Material inspection
AssigneeMV Research Limited
InventorsMark D. Owen, Adrian Boyle, Peter Conlon
Life of this patent
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Abstract
An inspection station (6) has a ring of 370 nm LEDs (24) for low-angle diffuse illumination of flux. This stimulates inherent fluorescent emission of the flux without the need for flux additives or pre-treatment. A CCD sensor (20) detects the emission. An image processor generates output data indicating flux volume according to a relationship between emission intensity and volume over the surface of the flux. Intensity non-uniformity indicates either height non-uniformity or hidden voids, both of which give rise to defects after application of solder paste and reflow. The inspection is particularly effective for pre solder application flux inspection.
Claims28
A method of inspecting a dielectric material deposited on a substrate in an electronics production process, the method comprising the steps of:
- (a) directing radiation excitation at the material to cause radiation emission by inherent fluorescence of the material,
- (b) detecting the emission, and
- (c) processing said emission to generate output data;
- characterised in that,
- step (b) comprises determining emission intensity data, and step (c) comprises processing said intensity data to generate output data indicating volume of the material according to a relationship between emission intensity and material volume.
An inspection system comprising:
- a radiation source (24) for directing radiation excitation at a wavelength to cause inherent fluorescent emission in a dielectric material,
- a sensor (21) for detecting inherent fluorescent emission, and
- an image processor comprising means for determining emission intensity data from the detected emission and for generating output data indicating volume of the material according to a relationship between said emission intensity and material volume.
Dependencies are inferred from the claim text.