Inspecting apparatus of mounting state of component or printing state of cream solder in mounting line of electronic component

• US 5,991,435 A
• Filed: 05/31/1996
• Issued: 11/23/1999
• Est. Priority Date: 06/30/1992
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsujikawa, Toshihiko, Mizuoka, Seiji, Nagamoto, Masao
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): MEHTA, BHAVESH M
• Application Number:
  US08/657,785
• Time in Patent Office: 1,271 Days
• Field of Search: 382/141, 382/145-147, 382/150, 348/86, 348/87, 348/90, 348/94, 348/95, 348/125, 348/126
• US Class Current: 382/147
• CPC Class Codes: G06T 2207/30141 Printed circuit board [PCB]
• CPC Class Codes: G06T 2207/30152 Solder
• CPC Class Codes: G06T 7/0006 using a design-rule based approach
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: H05K 1/0269 for visual or optical inspection
• CPC Class Codes: H05K 2203/163 Monitoring a manufacturing process
• CPC Class Codes: H05K 2203/167 Using mechanical means for positioning, alignment or registration, e.g. using rod-in-hole alignment
• CPC Class Codes: H05K 3/1233 Methods or means for supplying the conductive material and for forcing it through the screen or stencil

Abstract

An inspecting apparatus is arranged on an electronic component mounting line for inspecting whether a mounting state of the component mounted on a printed circuit board by a mounting apparatus in a precedent process or a printing state of a cream solder by a cream solder printing apparatus in a precedent process is non-defective or defective. The inspecting apparatus includes an input device for taking data of the mounting state of the component to be inspected or the printing state of the cream solder to be inspected, a comparing device for comparing the data of the mounting state or the printing state input through the input device with an absolute decision criterion having a predetermined allowable range to decide whether the mounting state or the printing state is non-defective or defective and an operating state criterion which is within and narrower than the allowable range of the absolute decision criterion, and a deciding device for deciding an operating state of the mounting apparatus or the cream solder printing apparatus in the precedent process based data within the absolute decision criterion and outside the operating state criterion. An automatic position setting device is operable for setting a relative position of a metal mask and the printed circuit board. Further, a method for inspecting printing states of cream solders includes setting a window in a picked up image, performing color extraction of an element within the window and detecting predetermined patterns, calculating positions and/or areas of the elements, and deciding a defective or nondefective state by comparing the calculated position and/or area with respective reference data.

Claims

1. An inspecting apparatus arranged on an electronic component mounting line for inspecting an assembly state of an article obtained from a precedent process of the mounting line, the precedent process being a process for printing a cream solder on a position of a printed circuit board, and the assembly state being a cream soldering state of the printed circuit board which is inspected by measurement data of a positional shift amount of the cream solder and measurement data of an area of the cream solder, said inspecting apparatus comprising:

an image pick-up device for obtaining an image of the article;

means for generating the measurement data of the positional shift amount of the cream solder and the measurement data of the area of the cream solder of the article to be inspected from the image obtained by said image pick-up device;

a comparing means for comparing each of the measurement data of the positional shift amount and the measurement data of the area with a corresponding absolute decision criterion defining a corresponding first predetermined allowable range of the respective measurement data, wherein the first predetermined allowable range of the absolute decision criterion corresponding to the positional shift amount represents a range where the positional shift amount of the cream solder is allowable and the first predetermined allowable range of the absolute decision criterion corresponding to the area represents a range where the area of the cream solder is allowable, and for comparing each of the measurement data of the positional shift amount and the measurement data of the area with a corresponding operating state criterion defining a corresponding second predetermined allowable range of the respective measurement data which is within and narrower than the corresponding first predetermined allowable range, so that a range inside of the first predetermined allowable range and outside of the second predetermined allowable range of the operating state criterion corresponding to the positional shift amount represents a prediction range for predicting defective generation in positional shift amount of the cream solder and a range inside of the first predetermined allowable range and outside of the second predetermined allowable range of the operating state criterion corresponding to the area represents a prediction range for predicting defective generation in area of the cream solder;

a deciding means for deciding whether the assembly state of the article is defective based on whether the measurement data of the positional shift amount and the measurement data of the area are within the corresponding first predetermined allowable range, and for deciding an operating state of the precedent process of the mounting line based on measurement data of the positional shift amount and the measurement data of the area which are within the corresponding first predetermined allowable range and outside the corresponding second predetermined allowable range; and

an output means for outputting a correction signal based on the measurement data of the positional shift amount and the measurement data of the area which are within the corresponding first predetermined allowable range and outside the corresponding second predetermined allowable range, wherein the correction signal is operable for correcting the positional shift amount and/or the area of the cream solder in the precedent process.

2. An inspecting method for inspecting printing states of cream solders printed on a printed circuit board through color image processing with the use of an image picked up by an image pick-up device, said method comprising:

setting a window for a region in the picked-up image where each cream solder is to be printed;

performing color extraction of each cream solder within the window and then detecting patterns within the window of the cream solders, based on the color extraction, of areas not smaller than a preset value;

calculating positions of the cream solders from a sum of positions of centers of gravity of the detected cream solder patterns according to an area ratio of each detected cream solder pattern; and

deciding whether the printing states of the cream solders are non-defective or defective by comparing the calculated position with a reference position of each cream solder.

3. An inspecting method for inspecting printing states of cream solders printed on a printed circuit board through color image processing with the use of an image picked up by an image pick-up device, said method comprising:

setting a window for a region in the picked-up image where each cream solder is to be printed;

performing color extraction of each cream solder within the window and then detecting patterns within the window of the cream solders, based on the color extraction, of areas not smaller than a preset value;

calculating the areas of the cream solders from a sum of areas of the detected cream solder patterns; and

deciding whether the printing states of the cream solders are non-defective or defective by comparing the calculated area and a reference area of the cream solder.

4. An inspecting method for inspecting printing states of cream solders printed on a printed circuit board through color image processing with the use of an image picked up by an image pick-up device, said method comprising:

setting a window for a region in the picked-up image where each cream solder is to be printed;

performing color extraction of each cream solder within the window and then detecting patterns within the window of the cream solders, based on the color extraction, of areas not smaller than a preset value;

calculating positions of the cream solders from a sum of positions of centers of gravity of the detected cream solder patterns according to an area ratio of each detected cream solder pattern;

deciding whether the positions of the cream solders are non-defective or defective by comparing each calculated position and a reference position of each cream solder;

calculating the areas of the cream solders from a sum of areas of the detected cream solder patterns; and

deciding whether the areas of the cream solders are non-defective or defective by comparing each calculated area and a reference area of each cream solder.

5. An inspecting method for inspecting printing states of cream solders printed on a printed circuit board through color image processing with the use of an image picked up by an image pick-up device, said method comprising:

setting a window for lands of the printed circuit board in the picked-up image;

performing color extraction of each land of the printed circuit board within the window and then detecting patterns within the window of the cream solders of the lands of the printed circuit board based on the color extraction;

detecting pseudo patterns of the cream solders of areas not smaller than a preset value from the detected patterns of the lands;

calculating positions of the cream solders from a sum of positions of centers of gravity of the detected pseudo cream solder patterns according to an area ratio of each detected pseudo cream solder pattern; and

deciding whether the printing states of the cream solder are non-defective or defective by comparing each calculated position and a reference position of each cream solder.

6. An inspecting method for inspecting printing states of cream solders printed on a printed circuit board through color image processing with the use of an image picked up by an image pick-up device, said method comprising:

setting a window for lands of the printed circuit board in the picked-up image;

performing color extraction of each electrode of the printed circuit board within the window and then detecting patterns within the window of the cream solders of the lands of the printed circuit board based on the color extraction;

detecting pseudo patterns of the cream solders of areas not smaller than a preset value from the detected patterns of the cream solders of the lands of the printed circuit board;

calculating the areas of the cream solders from a sum of the areas of the detected pseudo cream solder patterns; and

deciding whether the cream solders are non-defective or defective by comparing each calculated area and a reference area of each cream solder.

7. An inspecting method for inspecting printing states of cream solders printed on a printed circuit board through color image processing with the use of an image picked up by an image pick-up device, said method comprising:

setting a window for lands of the printed circuit board in the picked-up image;

performing color extraction of each land of the printed circuit board within the window and then detecting patterns within the window of the cream solders of the lands of the printed circuit board based on the color extraction;

calculating positions of the cream solders from a sum of positions of centers of gravity of pseudo cream solder patterns according to an area ratio of each pseudo cream solder pattern of an area not smaller than a preset value based on the detected patterns of the cream solders of the lands of the printed circuit board;

deciding whether the positions of the cream solders are non-defective or defective by comparing each calculated position and a reference position of each cream solder;

calculating areas of the cream solders from a sum of areas of the detected pseudo cream solder patterns; and

deciding whether the areas of the cream solders are non-defective or defective by comparing each calculated area and a reference area of each cream solder.

8. An inspecting method for a mounting line for inspecting an assembly state of an article obtained from a precedent process of the mounting line, the precedent process being a process for printing a cream solder on a position of a printed circuit board, and the assembly state being a cream soldering state of the printed circuit board which is inspected by measurement data of a positional shift amount of the cream solder and measurement data of an area of the cream solder, said method comprising:

using an image pick-up device to obtain an image of the article;

generating the measurement data of the positional shift amount of the cream solder and the measurement data of the area of the cream solder of the article from the image obtained by the image pick-up device;

comparing each of the measurement data of the positional shift amount and the measurement data of the area with a corresponding absolute decision criterion defining a corresponding first predetermined allowable range of the respective measurement data, wherein the first predetermined allowable range of the absolute decision criterion corresponding to the positional shift amount represents a range where the positional shift amount of the cream solder is allowable and the first predetermined allowable range of the absolute decision criterion corresponding to the area represents a range where the area of the cream solder is allowable, and comparing each of the measurement data of the positional shift amount and the measurement data of the area with a corresponding operating state criterion defining a corresponding second predetermined allowable range of the respective measurement data which is within and narrower than the corresponding first predetermined allowable range, so that a range inside of the first predetermined allowable range and outside of the second predetermined allowable range of the operating state criterion corresponding to the positional shift amount represents a prediction range for predicting defective generation in positional shift amount of the cream solder and a range inside of the first predetermined allowable range and outside of the second predetermined allowable range of the operating state criterion corresponding to the area represents a prediction range for predicting defective generation in area of the cream solder;

deciding whether the assembly state of the article is defective based on whether the measurement data of the positional shift amount and the measurement data of the area are within the corresponding first predetermined allowable range, and deciding an operating state of the precedent process of the mounting line based on measurement data of the positional shift amount and measurement data of the area which are within the corresponding first predetermined allowable range and outside the corresponding second predetermined allowable range; and

outputting a correction signal based on the measurement data of the positional shift amount and the measurement data of the area which are within the corresponding first predetermined allowable range and outside the corresponding second predetermined allowable range, wherein the signal is operable for correcting the positional shift amount and/or the area of the cream solder in the precedent process.

9. An inspecting apparatus arranged on an electronic component mounting line for inspecting an assembly state of an article obtained from a precedent process of the mounting line, the precedent process being a process for mounting an electronic component on a position of a board, and the assembly state being a mounting state of the mounted component which is inspected by measurement data of a positional shift amount of the component, said inspecting apparatus comprising:

an image pick-up device for obtaining an image of the article;

means for generating the measurement data indicative of the assembly state of the article to be inspected from the image obtained by said image pick-up device;

a comparing means for comparing the measurement data of the assembly state with an absolute decision criterion defining a first predetermined allowable range of the measurement data, the first predetermined allowable range of the absolute decision criterion representing a range where the positional shift amount of the component is allowable, and for comparing the measurement data of the assembly state with an operating state criterion defining a second predetermined allowable range of the measurement data which is within and narrower than the first predetermined allowable range, so that a range inside of the first predetermined allowable range and outside of the second predetermined allowable range represents a prediction range for predicting defective generation in positional shift amount of the component;

a deciding means for deciding whether the assembly state of the article is defective based on whether the measurement data is within the first predetermined allowable range, and for deciding an operating state of the precedent process of the mounting line based on measurement data which is within the first predetermined allowable range and outside the second predetermined allowable range; and

an output means for outputting a correction signal based on measurement data which is within the first predetermined allowable range and outside the second predetermined allowable range, wherein the correction signal is operable for correcting the positional shift amount of the component in the precedent process.

10. An inspecting method for a mounting line for inspecting an assembly state of an article obtained from a precedent process of the mounting line, the precedent process being a process for mounting an electronic component on a position of a board, and the assembly state being a mounting state of the mounted component which is inspected by measurement data of a positional shift amount of the component, said method comprising:

using an image pick-up device to obtain an image of the article;

generating the measurement data indicative of the assembly state of the article from the image obtained by the image pick-up device;

comparing the measurement data of the assembly state with an absolute decision criterion defining a first predetermined allowable range of the measurement data, the first predetermined allowable range of the absolute decision criterion representing a range where the positional shift amount of the component is allowable, and comparing the measurement data of the assembly state with an operating state criterion defining a second predetermined allowable range of the measurement data which is within and narrower than the first predetermined allowable range, so that a range inside of the first predetermined allowable range and outside of the second predetermined allowable range represents a prediction range for predicting defective generation in positional shift amount of the component;

deciding whether the assembly state of the article is defective based on whether the measurement data is within the first predetermined allowable range, and deciding an operating state of the precedent process of the mounting line based on measurement data which is within the first predetermined allowable range and outside the second predetermined allowable range; and

outputting a correction signal based on measurement data which is within the first predetermined allowable range and outside the second predetermined allowable range, wherein the correction signal is operable for correcting the positional shift amount of the component in the precedent process.