Automated optical inspection apparatus

A machine vision apparatus for automating in-process inspection of device bonding, comprising:

• an image processing means for generating digital image signals from optically sensing apparatus,
• a bonding means, coupled to said image processing means, for placing a bond between said device and said supporting member,
• a means for activating said image processing means, coupled to said bonding means and said image processing means, for generating digital image signals corresponding to an optically sensed pre-bond view and an optically sensed post-bond view of said device located in said supporting member, wherein said image processing means further includes a means for creating a registration target window in said pre-bond view, and a means for creating a search area within said post-bond view, wherein said search area is at least as large as the area of the registration target window in said pre-bond view, together with a means for generating a plurality of comparison windows within said search area in said post-bond view, coupled to said search area creation means, wherein said comparison windows have dimensions equal to said registration target window in said pre-bond view, and
• a registration means, coupled to said activating means, for subtracting said post-bond view from said pre-bond view to identify a bond by generating an absolute difference value, said registration means further including a means for summing said absolute difference values, whereby each sum is stored as a difference metric, and
• a means for analyzing said difference metrics, coupled to said summing means, to find the difference metric representing the minimum difference, and
• an inspection means, coupled to said registration means, for verifying said bond.

A method for automating in-process inspection of device bonding, comprising:

• generating digital image signals corresponding to an optically sensed pre-bond view of a device which is to be bonded to a supporting member,
• placing a bond between said device and said supporting member,
• generating digital image signals corresponding to an optically sensed post-bond view of said device located in said supporting member,
• registering digital image signals corresponding to a bond by subtracting said post-bond view from said pre-bond view, and
• inspecting said bond.

A method for automating in-process inspection of device bonding, comprising:

• generating digital image signals corresponding to an optically sensed pre-bond view and an optically sensed post-bond view of a device which is to be bonded to a supporting member,
• placing a bond between said device and said supporting member,
• generating a subset of said pre-bond view to create a registration target window,
• generating a subset of said post-bond view to create a search area within said post-bond view, wherein said search area is at least as large as the area of the registration target window in said pre-bond view, and
• generating all possible image subsets in said search area having dimensions equal to said registration target window to create comparison windows within said search area in said post-bond view,
• subtracting said comparison windows in said post-bond view from said registration target window in said pre-bond view to generate an absolute difference value;
• summing said absolute difference value,
• storing each sum as a difference metric,
• analyzing said difference metrics to find the minimum difference, and
• inspecting the bond.

A method for locating a bond made between a device and a supporting member comprising:

• generating and analyzing digital image signals taken from an optical sensing apparatus which can create a pre-bond view of said device and supporting member and a post-bond view of said device and supporting member,
• placing a bond between said device and said supporting member,
• creating a registration target window in said pre-bond view, and a search area within said post-bond view, wherein said search area is at least as large as the area of the registration target window in said pre-bond view,
• generating a plurality of comparison windows within said search area in said post-bond view, such that said comparison windows have dimensions equal to said registration target window in said prebond view, and
• subtracting said post-bond comparison windows from said registration target window in said pre-bond view to generate an absolute difference value,
• analyzing said difference metrics to find the minimum difference.