ultra thin multilayer (PCB) (UTM)

Ultra-thin multilayer (UTM) is the name given to a construction class for extremely thin printed circuit boards in microfine conductor technology that is much thinner than normal multilayer printed circuit boards. The vias also have a much smaller diameter.

Four-layer ultra-thin multilayer printed circuit board (UTM)

The crucial difference lies in the laminates for the inner layers. These are a maximum of 50 µm thin. Assuming 5 µm, 9 µm or 17 µm for the copper lamination and 110 µm for each prepreg, a four- layer UTM PCB is less than 300 µm, a six-layer less than 400 µm and an eight-layer less than 500 µm. In contrast, an 8-layer standard PCB is 1.5 mm thick. The vias of UTM PCBs have a diameter of only 150 µm.