In the PCB design world, there's a hidden hero often overlooked by beginners—a seemingly insignificant dot, yet it can transform a product from frequent rework to first-pass success, and from cost overruns to efficient mass production.

It's the mark. Today, let's discuss in plain language why it's essential to place a mark after PCB design, and how to avoid pitfalls.

Don't underestimate this tiny dot! It serves five key purposes; missing one can be a real problem.

Some may ask, "My PCB design is all correct, so can I do without this dot?" Absolutely not! While the mark may seem simple, it's actually a guiding light throughout PCB manufacturing and assembly. Without it, the rest of the process becomes a complete mess.

1. Achieve "zero deviation" in component placement, eliminating the need for frustrating manual labor.
Currently, mainstream SMT (surface mount technology) placement relies on machines to automatically place components on PCBs. But how does the machine know where to place the components? The answer is markers.

By recognizing these markers, the machine can accurately locate the position and angle of the PCB, automatically adjusting even if the PCB is slightly tilted. Without markers, either manual alignment is required (an excruciatingly slow process) or the machine misplaces the components, ultimately resulting in a scrapped product.

Even in manual assembly scenarios, markers help operators quickly find the correct position, making it much more convenient than measuring components from a blueprint.

2. Shorten Manufacturing Cycle Time and Double Efficiency
The first step in PCB manufacturing is determining the board's position. Before markers, workers had to manually measure and mark with a ruler. This was fine for a single board, but for mass production, positioning alone took a significant amount of time.

With markers, things are different—the machine can instantly "spot" the markers and complete positioning in seconds, significantly reducing pre-production time. This improves production efficiency and enables faster product delivery—isn't that a real competitive advantage?

3. Reduce rework waste and directly reduce costs.

Manual operations inevitably result in errors: for example, misaligned component placement or misaligned boards during soldering. These mistakes can lead to scrapped PCBs, which not only costs money but also delays production.

Marking points allow for more accurate automated machine operations, reducing the likelihood of incorrect placement and soldering errors at the source. Don't underestimate this; in mass production, even saving 10% of scrapped boards can save significant costs.

4. No reflow oven rollovers, significantly reducing defect rates.

After component placement, PCBs are heated in a reflow oven to melt the solder and secure the components. This process places particularly high demands on alignment—if the boards are not properly positioned, components may shift after heating, or even result in defective solder joints.

With marking points, the reflow oven automatically aligns the PCBs, ensuring that each board is heated with precise positioning and timing. This significantly reduces defect rates and eliminates the time it takes to sort out and repair defective boards.

5. Ensure product stability for greater peace of mind
Whether it's a mobile phone, computer, or industrial equipment, PCB stability directly determines its lifespan. Marking points ensure that every PCB is manufactured and assembled to standard standards—no components are placed straight on some boards, or crooked on others.

With improved consistency, product stability and reliability are naturally higher, significantly reducing the probability of subsequent failures.

How to place marking points? 3 key details, even beginners can get it right the first time

Now that you understand the importance of marking points, the next step is to figure out how to place them correctly. The method is actually very simple. Just remember these three key points:

1. Style & Size: Follow the "1-2-3" standard and don't make any changes.
Marking points aren't just random circles; there's a fixed "golden ratio":

The center is a 1mm diameter pad (equivalent to the core of the small circle);
The outer layer is a 2mm diameter solder mask window (to expose the pad for easier machine recognition);
The outermost layer is a 3mm diameter conductor (which can be circular or polygonal, depending on personal preference).

Just stick to these dimensions and don't try to come up with your own ideas—after all, the factory's machines are tuned to this standard, and changing them might cause issues with recognition.

2. Positioning: Prioritize the "component side"; three points are sufficient.
Which side to place: If the PCB has components on only one side (single-sided layout), place them only on that side; if there are components on both sides, place them on both sides.

How many points to place: Three points per side are sufficient; more would be redundant. Specific Location: Ideally, place it in a corner of the board, about 3mm from the edge—this allows for easy machine recognition without affecting the layout of other components.

Final reminder: Don't wait until you make a mistake to remember this!

Many novice PCB designers, caught up in the circuit design and layout, forget to place the mark. Only when the factory reports "unable to produce" or "placement error" do they go back and make changes, which not only wastes time but can also delay the project.

In reality, designing the mark isn't complicated. Spending a few minutes placing it according to standard procedures can save countless headaches later. Remember: the "last mile" of PCB design often lies in these seemingly insignificant details.