PCB Drill Bit Buying Guide
The PCB drill bits that we sell are made of high quality micro grain carbide. They are used primarily in CNC machines for drilling printed circuit boards for electronics but their toughness and accuracy lend them to uses in other industries. Our M3Tools carbide drill bits are also used in medical and aerospace manufacturing for drilling small precision holes. Carbide PCB drills are well suited for drilling composite materials such as G10 epoxy laminates, phenolic, plastics as well as various metals. They are also widely used for drilling ceramic castings.
What is PCB?
A printed circuit board (PCB) mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it (More About PCB on Wikipedia).
Why trust us?
We hold stock of standard drills in the ST and UC Series. The ST Series are a universal drill bit witch can be used for many materials. The UC Series bits are and undercut bit which is used for small through holes or via interconnectors, they allow improved inner hole wall quality, whilst maintaining good registration accuracy. This makes them ideal for high density multilayer boards.
The drill bits are perfect for drilling FR-4 circuit board materials. The drill element is fabricated of solid carbide since carbide is the preferred material for drilling glass epoxy circuit board laminates due to its exceptional hardness. These carbide bits are capable of several hundred or even thousands of hits before significant degradation of sharpness. The number of holes that can be drilled is dependent on a number of factors including feed rate, speed, material characteristics, and what the user considers acceptable hole quality. Due to the brittleness of carbide these drill bits are recommended for use with drill presses or precision equipment. Care must be taken not to drop or flex them as breakage may occur.
How about our PCB drill bits
Drill has a large scraps discharge space, little resistance and smoothly during the scraps discharge. The cutting edges strictly avoid partial hole, ensure the quality.
Use high-quality materials and fine grinding process makes a bit more sharp cutting edge, reduce cutting force and broken drill, improve the quality of hole wall. Long life, it can drill 2000-5000 pcs under normal working conditions, also can return grinding 4-5 times.
No wobbles and sharp enough to do the job, nice color coded, have the sizes printed on the shafts, come in a handy storage case. The shafts are all the same size, does not need to use a needle-chuck. It makes these bits easier to use.
The smallest one is so small it is hard to see with a magnifying glass, others are perfect for cleaning out small orifices. These are carbide and so you can shatter them if you don’t know how to respect carbide. Power hand drill is no steady enough to use these types of drills, use a drill press instead. And you need to be careful to not put much pressure on the bits when using them, and extremely careful that the only force you apply is along the bit and not to the side.
CNC drill machine
The drilling machine is a preprogrammed Computer Numerically Controlled (CNC) machine. The drill takes place based on the XY coordinates fed into the CNC system. The spindles rotate at a high RPM and ensure an accurate drill hole in the PCB. When the spindle rotates at a rapid speed, heat is generated due to the friction between the hole wall and the spindle. This melts the resin content on the hole walls and results in a smear of resin. Once the required holes are drilled the exit and entry panels are discarded. This is a small gist of what goes happens on the shop floor.
Unlike the etching and plating process, the drilling process doesn’t have a fixed duration. The drilling time varies on the shop floor depending on the number of holes to be drilled. This is what happens behind the curtains in the PCB manufacturing unit.
Quick DFM drill validation tips for PCB designers
- The aspect ratio must be kept minimum to avoid drill wear
- The more number of different drill sizes that are added, the more drill bits the manufacturer will need to use. Instead, if you reduce different drill sizes, the drill time will be cut down.
- For close holes less than 0.006″ if yes it must be addressed
- If vias size should be dropped to meet minimum Aspect ratio (A/R) requirement looking at drill tolerance
- For Plated drill tolerance for less than +/- 0.002″ and NPT drill tolerance of +/- 0.001
- Fab drawing for arcs showing NPT drill/slot or cutout locations but missing in the drill file
- For via filling requirement w.r.t. assembly guidelines
In recent years, the drilling process has been optimized compared to earlier technologies. With the exponential growth in the PCB industry, the drill precision is reaching close to perfection. I believe now you have a better picture of how the PCB drilling process is done.