel and reduce the deviation during drilling; Prevent the substrate from burring; The function of assisting the drill needle to dissipate heat and cleaning the drill needle groove needs to meet the five requirements (sufficient softness, good thickness tolerance, flatness, high temperature resistance, low moisture absorption and not easy to deform) when selecting the PCB cover plate. The PCB pad is like our common mouse pad. Its main function is to prevent the reflection and refraction of the surface of special materials such as glass from affecting the positioning of the mouse sensor, and to provide a plane convenient for the mouse sensor system to calculate the movement vector; The purpose of PCB drilling pad is to restrain the burr, penetrate the PCB board, protect the drilling machine and ensure the quality of the substrate. Its characteristic requirements are good flatness, good dimensional tolerance, easy cutting, hard and flat surface, high temperature of the material does not produce viscosity or release chemical substances to pollute the hole wall or drill needle, and the drilling cuttings must be soft, so as not to scratch the hole wall. When PCB manufacturers drill holes in the board, the cylindrical round holes with smaller diameter and larger depth drilled underground with drilling equipment are called "drilling". The diameter of drilling holes for oil and gas and groundwater is larger. The diameter and depth of the borehole depend on the buried depth of geological minerals and the purpose of the borehole; Each part of the drilling hole is represented by: the starting part of the drilling hole is called the "orifice", and the side part is called the bottom of the hole wall is called the "hole bottom". The diameter of the hole is referred to as "hole diameter", the diameter of the hole opening is referred to as "opening diameter", and the diameter of the hole bottom is referred to as "final hole diameter". The distance from the hole mouth to the hole bottom is called the hole depth.