The use of aluminum pcb entry sheet when drilling printed circuit boards is beneficial to improve the quality of printed boards and increase the rate of finished products. Although there is a certain cost to use this auxiliary material, due to the above reasons, the cost is actually reduced. First of all, when drilling the PCB, paddle boards should be placed under the board. The function is to buffer the force and protect the table of the drilling machine. Then, the top of the wooden board must be covered with an aluminum sheet, which is what everyone calls aluminum drill entry sheet. There are three aspects to the role:
1,Heat dissipation, because the drill bit runs at high speed, friction generates heat.
2, Fix the drill bit, reduce the vibration during operation, and prevent the hole diameter from being too large and the hole position deviation caused by the drill bit deviation.
3, Prevent the drill needle from scratching the surface of the PCB circuit board and reduce burrs.
The pcb entry sheet used for drilling requires a certain surface hardness to prevent burrs on the upper surface of the hole, but it should not be too hard to wear the drill bit. It is required that the backing plate itself does not contain resin, otherwise the hole will be greasy when drilling. Aluminum drill entry sheet is required to have a large thermal conductivity, which can quickly take away the heat generated during drilling and reduce the drilling temperature. It must have a certain rigidity to prevent the plate from vibrating when the drill is lifted, and it must also have a certain degree of elasticity to deform immediately when the drill bit touches the drill bit, so that the drill bit can be accurately aligned with the drilling position to ensure the accuracy of the drilling position. If the surface of the drill entry sheet is hard and slippery, the drill bit may slip away from the original hole position.
At present, the aluminum pcb entry sheet used are mainly 0.3~0.5mm thick. Aluminum sheet 1100 has good thermal conductivity and has a certain heat dissipation effect on the drill bit, which can reduce the drilling temperature. Compared with phenolic boards and epoxy boards, the holes will not be greasy due to the resin contained.