Automated laminography system for inspection of electronics

A method of detecting solder defects at a solder connection between electrical components on circuit boards comprising the steps of:

• producing a cross-sectional image of a cutting plane of said solder connection;
• defining a region of said cross-sectional image corresponding to said solder connection;
• calculating an average image intensity for said region;
• and
• comparing said average image intensity to a predetermined threshold value.

A method of detecting solder bridging defects at a solder connection between electrical components on circuit boards comprising the steps of:

• producing a cross-sectional image of a cutting plane of said solder connection;
• calculating a series of differential image intensity values along a border which surrounds said cross-sectional image of said solder connection;
• comparing the magnitude of said differential image intensity values to a predetermined threshold value;
• and
• identifying locations along said border wherein the magnitude of said differential image intensity value exceeds said predetermined threshold value.

A method of detecting solder bridging defects at a solder connection between electrical components on circuit boards comprising the steps of:

• producing a cross-sectional image of a cutting plane of said solder connection;
• calculating solder thickness along a border which surrounds said cross-sectional image of said solder connection;
• comparing said solder thickness to a solder thickness threshold value;
• and
• identifying locations along said border wherein said solder thickness exceeds said solder thickness threshold value.

A method of detecting solder bridging defects at a solder connection between electrical components on circuit boards comprising the steps of:

• producing a cross-sectional image of a cutting plane of said solder connection;
• defining a partition between at least two of said solder connections;
• analyzing image intensity values along said partition;
• and
• identifying locations along said partition which are detected as solder bridges as a result of said analysis.

A method of inspecting an electrical connection between electrical components mounted on a printed circuit board comprising the steps of:

• producing a cross-sectional image of a cutting plane of said electrical connection which lies in a plane that is adjacent to a surface of said printed circuit board;
• searching said cross-sectional image for predetermined features of said electrical connection;
• and
• performing predetermined analytical tests on said cross-sectional image.