Off-axis illumination assembly and method

An imaging system for capturing an image of a surface of an electronic substrate, the imaging system comprising:

• a housing;
• a camera assembly coupled to the housing, the camera assembly being adapted to capture an image of the electronic substrate;
• an on-axis illumination assembly coupled to the housing, the on-axis illumination assembly being adapted to generate light substantially along a first axis generally perpendicular to the surface of the electronic substrate;
• and
• an off-axis illumination assembly coupled to the housing, the off-axis illumination assembly being adapted to generate rays of light substantially along a second axis extending at an angle with respect to the first axis.

A method for dispensing solder paste onto a surface of an electronic substrate, the method comprising:

• delivering an electronic substrate to a stencil printer;
• performing a print operation to print solder paste onto the surface of the electronic substrate;
• illuminating at least one area of the electronic substrate with on-axis light that extends substantially along a first axis generally perpendicular to the surface of the electronic substrate;
• illuminating the at least one area of the electronic substrate with off-axis light that extends substantially along a second axis extending at an angle with respect to the first axis;
• and
• capturing an image of the at least one area of the electronic substrate.

A stencil printer for depositing solder paste onto a surface of an electronic substrate, the stencil printer comprising:

• a frame;
• a stencil coupled to the frame, the stencil having a plurality of apertures formed therein;
• a dispenser coupled to the frame, the stencil and the dispenser being constructed and arranged to deposit solder paste onto the electronic substrate;
• an imaging system constructed and arranged to capture an image of the electronic substrate, the imaging system comprising
• a camera assembly,
• an on-axis illumination assembly adapted to generate light substantially along a first axis generally perpendicular to the surface of the electronic substrate, the on-axis illumination assembly including an optical path adapted to reflect light between the on-axis illumination assembly, the electronic substrate, and the camera assembly, and
• means for generating rays of light along a second axis extending substantially at an angle with respect to the first axis;
• and
• a controller coupled to the imaging system, the controller being constructed and arranged to control movement of the imaging system to capture an image.