PCB Laser Marking: Troubleshooting Common Problems

Is your PCB laser engraver's accuracy not up to standard? This article provides a detailed checklist for troubleshooting, which covers equipment parameter calibration, material compatibility testing, and daily maintenance. It will help you quickly identify common problems such as blurry or offset marks, and improve the efficiency and quality of PCB processing.

Why don't PCB laser marking machines meet the required precision standards?

If you encounter a problem with the marking effect, don't be in a hurry to suspect the quality of the equipment. Most of the time the problem is in the details of the settings or in operating habits.Let's take it step by step and begin by looking at the most common problems.

Check equipment parameter settings.

Is the focus accurate?

A laser focus error of as little as 0.1 millimeter can cause a blurred character.First a test plate was used to repeatedly adjust the focus to ensure that the light would fall on the surface of the material.If your equipment has an autofocus feature, don't forget to calibrate the sensor regularly.

Speed and power.

If the speed is too fast or the power too low, the engraving will not be deep enough.It is suggested that low-power gradient tests be conducted first to find the point where clarity and efficiency are in balance.Different materials require different parameters. For example, FR4 and aluminum have very different parameters.

The problem of materials compatibility.

The impact of surface treatment technology.

The reflectivity and absorbency of tin-plated, gold-plated and OSP boards is different.When encountering highly reflective materials, it is best to reduce the power and increase the number of scans to avoid melting the edges due to overload.

Flatness inspection.

If the PCB is warped by more than 0.5 mm, the laser will be out of focus.Before the material is loaded into the press, it is checked with a micrometer. In particular, large sheets and thin sheets (less than 1.0 mm thick) must be carefully checked.

Equipment maintenance and consumables.

Optical lens cleaning cycle.

The lens is checked at least once every eight hours.Use a single-direction wipe with alcohol and a lint-free cloth, and never use ordinary paper towels--the fibers will scatter the laser, which is a precision killer.

Calibration of the galvanometer system.

If the characters are deformed or misplaced, the galvanometer mirror is probably faulty.Equipment manufacturers generally provide calibration modules, which can be used to test the accuracy of the entire image every month.

Gas pressure monitoring.

When cleaning with nitrogen or compressed air, a pressure of 0.2-0.5 MPa is safe.If the pressure is too low, dust will obscure the laser, and if the pressure is too high, it will blow the board and cause misalignment.

It is also a factor that is often overlooked.

If the temperature in the workshop varies by more than 5 ℃, the wavelength of the laser may drift.If the humidity level remains above 60 % for a long period of time, the optical components will fog up.We recommend a temperature and humidity control system, especially during the rainy season.

If you follow this checklist, you can fix 90 % of all precision problems yourself.If the problem persists, remember to save any error messages and screenshots, so that you can save time when communicating with the manufacturer.