Part of the PCB fabrication method is drilling holes on the board for the pins of the components to be mounted on. This, of course, involves using a special drill to create holes of varying sizes in the board, depending on its specifications.
In the earlier times, this method was done with a machine being operated by one person and that person manually maneuvers the PCB and drills a hole in it, one at a time. Back then it was not such a tedious task but nowadays, different kinds of PCB can have up to about a thousand holes in them, often even more than that. Drilling these many holes using that old method may just be too much for that one person, especially if the PCB needs to be produced in large amounts.
Fortunately, this PCB fabrication method has become easier with better machines. There are different machines now that can drill holes at a faster rate and with extreme precision. Instead of having a person manually operate these machines, a computer takes on that role. When using an automated machine in drilling holes in the PCB, certain configurations are made such as those involving the size of the hole, its type, and its treatment after the drilling process is done.
When configuring the size of the hole, one considers the relation of the hole to the type of PCB it is going to be drilled into. The thickness of the board and the material it is made of is crucial in order for the mechanical capability of the machine not to be exceeded. This factor is called the aspect ratio. Once the aspect ratio is determined, the drilling machine to be used for the PCB can be selected.
There are instances where the hole needed to be drilled is so small that a laser drill is considered for use. Laser drills are now being utilized as an essential PCB fabrication tool when creating what is called a via. This is the connection of two pads in different layers of the PCB through a drilled hole. There are different types of via. One is called a microvia – this type is used to accommodate high input and output density, usually found in portable devices such as cell phones. Another type is a blind via which is simply a whole that is exposed only to one side of the PCB. Lastly is the thermal via which carries heat away from a power device; this via is usually grouped in dozens.
Such a PCB fabrication method involving lasers is only done by manufacturing companies and carried out mostly with PCBs that need a lot of holes drilled into them in a short time. In most cases, one won’t need such technology to drill holes in a PCB. There are still some tools that can be obtained and modified to be used as a PCB drilling tool. One simply needs a small motor, a piece of plastic or any solid piece to be placed on the tip of the motor, a drilling piece and some wires to connect the motor to a power supply.
Take note however, that in drilling holes into the PCB, the drill doesn’t always have to rotate at the fastest possible speed. Depending on the PCB, one may need for the drill to spin slower to avoid damaging or destroying it completely or one may need it to spin faster for the drill to actually make a hole in the PCB. With that said, one must find a motor with an adjustable speed or some other method to make the drill’s speed adjustable.
Producing PCBs isn’t as simple as many believe it to be. After all, lots of factors need to be taken into account – size is just one of them.