PCB News - Choose PCB Gong Knife

Choose PCB Gong Knife

Printed circuit boards{Printed circuit boards}, also known as printed circuit boards, are providers of electrical connections for electronic components.
Printed circuit boards are often represented by "PCB", but cannot be called "PCB boards".
Its development has a history of more than 100 years; its design is mainly layout design; the main advantage of using circuit boards is to greatly reduce wiring and assembly errors, and improve the level of automation and production labor.
According to the number of circuit boards, it can be divided into single-sided boards, double-sided boards, four-layer boards, six-layer boards and other multilayer circuit boards.
Since the printed circuit board is not a general terminal product, the definition of the name is slightly confusing. For example, the motherboard used in personal computers is called the main board, and cannot be directly called the circuit board. Although there are circuit boards in the main board, They are not the same, so when evaluating the industry, the two are related but cannot be said to be the same. Another example: because there are integrated circuit components mounted on the circuit board, the news media call it an IC board, but in fact it is not equivalent to a printed circuit board. We usually say that the printed circuit board refers to the bare board-that is, the circuit board without upper components.

PCB gong knives play a very important role in the production process of circuit boards. It affects the accuracy and consistency of the drilling holes formed by cutting. In addition to choosing large-brand PCB gong knives, it is also necessary to consider economic conditions and choose production conditions. The most suitable gong knife.

1. Consider holes.
1) CNC machine tool hole processing generally does not have drilling dies. Due to the rigidity and poor cutting conditions of PCB gongs, the diameter D of PCB gongs should meet the condition of L/D≤5 (L is the drilling depth).
2) Use a center drill for positioning before drilling to ensure the positioning accuracy of hole processing.
3) Floating reamer can be used for fine reaming, and the hole should be chamfered before reaming.
4) When boring holes, try to use a symmetrical multi-blade boring head for cutting to balance the radial force and reduce boring vibration.
5) Try to choose a thicker and shorter shank to reduce cutting vibration.

2. Consider milling
1) Milling cutters with indexable carbide inserts that are not re-grinded are mainly used for milling planes. The diameter of the PCB milling cutter should be smaller for rough milling, and the diameter of the PCB milling cutter should be larger for fine milling. When the machining allowance is large And when the margin is not uniform, the tool diameter should be smaller, otherwise it will affect the processing quality of the workpiece due to the deep cutting of the tool.
2) When processing three-dimensional curved surfaces or workpieces with variable bevel contour contours, ball end milling cutters, ring milling cutters, drum milling cutters, tapered milling cutters, and disk milling cutters are often used.
3) High-speed steel vertical PCB milling cutters are mostly used for processing bosses and grooves. If the machining allowance is small and the surface roughness is required to be high, you can choose an end mill with a cubic boron nitride insert or a ceramic insert.
4) For rough machining of the surface or hole of the blank, a corn milling cutter inlaid with cemented carbide can be used for powerful cutting.
5) For grooves that require high machining accuracy, an end mill with a smaller diameter than the groove width can be selected. The middle part of the groove is milled first, and then both sides of the groove are milled by the tool radius compensation function.

Circuit board manufacturers often do not pay enough attention to the choice of PCB gongs and knives, which may invisibly have a negative impact on quality and cost.