System and method for arithmetic operations for electronic package inspection

• US 6,201,892 B1
• Filed: 08/14/1998
• Issued: 03/13/2001
• Est. Priority Date: 02/26/1997
• Status: Expired due to Term

• Current Assignee: Microscan Systems Inc (Omron Corporation)
• Original Assignee: Acuity Brands, Inc.
• Inventors: King, Steven Joseph, Ludlow, Jonathan Edmund
• Primary Examiner(s): MEHTA, BHAVESH M
• Application Number:
  US09/134,397
• Time in Patent Office: 942 Days
• Field of Search: 382/149, 382/150, 382/132, 382/145, 382/141, 382/146, 382/147, 348/87, 348/126, 250/561, 250/559.34, 250/559.4, 356/237.1
• US Class Current: 382/149
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 21/95684 Patterns showing highly reflecting parts, e.g. metallic elements
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 2207/30152 Solder
• CPC Class Codes: G06T 7/0008 checking presence/absence
• CPC Class Codes: G06V 10/147 Details of sensors, e.g. sensor lenses fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19
• CPC Class Codes: H05K 13/0813 Controlling of single components prior to mounting, e.g. orientation, component geometry H05K13/0812 takes precedence

Abstract

An inspection system and method uses a first illumination apparatus to illuminate one or more features, such as solder balls on an electronic component or other protruding surfaces or features on an object being inspected. Once the object being inspected is illuminated, a first reflected image of the plurality of features is captured by an illumination detection device. The first reflected image is stored in an image buffer. The object being inspected is then illuminated by at least one additional illumination apparatus. Each additional illumination apparatus is selected so that it differs from the other illumination apparatuses in either geometrical arrangement, degree of diffusion or illumination characteristic. An additional reflected image of the object is then captured by the illumination detection device while the object is illuminated by each additional illumination apparatus. Each additional reflected image is also stored in an image buffer. Once at least two reflected images are captured and stored in the image buffer, they are combined by an image processor using at least one arithmetic operation to create a resulting image in which at least one selected feature is enhanced. The enhanced features appearing on the resulting image can then be inspected using additional image processing equipment using standard image analysis techniques.

Claims

1. An automated system for inspecting at least one selected feature on an object including a plurality of features, said system comprising:

an illumination detection device for capturing at least a first reflected image and one additional reflected image of said object including said at least one selected feature;

a first illumination apparatus for illuminating said object to produce said first reflected image, said first illumination apparatus comprising a ring illumination apparatus;

at least one additional illumination apparatus for illuminating said object to provide said at least one additional reflected image, said at least one additional illumination apparatus comprising an on-axis illumination apparatus; and

an image processor for combining said first and said at least one additional reflected image using at least one arithmetic operation to generate a resulting image wherein said at least one selected feature is enhanced.

2. The automated system for inspecting at least one selected feature on an object including a plurality of features as claimed in claim 1 further comprising image analysis equipment for analyzing said at least one selected feature.

3. The automated system for inspecting at least one selected feature on an object including a plurality of features as claimed in claim 1, wherein said at least one arithmetic operation is selected from the group consisting of addition, multiplication and division.

4. The automated system for inspecting at least one selected feature on an object including a plurality of features as claimed in claim 1, wherein said at least one arithmetic operation comprises at least one logical operation.

5. The automated system for inspecting at least one selected feature on an object including a plurality of features as claimed in claim 1, wherein said at least one arithmetic operation comprises at least one statistical operation.

6. The automated system for inspecting at least one selected feature on an object including a plurality of features as claimed in claim 1, wherein said at leat one arithmetic operation comprises a complex mathematical operation including a combination of mathematical operations.

7. A method of inspecting at least one selected feature on an object including a plurality of features comprising the steps of:

illuminating said object with a first illumination apparatus comprising a ring illumination apparatus to produce a first reflected image of said object;

capturing said first reflective image with an illumination detection device;

illuminating said object with at least one additional illumination apparatus, said at least one additional illumination apparatus comprising an on-axis illumination apparatus to produce at least one additional reflected image of said object;

capturing said at least one additional reflected image of said object with said illumination detection device; and

combining said first reflected image with said at least one additional reflected image using at least one arithmetic operation to enhance said selected feature.

8. The method of claim 7 further comprising the step of analyzing said resulting image with image analysis equipment to analyze said at least on selected feature.

9. The method of claim 7, wherein said image capture steps comprise capturing said reflected images with a charge coupled device (CCD) camera.

10. The method of claim 7, wherein said image capture steps comprise capturing said reflected images with a line scan camera.

11. The method of claim 7 wherein said illumination detection device is fixed in position with respect to said object while said first and said at least one additional reflected images of said plurality of features on said object are captured.

12. The method of claim 11, wherein said at least one arithmetic operation is selected from the group consisting of addition, multiplication and division.

13. The method of claim 11, wherein said at least one arithmetic operation comprises at least one logical operation.

14. The method of claim 11, wherein said at least one arithmetic operation comprises at least one statistical operation.

15. The method of claim 7, wherein said at least one arithmetic operation comprises a complex mathematical operation including a combination of mathematical operations.

16. An automated system for inspecting at least one expected feature on an object including a plurality of features, said system comprising:

a first illumination apparatus comprising a ring illumination apparatus for illuminating said object to produce a first reflected image of said plurality of features on said object;

at least one additional illumination apparatus for illuminating said object to provide at least a second reflected image of said plurality of features on said object, said at least one additional illumination apparatus comprising an on-axis illumination apparatus;

an illumination detection device for capturing said first reflected image and said at least one additional reflected image; and

an image processor for combining said first and said at least one additional reflected image using at least one arithmetic operation to generate a resulting image wherein said at least one expected feature is enhanced.

17. A method of inspecting at least one expected feature on an object including a plurality of features comprising the steps of:

illuminating said object with a first illumination apparatus to produce a first reflected image of said plurality of features on said object, said first illumination apparatus including a ring illumination apparatus;

capturing said first reflective image with an illumination detection device;

illuminating said object with at least one additional illumination apparatus, said at least one additional illumination apparatus comprising an on-axis illumination apparatus;

capturing said at least one additional reflected image of said object with said illumination detection device; and

combining said first reflected image with said at least one additional reflected image using at least one arithmetic operation to enhance said expected feature.