Kulicke and Soffa Industries, Inc.

Quad Systems Corporation

George Michael Berkin

Asuri S Raghavan

Raymond E Foran

Gautam N Shah

Michael Negin

Mark B Soffa

Joseph Chlebda

Jeffrey Clarke

Richard F Heady

Ralph Mayer

Thomas F Schueller

Mansur F Pagdiwala

The present invention relates to controls for a multi-zone reflow oven. In the present invention a plurality of infra red thermal scanners are located at critical points along the path which a substrate passes in a reflow oven so as to generate an actual solder paste time/temperature profile as a substrate passes through the zones of the reflow oven. The actual temperature of the solder paste is determined at critical zones for generating feedback control signals. The time/temperature profile is stored for transfer to a different reflow oven so as to effect the identical solder paste time/temperature curve on the same or a different oven. Temperature deviations from the points on the solder paste time/temperature curve are calculated and control signals are generated for producing feedback signals that are applied to the controllers of the belt drive motor, the convection fan motors as well as the heating elements in the heating blocks of the vertical zone heaters to control and effect an actual and desired optimum solder paste time/temperature profile.

Method and apparatus for controlling a time/temperature profile of a reflow oven

Method and apparatus for controlling a time/temperature profile inside

A method of operating a pattern recognition apparatus comprises generating a plurality of sub pixel sub signatures from a reference signature, wherein the sub pixel sub signatures correspond to fractional pixel (sub pixel) positions. A target sub signature is compared to each of the sub pixel sub signatures to determine the relative placement of a target object to within a fraction of a pixel.

Pattern recognition apparatus and method

A system and method for determining the condition and location of an electronic die on a die holding means is disclosed. The system includes means for illuminating the die and means for generating a video image in which the appearance of the die is enhanced relative to the die holding means. This is accomplished by providing a sensing means for sensing primarily only that light reflected from the candidate die. Means for converting the video image into a digital image and processing said digital image to identify the edges of the die is also disclosed. More particularly, means for generating digital data representing the video image, means for defining a corridor in said digital image, said corridor having a width and a length, and means for processing the digital image to obtain a signature element within the digital data are provided. A signature element is the widthwise summation of data within the corridor at a point along the lengthy of the corridor and represents the relative blackness or whiteness in a particular region of the digital image. Also provided are control means for defining a corral within the digitized image of the die, means for obtaining a black count within the corral, and means for analyzing the black count to determine the condition of the die. Means for automatically selecting the light intensity and gray level used in generating the digital image is provided.

Pattern recognition system

A wire bonding apparatus and method incorporating a pattern recognition system wherein there is stored, in a teach mode, signatures representing a pre-determined point on a chip to be bonded, the signatures being obtained at respective 90.degree. locations of the pedestal which carries the chip. Automatic re-calibration provides for rotating the pedestal to each of four 90.degree. apart spaced angles and finding the respective recorded signatures and the corresponding positions, and calculating the true center of rotation as a function of the four positions thus found. A specialized algorithm is used for correcting error which may be introduced if the chip is not rotated at precisely 90.degree. intervals during the process of finding the respective signatures. The system carries out re-calibration automatically every N packages bonded.

Bonding apparatus with means and method for automatic calibration using

An improved pattern recognition system is disclosed which converts rows and columns of digitized video signal elements indicative of light intensity falling on a camera into integrated signatures, one for each of two orthogonal directions. Signatures corresponding to effectively rotated images may also be provided. Portions of the signatures having the most useful information contained therein are selected by comparison with subsets of the total signatures in a teach mode. In a run mode, the thus selected sub signatures are compared with snapshot signatures of a target object, such as integrated circuit dice, for precise location of corresponding portions of the target object.

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Yardley, PA, United States of America

George Michael Berkin