[54] PROFILES TO INSURE PROPER HEATING FUNCTION
[75] Inventors: Mark J. Cowell, San Carlos; Thomas
H. McGaffigan, Half Moon Bay;
James C. Swift, Menlo Park, all of
Calif.
[73] Assignee: Metcal, Inc., Menlo Park, Calif.
[21] Appl. No.: 692,987
[22] Filed: Apr. 29,1991
Related U.S. Application Data
[63] Continuation-in-part of Ser. No. 365,300, Jun. 13, 1989, abandoned.
[51] Int. CI.5 B23K 1/00
[52] U.S. CI 219/85.22
[58] Field of Search 219/85.12, 85.16, 85.19,
219/85.22, 497, 498, 501
[56] References Cited
U.S. PATENT DOCUMENTS
3,991,297 11/1976 Ammann 219/85.16
4,224,744 9/1980 Siegel et al 219/85.22
4,256,945 3/1981 Carter et al. .
4,317,980 3/1982 Goodrich et al. .
4,390,954 6/1983 Manning .
4,580,026 4/1986 Stol .
4,595,816 6/1986 Hall et al. .
4,698,774 10/1987 Abe et al. .
4,720,623 1/1988 DiCesare et al 219/501
OTHER PUBLICATIONS
"Automatic Laser Inspection System for Solder Joint Integrity Evaluation", Institute for Interconnecting and Packaging Electronic Circuits, Vanzetti, pp. 1-11, May 1984.
"Users Guidelines for Automatic Solder Joint Inspec-
tion Systems", Institute for Interconnecting and Pack-
aging Electronic Circuits, Jul. 1986.
"Signature Analysis Unit", Proel Systems USA.
Primary Examiner—Clifford C. Shaw
Attorney, Agent, or Firm—Howard L. Rose
[57] ABSTRACT
A peak power measurement as a function of various system parameters is made to determine completion of a proper heating operation; in one embodiment by measuring peak power delivered to a level as a function of temperature within a specified time period for a specific load; and in another embodiment by the plot of peak power and ramp-up and ramp-down levels as a function of time.
25 Claims, 6 Drawing Sheets
