Pattern recognition system and method for digital printed circuit board assembly

A method for assembling a printed circuit board using digital printing and pattern recognition, the method comprising:

• fixing a printed circuit board onto a target platform;
• adjusting a laser source with respect to the target platform;
• capturing one or more images of the printed circuit board using an imaging system;
• extracting coordinates of shapes and areas of interest on the printed circuit board from the captured images, the areas of interest being locations where solder paste is to be deposited;
• locating and identifying one or more special colored markers on the printed circuit board using pattern recognition applied to the captured images;
• determining a position and orientation of the printed circuit board on the target platform based on the identified markers;
• placing a donor substrate on the target platform;
• aligning the donor substrate with the printed circuit board;
• coating the donor substrate with a solder paste layer;
• depositing solder paste from the donor substrate onto the areas of interest on the printed circuit board via digital laser printing;
• placing the printed circuit board in a component placement machine;
• depositing one or more electronic components onto the printed circuit board at predetermined positions;
• and
• performing thermal annealing to bond the solder paste and secure the electronic components to the printed circuit board.

A pattern recognition system for the assembly of printed circuit boards by digital printing, comprising:

• a pulsed laser source;
• an optical path configured to guide a laser beam through a series of mirrors;
• a two-lens system configured to magnify the laser beam to a size determined by the diameter of an entrance hole of a two-dimensional galvanometric system and to parallelize the beam before entering the galvanometric system;
• an attenuating beam setup, as part of a controllable printing setup comprising a transparent carrier coated with solder paste;
• a receiver substrate;
• a stepper motor configured for movement in the Z direction;
• an adjustable XY translation stage configuration;
• and
• an imaging setup for real-time visualization, comprising a CMOS camera, an achromatic lens, a dichroic mirror positioned along the beam propagation axis of the pulsed laser source, and an LED source configured to illuminate a donor substrate;
• wherein the imaging setup is configured to capture images of the printed circuit board to be assembled;
• and
• wherein the pattern recognition system is configured to:
• extract coordinates of the shapes and areas of interest on the printed circuit board where solder paste is to be deposited;
• locate and identify special markers on the captured images of the board using pattern recognition methods;
• and
• determine, for solder paste deposition, the position and orientation of the physical object to be targeted on a target platform used to fix the printed circuit board.