Laser trimming
Laser trimming is a process in which electronic components and circuits are balanced and trimmed via laser-induced changed. In general, individual components – e.g. thick-film or thin-film resistors in a circuit – are modified with a laser such that the individual resistance value or the entire circuit is balanced. Proper guidance of this form of laser trimming process is only possible with a suitable laser system that can be controlled with pulse precision via a connection to the measuring technology. The laser system is combined with an imaging system to very precisely position the laser beam.
In practice, various cutting forms are used for trimming. The frequently used serpentine cut features a large trim range and provides substantial benefits when used to replace mechanical trimmers. In addition to the smaller size and reduced cost in comparison to trimming potentiometers, laser-trimmed resistors boast improved long-term stability. Common trimming applications include aligning the characteristic curves of electronic sensors, adjusting proximity sensors to match their nominal switching distances or linearising measuring amplifiers in medical and measuring technology.
Typical materials
- Thick-film resistors
- Thin-film resistors