How Not to Mill a Printed Circuit BoardPCB milling is one of the most important aspects of PCB design and manufacture. If you get your PCBs made by a professional PCB assembly and manufacturing company, they will already mill the device before sending it to you.
However, if you subscribe to the DIY school of thought and want to mill it yourself, here are a few pieces of advice that we have for you.
What is PCB Milling?Before we begin, let’s discuss what PCB milling is so that we’re all on the same page. In its essence, milling is defined as the act of removing copper areas from a blank PCB board to create tracks and patterns. All these structures can be imported from a layout file which is essentially a digital circuit layout file.
While you might be wondering that etching is simpler than milling and can be used to achieve the same result, it’s important to understand that the latter fails when doing SMDs with a finer pitch. In these situations, milling is often your only choice!
Tips for Milling a PCB:Here are some tips that will make milling your PCB a breeze.
Tip #1 – Get the Right Mill:This one’s a no brainer; if you want to mill your PCB, then you will need to invest in the right mill. While the cost of most CNC mills may have been ridiculously high, in recent years these prices have plummeted and you can easily pick up a mill for as little as 350-400 USD.
Tip #2 – Choosing the Right Bits:Choosing the wrong bit for the job is often the most common mistake that inexperienced circuit designers make. While all the bits in your bit-case may look and feel exactly the same, these spearheads always have microscopic differences that could make or break your PCB.
So, before you select a bit for the milling process, it’s of the utmost importance that you check its diameter and angle of inclination. Failure to do so will result in a printed circuit board that has uneven pits and tracks.
Tip #3 – Auto-Leveling Is Key:Since we’re on the topic of uneven pits and tracks, a simple way of avoiding them is by using the auto-leveling tool in your milling software. It’s a little known fact that no matter how flat a printed circuit board may appear to the naked eye, all PCB boards have some curvature.
While that may sound trivial at first it’s important to understand that even if your PCB is slightly bent, your mill won’t be able to do its job properly and you will be left with a PCB with uneven tracks (as seen in this video).
Why Mill In the First Place?While we encourage people to create their own electrical solutions, it’s important to understand that, in some situations, doing so makes no financial sense. Such is the case with PCB milling because to mill your PCBs you need to invest hundreds of dollars in a CNC mill and also spend a large portion of your day creating the schematics.
This is why when it comes to creating custom printed circuit boards, you should always opt for the services of top PCB assemblers. If you want to use PCBs in your electrical and electronic devices then we at Topscom PCB Assembly team would love to help!
We’re one of the top electronic assembly companies in the world and are considered experts in the world of SMT PCB fabrication and assembly. So, pick up the phone and get in touch with us for premium quality PCBs.