Drills introduce common

Configuration which substantially radial cutting edge portion having at least two main cutting edge portion, and arranged in the circumferential direction of said main cutting edge portion and between the main cutting edge portion, at least two sub cutting blade portion said main cutting edge portion includes a main cutting edge as the cutting blade, the cutting blade inner end of the main center of rotation, the outer end of the cutting edge portion in the outer periphery of the rotation locus.
A cutting edge portion of the Diamond tools  sub cutting blade as the sub cutting blade, the sub cutting blade inner end is located off the center of rotation to the outer side of the site, the outer end is located in the rotating cutting blade portion deviated from the center of rotation locus of the outer edge position.
A drill, with a drill tip disposed on the plurality of cutting blade portion, and provided on the base end side of the cutting blade portion and the base end portion of the shank portion is formed with a shaft-shaped drill main body;
Said cutting blade portion has a flank of the cutting surface and the engagement surface protruding toward the front end edge of the cutting edge formed by said center of rotation of the cutting blade from the drill side arranged substantially radially outer side;
The rotary axis of the direction of movement and the operation of the impact operation of cutting the composite, characterized in that said cutting blade portion has at least two main cutting edge portion, and disposed in the circumferential direction of the main cutting edge portion and the main cutting between the blade, at least two sub cutting blade portion;
The main cutting edge portion having a cutting edge as a main cutting edge, an inner end of said main cutting edge is located in the center of rotation, the outer end of the cutting edge portion in the outer periphery of the rotation locus, the sub cutting blade portion having as its the sub cutting blade cutting edge, the secondary cutting blade inner end is located radially outwardly from the rotation center deviate from the site, the outer end portion in the rotation from the cutting edge to the center of rotation locus of the outer side of the deviated position.
PDC bits
PDC bits [1] for short. Is commonly used in the oil drilling industry as a drilling tool.
PDC continuous improvement of product performance
In the past few years, PDC cutter quality and type have undergone tremendous changes. If the teeth of the 1980s to today's teeth for comparison, the difference is quite large. Because hybrid technology and manufacturing process changes, today's cutting teeth is much better quality and performance, so that the anti-erosion and impact drill capabilities are greatly improved.
Engineers also tungsten carbide substrate and the interface between the diamond has been optimized to improve the toughness of the cutting teeth. Process innovations in the diamond layer is also used to improve the abrasion resistance and thermal stability.
In addition to material and  drum wheels manufacturing process developments outside, PDC products in the tooth tooth design techniques and fabric also achieved a major breakthrough. Now, PDC products have been used previously can not be applied in areas such as stiffer, stronger and changing abrasive formations. This extension to new areas, the diamond (fixed cutter) cone drill bit and the balance between a great impact.
Initially, PDC drill bit can only be used for soft shale formations, the reason is hard mezzanine will damage the drill bit. However, due to the emergence of new technologies and changes in the structure, the current PDC drill bit for drilling hard interlayer has been able to and a long section of the hard rock formations. PDC bits are increasingly being used by people, especially with the continuous improvement of quality PDC teeth, in which case more and more prominent.
Since teeth bit design and improvement, PDC drill bit orientability also will increase, which further weakened the past in motor drilling cone bit advantage. Currently, PDC drill every day in many applications where the drilling supplant cone drill bit market.
Commonly used mechanical drills, twist drills with straight shank (ordinary type), you can drill: 45 # steel, stainless steel, diamond hardness using the weak point of the material. Alloy drill, you can drill Cr12 steel, the use of diamond hardness strong material. Use drill expertise can allow himself to lower profits.
PCB Drill Type
PCB drill drill drill control Type: PCB drilling with a drill with straight shank twist drill, fixed and fixed shank twist drill shank Spade (undercut) drill bit. Straight shank twist drill mostly for single head machines, PCB drilling relatively simple or single panel, now in a large circuit board manufacturing plant has been rarely seen in its drilling depth of up to 10 times the diameter of the drill. Laminated on the substrate is not high, the use of drill bit holder to avoid bias.
At present, most manufacturers use CNC drilling machine, CNC drilling using a carbide shank drill set, which is characterized to achieve automatic replacement drill. High positioning accuracy without the use of drill sets. Large helix angle, chip speed, suitable for high-speed cutting. In the range of the flute length, diameter of the drill is an inverted cone, when drilling with the hole wall friction is small, high quality drilling. Common drill shank diameter of 3.00mm and 3.175mm.
Drill material
PCB drilling with carbide drill bit is generally used as the epoxy glass cloth complex copper plate on the tool wear particularly fast. The so-called carbide drill gold is tungsten carbide powder as matrix, cobalt powder as a binder by pressurized sintering. Generally contain 94% tungsten carbide, 6% cobalt. Because of its high hardness, very wearable, a certain strength, suitable for high-speed cutting. But the toughness is poor, very brittle, in order to improve the performance of cemented carbide, and some use carbide substrate in a chemical vapor deposition on a 5-7 micron layer of special hard titanium carbide (TIC) or titanium nitride (TIN), to has a higher hardness. Some use ion implantation technology, titanium, nitrogen, and carbon injection the matrix certain depth, not only improves the hardness and strength and regrinding the drill can move into when they injected ingredients. There is a physical method to generate the bit at the top of a layer of diamond film, which greatly improves the hardness and wear resistance of the drill. Carbide hardness and strength, not only the ratio of cobalt and tungsten carbide, but also with the powder particles about. Carbide drill ultra fine particles, and its average grain size of tungsten carbide with 1 micron or less. This bit is not only high hardness and compressive strength and flexural strength are diamond bandsaw blades  improved. To save costs Many drill shank welded structure, the original as a whole are carbide drill, drill shank back now made of stainless, but significantly reduced the cost of the material due to different concentricity less than its dynamic rigid whole alloy drill, particularly in the small diameter side.
The use of drill
1, the drill should be packed in special packing boxes, to avoid vibrations collide.
2, when used, from packing boxes should immediately remove the drill bit attached to the spindle collet header or automatic replacement drill tool library. Spent immediately put back packing boxes.
3, use the drill diameter measurement tool microscope and other non-contact measurement equipment, to avoid the cutting edge in contact with the mechanical gauge was bruised.
4, some CNC drilling machine CNC drilling using some positioning ring retaining ring is not used, such as the use of its positioning ring installation depth positioning must be accurate, as it does not use retaining ring fitted to the drill spindle elongation to adjust consistent, multi-spindle drilling machine to pay attention to this point, to make each spindle drilling depth to be consistent. If not possible to make drill drill drill through the surface or not caused by circuit board scrap.
5, using 40 times the usual three-dimensional microscopy drill blade wear.
6, the spindle and to always check the concentricity of the collet and the collet chuck clamping force, will result in poor concentricity of small diameter drill bit off and pore size, etc., the clamping force will cause the actual speed is not good Set speed does not match between the chuck and the drill bit slipping.
7, fixed shank drill head clamping collet drill shank length of 4 to 5 times the diameter to clamp securely.
8, should always check the spindle presser foot. Presser foot contact surface perpendicular to the spindle is horizontal and not shaking, to prevent drilling off the drill and produce partial holes.
9, drilling better than vacuuming, vacuum air temperature can be reduced drill, colleagues away dust reduce friction generates heat.
10, the substrate stack comprises upper and lower plate to drill a hole workbench trough positioning system to locate a prison, lie flat. Use adhesive tape to prevent the drill bit to be on the tape so that a drill swarf adhesion, causing difficulties and chip off the diamond.
11, ordering manufacturers drill, the factory inspection when sampling the compliance of its 4%. And 100% of 10 to 15 times with a microscopic examination of the gaps, scratches and cracks.
12, drill timely re-grinding, increase the use and re-drill grinding times, extending bit life, reduce production costs and expenses. Microscope usually measured length of the two main cutting edges, the wear depth should be less than 0.2mm. Regrinding when rubbed 0.25mm. Plain shank drill can be reground three times, shovel-shaped head (undercut) of the drill can be reground two times. Excessive turning grinding quality and accuracy of its drilling will decline, will cause the finished circuit board scrap. Excessive turning mill backfired.
13, when the wear due to abrasion and diameter reduction of 2% compared to the original, then the bit scrapped.
14 bit parameter settings in general, manufacturers have to provide a drill bit plant production speed and lower speed parameter table, the parameter is a reference only, the actual craft workers through actual use but also draw a line with The actual speed and the speed of the drill parameters are usually the reference parameter actual parameters are different but the difference is not too much.
The concept of drill
Bit is used to drill out the solid material through holes or blind holes, and is able to have a hole reaming tools. Twist drills are commonly used, flat drill, center drill, deep hole drilling and core drill. Reamers and countersinks although not drill holes in solid material, but will also be used to drill them into a class.