When getting a PCB manufactured, one of the most important steps in the PCBA process is drilling the holes the right way. These holes have an utmost importance and play a very important role in any electronics project. Therefore, if you’re about to get started with PCB and PCBA processing, you must know well about PCB drilling and a deep insight into it.
This article will talk about everything you should know when it comes to PCB drilling, so that you can speak to your PCBA manufacturer properly about your upcoming electronics project.
What is PCB drilling?
PCB drilling implies drilling minute holes in a PCB for various reasons. These reasons can include:
- Holes for the components’ pins, so they’ll be soldered later on.
- Holes to mark the spot where the solder mask needs to be applied.
The PCB holes are also used to harness the PCBA later in the gadget’s housing. That way, the PCBA doesn’t move from its place inside the gadget.
While there can be many more infinite reasons for PCB drilling, the basic idea is to use a certain type of PCB drill to drill different types of holes in the PCB.
What are the types of PCB drill holes?
It’s true that the drill holes in a PCB are classified in different categories, and each of them have their proper definition, meaning, usage, and importance.
- Plated Through
Holes that are drilled in a 2 layer and more than 2 layer PCBs are called plated through holes. These holes have their inner wales covered with some sort of conductor, preferably copper. Therefore, they’re named plated-through holes. The presence of conductor makes the holes conductive, which is why these holes are made to solder electronic components later during PCBA.
- Non-plated Through
Any hole made on a 0 layer or 1 layer PCB is marked as a non-plated through hole. This type of hole is getting depreciated as multi-layer PCB have started advancing. The only reason why manufacturers prefer non-plated through holes sometimes is because they’re cost effective and easy to drill.
PCB Vias are holes, that are used to connect different layers of a PCB. These holes may be drilled from top, bottom, or through all the layers. Vias are only implemented in multi-layer PCBs. Some vias don’t even appear from the top, such as buried via, that’s drilled between the top and bottom layers.
Mechanical drilling Vs. Laser drilling
Mechanical drilling and laser drilling are two type of drilling techniques, that are used to drill holes in PCBs.
1.Mechanical drill helps control how deep you want to drill in a PCB. The mechanical drills can go way deeper than laser drills, which is why mechanical drills have an advantage over a laser drill when it comes to depth control.
2.The bits in the mechanical drills are thick and making holes of very less diameter is impossible. Lasers are very thin and have very shrinking diameter than a mechanical drill. As a result, making small holes such as vias is possible only through lasers and not through mechanical drills.
3.A mechanical drill may not be able to drill on all types of materials, which a laser drill has broad list of materials on which it can drill.
4.Adjusting a laser drill in comparison to a mechanical drill would be tough because laser adjustments have always been very critical. Even a minor mistake, and the hole size can vary. Consistency is very easy in mechanical drill, since you just have to install a bit of the required size and you’ll automatically achieve consistency in hole sizes.
What are types of drilling machines?
- Automated drill machines
Automated drills are controlled through a computer, and a robotic arm drills the holes. Most manufacturers making PCBs nowadays have started using automated drill machines because of accuracy, speed, and consistency.
- Laser drill machines
Laser drill machines use lasers to make holes in a PCB. These machines have a box sort of structure and a laser is embedded on the top. The PCB enters the box, and the laser drill is attached to a computer, that instructs the correct points to drill holes.
How to choose the right drill bit?
Choosing the right drill bit can be challenging when you’re using a mechanical drill. Here’s how to choose the right drill bit.
1.Consider the material that you’re going to drill. One drill ain’t designed for all types of materials.
2.Consider the size of the hole you need. That will help you select the most feasible drill bit size. Each drill bit has its size engraved on it.
3.Consider how deep you have to go in the PCB. Short drills may not be ideal for drilling deep holes.
Common PCB drilling issues and solutions
- Hole Shape Issue
If the hole shape isn’t a perfect circle, or the inner walls are not smooth, then the drill bit is the issue. Try replacing the drill bit with the same size and retry.
- Larger Hole Size Than Mentioned
The drill bit isn’t sharp, which is why the bit is cutting thicker holes in the PCB. Sharpen the bit or replace it.
- Drill Bit Breaking Down Easily
The shaft on which the bit is installed is the issue. The shaft is going out of balance and you need to replace your shaft or get it inspected.
How to minimize the cost in PCB drilling?
The cost of drilling in PCB can be minimized in a number of ways:
1.Optimize the holes count design by eliminating unnecessary holes’ requirement.
2.Consider going for vias rather than through holes.
3.If possible, opt for non-plated through holes over plated through holes to reduce the cost of copper conduction.
By the end of this article, you went through types of holes, types of drill machines, some common problems that the manufacturers face during drilling and some cool tips to control your drilling costs. The next thing to do is to choose a PCB drilling company, such as IBE Electronics, who can take care of your PCB drilling needs. If required, IBE Electronics will support you like answering your queries and helping you to make your electronics project successful.
PCB drilling provides a way to create holes, slots and cavities on the print circuit boards.
- Vibration drilling
- Laser drilling
- Mechanical drilling
- Automated drilling
1.Consider the material that you’re going to drill.
2.Consider the size of the hole you need.
3.Consider how deep you have to go in the PCB.