What is PCB Milling
Printed circuit board (PCB) milling is when portions of copper are removed from the surface of a printed circuit board material. It is done to replicate pads, signal traces, and structures from a digital circuit board plan (a layout file). Similar to its chemical counterpart, PCB milling is a subtractive process, meaning the material is removed to create the electrical isolation and ground planes needed.
PCB milling is a non-chemical process, which is the largest difference between itself and the common chemical etching process. However, that doesn’t mean that it isn’t just as capable of producing high-quality results. The circuit boards produced from PCB milling are just as well-done, with the added benefit of no exposure to harmful chemicals.
During the PCB milling process, the quality of the printed circuit board comes from the system’s milling accuracy and control and the condition of the milling bits. If kept up to scratch, PCB milling is an efficient way to remove all the copper you need from the circuit board.
PCB Milling Advantages
One of the biggest advantages of PCB milling is that there is no exposure to hazardous chemicals. The process is much safer than chemical etching processing is. Whether the PCB machine is being used for PCB prototyping or specialized PCB designs, there is no need to fabricate the circuit board with chemicals.
It takes time to create a prototype when you’re outsourcing a circuit board. If you want to save some time, you can make a PCB in-house. Also, you’ve got to consider the disadvantages of the wet process for in-house production. There will be too many problems when disposing of the chemicals during the wet process, and high-resolution boards will be difficult to achieve.
To counter this, CNC (computer numerical control) machine prototyping provides much better options! It can provide a quick turnaround for the PCB fabrication process without worrying about wet processing. A CNC machine that is already used for drilling can do both parts (milling and cutting), which saves time and is much more efficient. You can’t go wrong with the drilling, milling, and cutting capabilities of a CNC machine.
If you look at circuit boards that were simple for milling, you’ll find that they end up being quite challenging to process afterward in a laboratory environment through wet etching or manual drilling (i.e., chemical etching processes). A top-of-the-line system is needed to achieve this, which costs a significant amount more than a CNC milling machine would (and again, CNC machines are much more useful).
For the time being, it seems that mass production still favors the chemical etching process. PCB milling is unlikely to replacing etching for a while, though CNC machines are standard practice for smaller production when drilling printer circuit boards.
PCB Milling Processes
· It takes about thirty minutes for the milling process to be completed by a PCB/CNC machine. The bit diameter, size of the circuit board, the number of parts, and alignment of the parts can all change the processing time, but the average is usually thirty minutes.
· Surplus copper is then removed from the circuit board through a process known as PCB fraying. It generates signal lines and routes based on the layout file supplied.
· If further assistance is needed, the printed circuit board manufacturer can provide you with the PCB milling technology.
· Since there is no chemical involvement, the PCB milling process may be carried out in a laboratory environment without any harmful chemicals. Once commenced, it is much quicker for various types of circuit boards.
· You should pay attention to the hardness of the milling bits on the machine. These will directly impact the PCB performance.
· Using the machine for the first time on a big job isn’t recommended. It still takes time to work out all the parts, so you should practice the technique of manufacturing PCB before committing to a larger job.
· You should make sure to do all that you can before using the machine for the circuit board. Ensure that you take the steps required to get the best possible results out of the board. You’ll be able to produce high-quality items accurately this way.
· Raster and Vector are the two main software to use during the PCB milling process.
· Vector data is usually more processed than software-based raster calculations are.
PCB Milling vs. PCB Etching
As has already been mentioned, the main difference between CNC PCB milling and PCB etching is that PCB milling doesn’t use hazardous chemicals to produce the desired result. Though still done in a laboratory environment, a CNC machine is used for the milling process, saving time on things done in the PCB etching process (like wet processing).
PCB etching needs film or direct laser imaging but is generally inexpensive, which is why it’s used more commonly in mass production. It is the most common way to manufacture printed circuit board systems worldwide. However, PCB milling and the use of CNC machines is standard practice for drilling circuit boards. You can’t beat the efficiency and time-saving process.
You don’t need this same film for CNC PCB milling, but you’ll need a machine that costs money to install. As well as the machine, the software is required to operate it. It’s no secret that technology can sometimes fail, so there’s no guarantee that the use of PCB milling won’t come without its share of problems.
There is less difficulty with etching, too, since the FR4 carrier is not etched. Don’t be disheartened if you’re trying to learn to use a PCB milling machine, though. Once you get used to how it works overall, you’ll have a much easier time with it.
Conclusion
The main differences between the two types of PCB manufacturing have been compared. Hopefully, it’s helped you decide if you’re deciding which one works best for you. PCB milling is definitely growing in the industry, but PCB etching is far more common for mass production since it’s far less expensive. Ultimately, it depends on the quality of the printed circuit boards required and the production that goes into it.
