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Lighting Method for Automatic Solder Bond Inspection

IP.com Disclosure Number: IPCOM000099330D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Nakano, N: AUTHOR

Abstract

This article describes a lighting method and an apparatus for automatically inspecting defects of solder bonds of electronic components mounted on a printed circuit board. The lighting method has three major features: 1. The operation is synchronized with the vertical synchronization signal of a camera. 2. A matrix of LEDs (Light Emitting Diodes) is used as a light source. 3. LED matrix panels are controlled independently by a

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Lighting Method for Automatic Solder Bond Inspection

       This article describes a lighting method and an apparatus
for automatically inspecting defects of solder bonds of electronic
components mounted on a printed circuit board.
    The lighting method has three major features:
    1.   The operation is synchronized with the vertical
    synchronization signal of a camera.
    2.   A matrix of LEDs (Light Emitting Diodes) is used as a
    light source.
    3.   LED matrix panels are controlled independently by a

      computer.

                            (Image Omitted)

      LED panels 11-18 are disposed octagonally in the lower portion
of the apparatus.  Four cameras 40-43, such as CCD cameras, are
provided in the upper portion of the apparatus. A printed circuit
board on which electronic components are mounted is placed in the
apparatus and positioned such that an electronic component whose
solder bonds are to be inspected is at the center of the octagon.
One of the four cameras 40-43 is selected, and three LED panels, one
below the selected camera and two neighbors, are lit for a short
period in synchronism with the vertical synchronization signal of the
camera.  For example, when the camera 40 is selected, LED panels 11,
12, and 13 are lit.

      By this method, defects of solder bonds of electronic
components can be detected easily and rapidly.  Also,
three-dimensional inspection of solder b...