Title:
INSPECTION METHOD FOR OUTSIDE APPEARANCE OF SEMICONDUCTOR DEVICE AND ITS INSPECTING DEVICE
Document Type and Number:
Japanese Patent JP3190173
Kind Code:
B2
Abstract:
PURPOSE: To stably detect a defective part irrespective of size and surface state by automatically deciding threshold for binarizing density, and computing the volume of the defective part on the surface of a package based on the thereshold.
CONSTITUTION: The picked up 12 image of the mold resin package of a semiconductor product 10 is processed 14. Namely, the density of each picture element of a variable density image which has been binarized in an image and has a size within a set up domain is analized. An accumulated density distribution histogram is produced on the number of picture elements at each of the densities, and threshold Lth for binarizing density is automatically decided on the basis of both the histogram and the number of mold cavity picture elements from which the surface of the set up package is judged to be defective. A mask image M setting up the picture element not more than-the threshold Lth as the maximum density and a mask image Mf being the filter-processed mask image M are formed, and a certain point P in the variable density image is subtracted from the threshold Lth to obtain an image Q. Logical product operation is carried out between the images Q, Mf, and the density value at each picture element point of an obtained defective image R is accumulatedly computed in each of two-dimensional directions, X, Y of the image to compute the volume of the defective part for judging quality on a basis of the set up threshold.
Inventors:
Kimihiko Kohno
Application Number:
JP13057993A
Publication Date:
July 23, 2001
Filing Date:
June 01, 1993
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
G01N21/88; G01N21/93; G01N21/956; G06T1/00; G06T5/00; G06T7/00; G01B11/24; H01L21/66; (IPC1-7): G01N21/88; G01B11/24; G01N21/956; G06T1/00; G06T7/00; H01L21/66
Domestic Patent References:
| JP4107946A | ||||
| JP1284743A | ||||
| JP57137978A |
Attorney, Agent or Firm:
Takehiko Suzue