Browse Prior Art Database

Automated Card Inspection

IP.com Disclosure Number: IPCOM000040246D
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 6 page(s) / 116K

Publishing Venue

IBM

Related People

Kishi, GT: AUTHOR [+2]

Abstract

An optical inspection system for identifying defective pins or leads as inserted through holes in cards and before soldering. The system identifies from a database the presence and type of lead for each hole in the card, and, accordingly, categorizes each hole of the card. The category selected determines a hierarchical set of routines for checking the optical image of the hole. Categorizing leads by component type allows different kinds of routines to be used to verify the presence of each type of lead. This means that each set of routines used to verify each type of lead can take maximum advantage of any preknowledge about the expected image from that type of lead. As an example, seven different categories may be used.

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Automated Card Inspection

An optical inspection system for identifying defective pins or leads as inserted through holes in cards and before soldering. The system identifies from a database the presence and type of lead for each hole in the card, and, accordingly, categorizes each hole of the card. The category selected determines a hierarchical set of routines for checking the optical image of the hole. Categorizing leads by component type allows different kinds of routines to be used to verify the presence of each type of lead. This means that each set of routines used to verify each type of lead can take maximum advantage of any preknowledge about the expected image from that type of lead. As an example, seven different categories may be used. The categories used are: Category 0 - "Hole" This category defines those locations on the printed circuit card whose images are expected to be empty holes. Empty holes appear as dark round areas in the center of a bright copper pad. A sample image follows: *********************************

*************** ***************

*********** ***********

********* *********

******* *******

****** hole ******

****** ******

******* *******

********* *********

*********** ***********

*************** ****pad********

********************************* Those routines used to verify the presence of an empty hole can take advantage of its shape and the fact that a certain region around the center of the hole should be dark. Category 1 - "Pin" This category defines those locations on the printed circuit card whose images are expected to be bright pins (such as module pins or axial pins). These pins are expected to be vertical in the hole; therefore, the bright pixels associated with the pin are expected within the boundaries of the hole. A sample image follows: *********************************

*************** ***************

*********** ***********

********* *********

******* XXXXX *******

****** XXpinXX ******

****** XXXXX ******

******* *******

********* hole *********

*********** ***********

*************** ******pad******

********************************* Those routines used to verify the presence of a pin can take advantage of its

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location (only the area around the center of the hole needs to be analyzed for the pin), or the fact that the pin changes the shape of the hole. Category 2 - "Top lead" This category defines those locations on the printed circuit card whose images are expected to be DIP (Dual Inline Package) leads clinched against the top of the holes. A sample image follows: *********************************

************XXXXXXXXX************

*********** XXleadXXX ***********

********* XXXXXXXXX *********

******* *******

****** ******

****** ******

******* *******

********* hole *********

*********** ***********

*************** ******pad******

********************************* Those routines used to verify the presence of top DIP leads can take advantage of their location (only...