High-precision multilayer printed circuit board and 3d printing preparation method thereof

A 3D printing preparation method of a high-precision multilayer PCB, comprising the steps:

• S1. extruding a nanoscale metal slurry with shear thinning characteristics from an extrusion nozzle, to form a three-dimensional circuit layer on an upper surface of a substrate;
• S2. extruding the nanoscale metal slurry with shear thinning characteristics from the extrusion nozzle, to form a metal pillar at a preset position of the current three-dimensional circuit layer by stacking;
• S3. forming an insulating layer on an upper surface of the current three-dimensional circuit layer, and leading the corresponding metal pillar out of the formed insulating layer in advance by drilling a hole in the insulating layer and filling the drilled hole with the nanoscale metal slurry;
• S4. judging whether the current insulating layer acts as a top insulating layer;
• forming a pad layer on an upper surface of the current insulating layer and executing step S5 if yes;
• repeatedly executing steps S1 and S2 by using the current insulating layer as a new substrate, and executing step S6 if not;
• S5. connecting the metal pillar located on the corresponding three-dimensional circuit layer right below the current insulating layer or leading it out in advance and connecting to the pad layer, to complete the preparation of the multilayer PCB;
• and
• S6. connecting the metal pillar located on the corresponding three-dimensional circuit layer right below the current insulating layer or leading it out in advance and connecting to the current three-dimensional circuit layer, and returning to step S3.