Appearance inspection apparatus and appearance inspection method of electronic components

An appearance inspection method for inspecting components soldered to a printed circuit board, said appearance inspection method comprising:

• (a) setting a viewing field of a camera provided above the printed circuit board and an emission area of a laser beam emitted from a laser oscillator to overlap each other,
• (b) moving the printed circuit board horizontally relative to said camera and said laser oscillator to position a first component soldered to the printed circuit board in the viewing field and the emission area,
• (c) acquiring image data of the first component using the camera and storing said image data in a memory,
• (d) measuring a height of a measuring point using the laser beam and storing the measured height in the memory,
• (e) maintaining said printed circuit board stationary until both step (c) and step (d) have been performed,
• (f) moving the printed circuit board horizontally relative to said camera and said laser oscillator to position a next component soldered to the printed circuit board in said viewing field and said emission area, and
• (g) judging whether an appearance quality of said first component and the solder using the stored measured height and the stored image data from said memory while performing step (f).

An appearance inspection apparatus for inspecting an electronic component adhered by solder on a substrate comprising:

• a camera for observing said electric component, positioned above the substrate, wherein an optical axis of the camera is perpendicular to the substrate, said camera having a viewing field and said electric component being located in said viewing field,
• a light source which emits an illuminating light onto the substrate, said illuminating light used by said camera for observing said component,
• a light emitter which generates a measuring light,
• an optical device positioned between the substrate and the camera, said optical device directing the measuring light onto the substrate by reflecting the measuring light from the light emitter,
• a scanning means positioned between the light emitter and the optical device for scanning the measuring light so that the measuring light scans an emission area on the substrate which overlaps the viewing field of the camera, and
• a plurality of photo sensors radially positioned around the optical axis of the camera for receiving the measuring light by a reflection from the substrate.

An appearance inspection method for inspecting components soldered on a substrate comprising the steps of:

• (a) acquiring an image of the substrate at a camera having an optical axis perpendicular to the substrate,
• (b) emitting a measuring light along the optical axis of the camera to a measuring point inside of a viewfield of the camera,
• (c) receiving, at a photo sensor, the measuring light reflected by the substrate,
• (d) judging a quality of a positioning and a soldering of the electronic component to the substrate using said image data and a signal from the photo sensor,
• (e) maintaining the substrate stationary until both step (a) and step (c) have been performed, and
• (f) moving the substrate relative to the camera so that a next electronic component is positioned for inspection,
• wherein the viewfield of the camera and a viewfield of the measuring light overlap.