YAG Laser Trimming


YAG laser trimming is a highly refined process for adjusting or correcting current paths in an electronic circuit, burning away segments of resistors to achieve optimum final electrical values.

ALT exploits high-speed YAG trimming systems with our exclusive technologies to trim both thick and thin film resistors, and embedded components, either in active or passive modes. We build probe cards on site, and perform frequent in-process testing with quick-turn, high-quality laser trimming.

Click here if you'd like to see our White Paper on Laser Trimming of Printed Resistors.



Laser trimming is the process of modifying the current through a resistor with a laser beam. This is accomplished by changing the shape of the resistor, essentially reducing width, and adding length to the travel path for the current. Depending on the design of the resistor, a number of standard trim types can be used, including the following:


There are two fundamental types of laser trimming; passive, and active or functional trimming. In passive trimming, a resistor or capacitor is trimmed to a specific value. This is accomplished by monitoring the resistance with a measurement device, and stopping the trim at the desired resistance value or percentage deviation from that value. In active or functional trimming, a circuit parameter such as voltage, current, frequency or phase is monitored and adjusted while the circuit is powered up.

Trimming is a down-stream process. This means that a client has already made significant development investment by the time trimming is required. ALT's exclusive processes and technologies are designed to maximize this investment by speeding up and increasing the accuracy of trim applications, utilizing the most suitable trim techniques and frequent in-process testing.

Support Processes

  • Active trim
  • Passive trim
  • YAG tie bar/Gold removal
  • Thick and thin film resistor trimming
  • Printed resistor trimming
  • Thermistor trimming
  • Step-and-repeat and single-circuit parts processing
  • Tight-tolerance trimming
  • Closed-loop resistor trimming through Active guarding


ALT specializes in processing a variety of substrate materials, sizes and thicknesses, including:

  • 96% Alumina
  • 99.6% Alumina
  • Aluminum nitride
  • Beryllium oxide
  • FR-4
  • FR-4: Prepreg materials
  • Thick Film
  • Thin Film

Please contact us with the material specifications you require. ALT can source materials, or process customer-supplied materials. In cases where material machining properties are not yet known, a fast turnaround, free trial can be arranged.