Metrology system for analyzing panel misregistration in a panel manufacturing process and providing appropriate information for adjusting panel manufacturing processes

• US 5,206,820 A
• Filed: 08/31/1990
• Issued: 04/27/1993
• Est. Priority Date: 08/31/1990
• Status: Expired due to Fees

• Current Assignee: Viasystems Technologies Corp. LLC (TTM Technologies Incorporated)
• Original Assignee: AT&T, Inc.
• Inventors: Simons, Everett, Potechin, Jamey, Steines, Richard C., Ammann, Hans H., Kovacs, Richard F., Micks, Henry B. Jr., Cheng, Kwokming J., Tetz, John G.
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US07/576,304
• Time in Patent Office: 970 Days
• Field of Search: 364/559, 382/8
• US Class Current: 702/185
• CPC Class Codes: H05K 13/0061 Tools for holding the circuit boards during processing; handling transport of printed circuit boards
• CPC Class Codes: H05K 13/081 Integration of optical monitoring devices in assembly lines; Processes using optical monitoring devices specially adapted for controlling devices or machines in assembly lines
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A metrology system to analyze panel misregistration in a panel manufacturing process includes a software controlled system which checks defined panel parameters on the four corners of a panel and related artwork for processing with a master pattern etched on a glass reference with a machine vision measuring system. The panel or artwork being checked is positioned by panel center registration means to align the center of the panel with the center of the master pattern. Displacement and rotational differences are entered under software control into a data base and analyzed by a stored program intelligent analyses system into a plurality of parameters based on a parameter model which permits an analysis of the cause of the misregistration.

Claims

1. Apparatus for inspecting pattern registration in a panel manufacturing process, comprising:

a panel locating mechanism using panel centered positioning techniques;

a pattern marking corners of the patterns with working fiducials symmetric about a center of the pattern;

a transparent reference surface with reference fiducials marked on the surface and positioned symmetric about a center of the reference surface;

superimposing a pattern, with corners of the pattern marked with working fiducials symmetric about a center of the pattern, on the reference surface using the panel locating mechanism for positioning the pattern on the reference surface;

a machine vision measurement apparatus positioned for measuring displacements of the working fiducials from the reference fiducials;

a computer system coupled to receive the measured displacements from the machine vision measurement apparatus and including memory for storing the measured displacements in a data base, and including an output display apparatus for displaying results of the inspecting of pattern registration;

wherein the improvement comprises;

the computer system including a stored program control including instructions for decomposing the measured displacements stored in the data base into a set of rigid body transition parameters and material deformation transition parameters;

the stored program control of the computer system including further instructions for transforming the rigid body parameters and material deformation parameters, associated with a plurality of patterns of a sample lot being analyzed, into a set of multiple composite distortion parameters related to a plurality of patterns, including average values and deviation values of the rigid body parameters and average values and deviation values of the material deformation parameters;

the computer system including memory including stored numerical control limits for each of the multiple composite distortion parameters;

the stored program control including further instruction for comparing each of the multiple composite distortion parameters with the numerical control limits;

the stored program control including instructions for assigning causes of misregistration to specific operations and conditions of the panel manufacturing process by assigning a probably cause associated with each of the multiple composite distortion parameters that exceed the critical threshold limits; and

the output display apparatus communicating the the results of inspecting pattern registration and displaying any pattern misregistrations and displaying the causes assigned for these misregistrations to operative personal.

2. Apparatus for inspecting pattern registration as claimed in claim 1;

the improvement further comprising;

the stored program being operative for decomposing the measured displacements into rigid body and deformation parameters by solving polynomial expansion series equations.

3. Apparatus for inspecting pattern registration as claimed in claim 2;

the improvement further comprising;

memory for storing measured displacements from data of an aggregate of sample lots; and

the stored program control being operative for converting the measured displacements from data of an aggregate of sample lots into extended period parameters for analyzing trends of registration in the panel manufacturing process.

4. A panel inspection and measurement system, comprising;

A panel measurement apparatus, including;

a transparent reference surface with reference fiducials inscribed therein and having a reference center and a reference axis with respect to the reference fiducials;

positioning apparatus for locating the panel with a pattern including pattern fiducials dimensionally related to the reference fiducials and to a pattern center and pattern axis of the panel so that registration of the reference fiducials and pattern fiducials is related to registration of the reference center and reference axis to the pattern center and pattern axis;

a vision type measuring system for measuring displacements of the pattern fiducials from the reference fiducials;

means for collecting data and output means for displaying data on the displacements measured;

wherein the improvement comprises;

means for displacement cause evaluation, including a data storage means, a data processor means and a memory means including a stored program for evaluating the displacements in terms of causes of the displacements, and an output means including;

means for transforming the displacements measured into a first set of primary parameters restructuring the displacements into rigid body displacements and material deformed displacements,

means for transforming the parameters into a second set of advanced parameters related to displacements of the pattern center and pattern axis of the panel from registration with the reference pattern and reference axis surface; and

means for analyzing the individual terms of the advanced parameters to generate further output on the output means and printing out a graph to suggest probable causes of the misregistration.

5. In a panel inspection and measurement system in which panels are analyzed for misregistration a method of determining causes of the misregistration, comprising the steps of:

including pattern fiducials as part of a overall pattern on a panel and the panel having an axis and center locus about which the overall pattern and pattern fiducials are referenced;

placing the panel having the pattern fiducials on a transparent reference surface having corresponding reference fiducials and an axis and center about which the reference fiducials are referenced;

positioning the panel on the transparent reference surface by engaging tooling features of the panel with a locating system associated with the transparent reference surface and operative to align the axis and center of the panel with the axis and center of the transparent reference surface;

measuring displacements of the pattern fiducials from the reference fiducials by vision measuring techniques;

collecting data on displacements measured;

displaying the data on displacements measured;

storing the displacement measurements in a data storage system;

wherein the improvement comprises the steps of;

transforming the displacement measurements into a first set of primary parameters restructuring the displacements into rigid body displacements and material deformed displacements,

transforming the parameters into a second set of advanced parameters related to displacements of the pattern center and pattern axis of the panel from registration with the reference pattern and reference axis surface;

analyzing the individual terms of the advanced parameters to generate an output to suggest probable causes of the misregistration; and

displaying and printing out a graph representing the probable causes as a part of a readout of the displacement measurements.