Inaccurate mounting and severe misalignment? Teach you to solve the vision system failure of Samsung surface mount technology (SMT) machines
Many friends who are engaged in SMT production have ever had such an experience: the surface mount technology (SMT) placement machine is running without alarming, and the feeder is feeding normally, but the placement is always "inaccurate". Sometimes it deviates by 0.2mm, and sometimes it just leans to the side. The PCB board is stuck all over the place, as if it hasn't woken up yet.
At this point, the problem is mostly not with the suction nozzle or the mounting pressure, but rather - there is something wrong with the visual system.
In today's article, let's talk about the common faults of the vision system of Samsung surface mount technology (SMT) machines, their diagnosis methods, as well as how to repair and adjust them, so that you won't be at a loss when encountering misalignment!
I. What exactly does the visual system do in a surface mount technology (SMT) placement machine?
Let's do a brief science popularization first: Before the surface mount technology (SMT) machine places things, it doesn't rely on "guessing" to place them, but rather on the camera to identify and locate the positions of components and PCB pads.
Samsung surface mount technology (SMT) machines typically have two sets of vision systems:
-
Component Vision Recognition System
Be responsible for confirming what you are sucking up and whether the direction and pin orientation are correct.
-
PCB Positioning Vision System (Board Vision)
It will look for the positioning points of the PCB (usually MARK points) to ensure that the position will not be off when pasting.
If either of these two systems malfunctions, your mounting accuracy will be "delayed".
Mounting misalignment
Ii. Misalignment During Mounting? Start by checking from these places!
Now let's talk about the "practical process". If there is inaccurate mounting on site, you can check it in this order:
1. MARK point recognition fails or is incorrect
Performance: The entire board is misaligned, and all components are crooked
Inspection method
- Check the machine operation log to see if it reports "Mark Fail" or "Mark Offset".
- Manually take a MARK image to see if there are any stains, scratches or excessive reflection.
- Check the brightness of the MARK light to see if it is too strong or too dim.
Solution
- Clean the surface of the PCB board;
- Adjust the lighting brightness and Angle;
- Reset the MARK point parameter when necessary.
2. The photo of the component is blurry and the direction is misidentified
Manifestation: Some components are pasted in the wrong direction and are significantly misaligned
Inspection method
- Check whether the image taken by the component is clear.
- Whether the wrong packaging type or rotation Angle has been selected;
- Check whether the suction nozzle is deformed or clogged.
Solution
- Replace or clean the suction nozzle;
- Adjust the height for visual photography;
- Check the component library data (whether the Angle is set in reverse).
Focal length of the visual camera
3. The focal length of the visual camera or the lens is loose
Performance: Blurry image edges and high failure rate of recognition
Inspection method
- Open the visual debugging screen and observe the image clarity.
- Shake the lens to see if it is loose.
- Check if the screws are loose.
Solution
- Refocus or change the lens;
- Secure the camera and the stand.
- Perform a camera Calibration.
4. Aging or abnormal brightness of the lighting module
Manifestation: The visual image is too bright/too dark or half bright and half dark
Inspection method
- Observe whether the brightness of the image is uniform;
- Manually adjust whether the brightness test takes effect;
- If conditions permit, the usage duration of the lighting LED can be retrieved.
Solution
- Replace the lighting board;
- Readjust the brightness parameters;
- Adjust the Angle of the light source to prevent reflection or shadows.
5. Incorrect software parameter Settings
Manifestation: Some components are off-center, while others are completely normal
Inspection method
- View the visual recognition patterns of each component in the mounting program;
- Are there any incorrect templates or encapsulated information used?
- Whether multiple MARK points are enabled but the parameters are inconsistent.
Solution
- Reset the component recognition rules;
- Check whether the program was copied from the old project;
- Check whether the MARK recognition strategy of each PCB is consistent.
Maintenance of the visual system
Iii. Prevention is more important than Repair: Maintenance Suggestions for the visual system
To ensure the mounting is always accurate, regular maintenance is indispensable
- Clean the surface of the camera and lens every day (gently wipe with an alcohol swab)
- Check the brightness and uniformity of the light source once a week
- Conduct a MARK point recognition test once a month
- Have a complete visual calibration every three months
Also, it is suggested that when you encounter inaccurate mounting, do not just focus on the suction nozzle and the feeder. The visual system is always one of the key links.
Don't panic if problems arise. Just follow the steps
Although the vision system of the surface mount technology (SMT) machine sounds quite high-end, its principle is actually very simple - it's just "taking photos + recognizing images". As long as you adjust the image clearly and set the recognition logic correctly, the mounting accuracy will naturally improve.
Equipment is not a god; it also needs "care" and "physical examination".
In the future, when you encounter misalignment during mounting, don't smash the machine right away. First, check if the visual system is still "awake".
I hope this article can help you quickly solve those troublesome offset problems. If you have more on-site experience or questions, you are also welcome to leave a message for exchange. Let's make progress together!
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