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US4876455A Expired / Lapsed US ⏱️ 0.0 years remaining

Fiber optic solder joint inspection system

Assignee: Micron Technology Inc
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Filing: 1988-02-25
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Granted: 1989-10-24
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Expires: 2008-02-25
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Abstract

Abstract The invention is an automated solder joint inspection system for determining the quality of a specular soldered joint through examination of the shape of the joint surface using a series of point light sources and the associated highlight reflections from the joint surface. The light from the point light sources, which is directed toward the solder joint, is reflected in a pattern from the solder joint to an array of light responsive transducers, such as a camera, at a fixed location. Utilizing the intensity values from the light responsive transducer array, a binary grid map is generated for the reflections from each point light source. Using known surface features of solder joints along with curve fitting techniques, a series of grid maps may be mathematically interpreted to reconstruct the solder joint surface. A rule-based system, through comparison with acceptable solder joint surface features, evaluates and classifies the joint for an acceptability determination.

Inventors

  • 👤 Arthur C. Sanderson
  • 👤 Lee E. Weiss
  • 👤 Shree K. Nayar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 23:08
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95684; G01N21/8851; G01N2021/8887; G01N2021/95638; G01N2021/95646; G01N2201/00; G01N2201/10; G01N2201/102; G01N2201/108; G01N2201/1085

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 112 words
A method for determining the shape of an object having a specular surface comprising the steps of: (a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed configuration about a common site at which the object is placed for inspection; (b) viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface; (c) interpreting the light patterns to determine the surface orientation of points on the object surface; and (d) reconstructing the object surface profile using the surface orientations of points on the object.
Claim 2
Independent Claim 112 words
A method for determining the shape of an object having a specular surface comprising the steps of: (a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed configuration about a common site at which the object is placed for inspection; (b) viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface; (c) interpreting the light patterns to determine the surface orientation of points on the object surface; and (d) reconstructing the object surface profile using the surface orientations of points on the object.
Claim 3
Dependent Claim 38 words
The method of claim 1 wherein the projecting step utilizes light from a plurality of light sources which are arranged in a fixed arcuate two-dimensional configuration about a common site at which the object is placed for inspection.
Claim 4
Dependent Claim 37 words
The method of claim 1 wherein the projection step utilizes light from a plurality of light sources which are arranged in a fixed hemispherical configuration about a common site at which the object is placed for inspection.
Claim 5
Dependent Claim 61 words
The method of claim 1 wherein the interpreting step is comprised of converting an analog signal representing intensity into a digital signal and utilizing a threshold value to eliminate signals produced by light not directly reflected from the object surface, thereby producing a series of binary signals indicating whether or not a surface reflects light from specific point light source locations.
Claim 6
Dependent Claim 29 words
The method as defined in claim 1, further comprising, for evaluating the object, comparing the local surface features of the object profile to those of a desirable object profile.
Claim 7
Dependent Claim 25 words
The method as defined in claim 1 wherein viewing the object at the common site is done from a single direction at a fixed location.
Claim 8
Dependent Claim 30 words
The method as defined in claim 1 wherein viewing the object at the common site is done from a different singular direction at each of a plurality of fixed locations.
Claim 9
Dependent Claim 128 words
A non-contact inspection apparatus for determining the shape of an object having a specular surface comprising: (a) an array of point light sources spaced apart from one another in a fixed configuration about a common site at which the object is placed for inspection; (b) means for sequentially projecting each of the point light sources for emitting light toward the object; (c) a means for viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface; (d) a means for interpreting the light patterns to determine the surface orientation of points on the object; and (e) a means for reconstructing the object surface profile using the surface orientation of points on the object.
Claim 10
Dependent Claim 128 words
A non-contact inspection apparatus for determining the shape of an object having a specular surface comprising: (a) an array of point light sources spaced apart from one another in a fixed configuration about a common site at which the object is placed for inspection; (b) means for sequentially projecting each of the point light sources for emitting light toward the object; (c) a means for viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface; (d) a means for interpreting the light patterns to determine the surface orientation of points on the object; and (e) a means for reconstructing the object surface profile using the surface orientation of points on the object.
Claim 11
Dependent Claim 25 words
The apparatus of claim 8, wherein the point light sources of the array are spaced apart from one another in a fixed arcuate two-dimensional configuration.
Claim 12
Dependent Claim 24 words
The apparatus of claim 8, wherein the point light sources of the array are spaced apart from one another in a fixed hemispherical configuration.
Claim 13
Dependent Claim 48 words
The apparatus of claim 8, wherein the means for viewing the object at the common site for detecting light patterns is comprised of an array of light responsive transducers, such as a solid state camera, that produces an analog signal such as a voltage value for each transducer.
Claim 14
Dependent Claim 28 words
The apparatus of claim 8, further comprising means for comparing the local surface features of the object profile to those of a desirable profile to evaluate the object.
Claim 15
Dependent Claim 16 words
The apparatus of claim 12, wherein the object is a solder joint having a specular surface.
Claim 16
Dependent Claim 41 words
The apparatus of claim 8, wherein the means for viewing the object at the common site for detecting light patterns is comprised of an array of light responsive transducers oriented toward the object in a single direction at a fixed location.
Claim 17
Dependent Claim 46 words
The apparatus of claim 8, wherein the means for viewing the object at the common site for detecting light patterns is comprised of an array of light responsive transducers oriented toward the object from a different singular direction at each of a plurality of fixed locations.
Claim 18
Dependent Claim 127 words
A non-contact inspection apparatus for determining the shape of an object having specular surfaces comprising: (a) an array of point light sources spaced apart from one another in a fixed hemispherical configuration about a common site at which the object is placed for inspection; (b) means for sequentially activating each of the point light sources for emitting light toward the object; (c) means for detect the variety of light patterns caused by the reflections of light from each point light source at each location from the object surface; (d) means for interpret the series of light patterns to determine the surface orientation of points on the object; and (e) means for reconstruct the object profile using the surface orientation of a variety of points on the object.
Claim 19
Dependent Claim 127 words
A non-contact inspection apparatus for determining the shape of an object having specular surfaces comprising: (a) an array of point light sources spaced apart from one another in a fixed hemispherical configuration about a common site at which the object is placed for inspection; (b) means for sequentially activating each of the point light sources for emitting light toward the object; (c) means for detect the variety of light patterns caused by the reflections of light from each point light source at each location from the object surface; (d) means for interpret the series of light patterns to determine the surface orientation of points on the object; and (e) means for reconstruct the object profile using the surface orientation of a variety of points on the object.
Claim 20
Independent Claim 133 words
A method for determining the shape of an object having a specular surface comprising the steps of: (a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed hemispherical configuration about a common site at which the object is placed for inspection; (b) means for viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface wherein viewing the object at the common site is done from a single direction at a fixed location; (c) interpreting the light patterns to determine the surface orientation of points on the object surface; and (d) reconstructing the object surface profile using the surface orientations of points on the object.
Claim 21
Independent Claim 133 words
A method for determining the shape of an object having a specular surface comprising the steps of: (a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed hemispherical configuration about a common site at which the object is placed for inspection; (b) means for viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface wherein viewing the object at the common site is done from a single direction at a fixed location; (c) interpreting the light patterns to determine the surface orientation of points on the object surface; and (d) reconstructing the object surface profile using the surface orientations of points on the object.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-23 1993-04-24 1993-10-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-23 1997-04-24 1997-10-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-23 2001-04-24 2001-10-24 $7700.00 Window Closed / Lapsed

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