The drill bit of the printed board has a straight handle twist drill bit, CNC Drilling Machine a handle twist drill bit and an undercut drill bit. Straight handle twist drills are mostly used for single-head drilling machines, drilling simple printed boards or single panels, CNC Drilling Machine and now in the large circuit board production plant has been rarely seen, the drilling depth of up to 10 times the diameter of the drill bit. In the case of substrate stack is not high, the use of drilling sleeve to avoid drilling bias. At present, CNC Drilling Machine most of the manufacturers use CNC drilling machine, CNC drilling machine uses a carbide cutting handle, which is characterized by automatic replacement of the drill bit. High positioning accuracy, no need to use the drill sleeve. Large spiral angle, chip removal speed, suitable for high-speed cutting. In the full range of the chip flute, CNC Drilling Machine the drill bit diameter is an inverted cone, drilling and hole wall friction is small, higher drilling quality. Common drill handle diameter of 3.00mm and 3.175mm.
PCB drill bits are generally made of hard alloy, CNC Drilling Machine because the epoxy glass cloth complex copper plate on the tool wear particularly fast. The so-called hard alloy is based on tungsten carbide powder as a matrix, cobalt powder as a binder by pressing, sintering made. Usually containing 94% of tungsten carbide, cobalt 6%. Because of its high hardness, very wear-resistant, have a certain strength, CNC Drilling Machine suitable for high-speed cutting. But the toughness is poor, very brittle, in order to improve the performance of cemented carbide, and some used in the carbonization of the matrix vapor deposition of a layer of 5 to 7 microns of special hard titanium carbide (TIC) or titanium nitride (TIN), Has a higher hardness. Some use of ion implantation technology, CNC Drilling Machine titanium, nitrogen, and carbon into the substrate of a certain depth, not only to improve the hardness and strength and re-grinding when the drill when these injections can also move. There are physical methods in the top of the drill to generate a layer of diamond film, greatly improving the hardness and wear resistance of the drill. CNC Drilling Machine The hardness and strength of the cemented carbide are not only related to the ratio of tungsten carbide to cobalt, but also to the particles of the powder. Ultra-fine particles of carbide drill, the average size of its tungsten carbide grain size below 1 micron. This bit, not only high hardness and compression and bending strength are improved. CNC Drilling Machine In order to save costs Now many of the drill bit using the welding handle structure, the original drill as a whole are cemented carbide, and now the rear of the drill handle with a stainless steel, the cost greatly reduced but due to the use of different materials, CNC Drilling Machine the dynamic concentricity less than the overall hard Alloy drill bits, especially in small diameter.