Trimming process depends on a variety of parameters. These are: Laser power/pulse energy, trimming speed, laser pulse length, accuracy of the measurement devices, mechanical resolution of the scanning system, thermal stability of the laser system, measurement strategy and so on. Temperature drifts during laser processing and/or thermal expansion of the processed material may reduce the accuracy level. The acuracy that can be achieved by trimming is often better than what has been published in the media.
We are aware of these artefacts and took countemeasures to reduce these negative effects in our system.