Method and apparatus for inspecting solder portions

• US 5,495,424 A
• Filed: 02/24/1994
• Issued: 02/27/1996
• Est. Priority Date: 04/18/1990
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tokura, Nobufumi
• Primary Examiner(s): Ramirez, Ellis B.
• Application Number:
  US08/200,960
• Time in Patent Office: 733 Days
• Field of Search: 364/552, 364/507, 364/525, 382/141, 382/144, 382/145, 382/146, 382/150, 348/86, 348/90, 348/92, 348/126, 348/129, 356/237, 324/538
• US Class Current: 702/82
• CPC Class Codes: G01N 21/95684 Patterns showing highly reflecting parts, e.g. metallic elements

Abstract

A solder portion is inspected as follows. An image of the solder portion is obtained. The image of the solder portion is collated with a plurality of predetermined reference patterns corresponding to different solder portion types respectively. A type of the solder portion is identified in response to a result of the collation. A decision is made as to whether the solder portion is satisfactory or unsatisfactory in response to the identified type thereof.

Claims

1. A method of inspecting a solder portion, comprising the steps of:

obtaining an image of the solder portion;

collating the image of the solder portion with a plurality of predetermined reference patterns corresponding to different solder portion types respectively;

identifying a type of the solder portion in response to a result of the collating step; and

deciding whether the solder portion is satisfactory or unsatisfactory in response to the identified type thereof.

2. The method of claim 1, wherein the collating step and the identifying step comprise calculating rates of matching of the image of the solder portion with the reference patterns respectively, selecting a maximum matching rate from among the calculated matching rates, and identifying the type of the solder portion as being equal to the type corresponding to the maximum matching rate.

3. A method of inspecting a solder portion, comprising the steps of:

obtaining an image of the solder portion;

calculating rates of matching of the image of the solder portion with predetermined reference patterns corresponding to different solder portion types respectively;

selecting a maximum matching rate from among the calculated matching rates;

comparing the maximum matching rate with a predetermined reference matching rate;

identifying a type of the solder portion as being equal to the type corresponding to the maximum matching rate when the maximum matching rate is greater than the reference matching rate; and

deciding whether the solder portion is satisfactory or unsatisfactory in response to the identified type thereof.

4. The method of claim 3, further comprising the step of using the image of the solder portion as a new reference pattern corresponding to a new solder portion type when the maximum matching rate is equal to or smaller than the reference matching rate, the new solder portion type corresponding to a gray state between a satisfactory state and an unsatisfactory state.

5. An apparatus for inspecting a solder portion, comprising:

means for obtaining an image of the solder portion;

means for collating the image of the solder portion with a plurality of predetermined reference patterns corresponding to different solder portion types respectively;

means for identifying a type of the solder portion in response to a result of the collating by the collating means; and

means for deciding whether the solder portion is satisfactory or unsatisfactory in response to the identified type thereof.

6. The apparatus of claim 5, wherein the collating means comprises a pattern matching circuit.

7. A method of inspecting a solder portion, comprising the steps of:

obtaining an image of the solder portion;

deciding which of predetermined reference patterns corresponding to different solder portion types respectively is most similar to the image of the solder portion, wherein each of the reference patterns corresponds to either a satisfactory solder portion state or an unsatisfactory solder portion state;

identifying a type of the solder portion as being equal to the type corresponding to the reference pattern most similar to the image of the solder pattern; and

deciding whether the solder portion is satisfactory or unsatisfactory in response to the identified type thereof.

8. An apparatus for inspecting a solder portion, comprising:

means for obtaining an image of the solder portion;

means for deciding which of predetermined reference patterns corresponding to different solder portion types respectively is most similar to the image of the solder portion, wherein each of the reference patterns corresponds to either a satisfactory solder portion state or an unsatisfactory solder portion state;

means for identifying a type of the solder portion as being equal to the type corresponding to the reference pattern most similar to the image of the solder pattern; and

means for deciding whether the solder portion is satisfactory or unsatisfactory in response to the identified type thereof.