Five Common Causes of Misalignment in SMT and Their Solutions

The misalignment of electronic component markings can be caused by problems with machine calibration, loose fixtures, or material deformation.The book contains five of the most common problems and practical solutions, covering laser marking correction techniques, equipment maintenance points, and so on.

Why can't you get the markings on the parts in line?

Friends who do electronic component processing have probably all encountered this situation: The equipment parameters are clearly set correctly, but the marking position is still crooked, or even runs off the edge of the component.Here are five common problems and their solutions.

The equipment was not properly calibrated.

The laser head is off track.

After prolonged use, the laser marking machine's optical path system may become misaligned due to vibration or temperature changes.We recommend that you calibrate the machine every two weeks, especially when there are large temperature differences in the factory.

The coordinate system is all mixed up.

When changing the size of the component, under no circumstances should you directly use the same coordinates as before.After manually adjusting the XY axis origin, remember to test-fire 3-5 times with scrap material to confirm position and avoid a batch of defective products.

The problem was that the clamps were loose.

The suction cups don't have enough strength.

The easiest way to cause a misalignment is to have the components not be fixed firmly in place.Check the suction cups regularly for signs of wear and tear, and keep the air pressure above -0.6MPa.If the component is not standard, you can use a silicon pad to help secure it.

The mechanical locating pin has worn.

The alignment pins, which are inserted and removed several hundred times every day, develop gaps of 0.1-0.3 millimeters after about half a year.Keep two sets of pins of different sizes, and when you find that the parts are wobbling, replace them with the other set.

The material itself is causing trouble.

The base plate expands and contracts with temperature.

The difference in thermal expansion between the substrate and the material can be as much as 0.5 millimeters! The solution is simple: Use a preheat mode to stabilize the material for one minute, or use a pulse mode to disperse the heat.

Inconsistent surface coating.

If you are working with a dark color such as black, which absorbs a lot of the laser's energy, we suggest that you reduce the marking speed by 20 % and the power by 15 %.In this way, they can avoid burning and ensure accuracy in the positioning.

The parameters have to be just right.

The focus wasn't right.

Don't just look at the theoretical values in the equipment instruction manual. For components of different thicknesses, you need to use a caliper to measure them in reality and then adjust them according to the material's reflective properties.One little trick: put a dot in each corner of the screen. Whichever dot is clearest is the focal length you should use.

The power and speed are not matched.

The pursuit of speed can easily lead to a crash.For aluminum, he suggests using 800m / s and 35 % power, but for stainless steel, it should be reduced to 600m / s and 45 % power.The specific values can be found in the parameter tables provided by the material suppliers.

The operators must be careful.

The loading and unloading techniques are too rough.

Have you seen how the old masters of the craft can toss the material in the tray with one hand?The proper method is to handle the equipment gently, and after each load or unload let the machine reset itself.

Routine maintenance is ignored.

Don't ignore the details.By spending just five minutes at the end of each day wiping key areas with a dust-free cloth, the lifespan of equipment can be extended by several years.

If you keep a close eye on these key links, you can resolve the problem of label misalignment nine times out of ten.If you can't solve the problem, check the screws that hold the machine to the floor. Sometimes the machine is just not level!