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EP-4377757-B1 - METHOD FOR AUTOMATICALLY DETECTING DEFECTS IN THE COMPONENTS OF A CIRCUIT BOARD

EP4377757B1EP 4377757 B1EP4377757 B1EP 4377757B1EP-4377757-B1

Inventors

  • GOUDARD, Sylvain
  • GRENIER, Thomas

Dates

Publication Date
20260513
Application Date
20220722

Claims (13)

  1. A method (100, 200, 300, 400) for automatically detecting defects on components of an electronic board, said method (100, 200, 300, 400) comprising the following steps: - acquisition (102) of at least one image (103), so as to form a so-called overall image, of said electronic board, said overall image (103) comprising at least one component of said board, and - analysis (104), by a previously established first model (303), of said overall image (103) to determine a position of at least one component of said electronic board located on said overall image (103); and for at least one determined position (105): ∘ acquisition (106) of at least one image (107), referred to as a detailed image, of said component located at said position (105), and ∘ analysis (108), by a previously established second model (305), of said detailed image (107) to determine the presence of defects on said component; characterized in that - the previously established first model (303) comprises a neural network trained in a supervised manner with a database, the so-called training component database, comprising images of components belonging to electronic boards, said first model (303) taking the overall image (103) as input, and - the previously established second model (305) comprises a neural network trained in a supervised manner with a database, the so-called training defect database, comprising images of previously cataloged defects of components, said second model (305) taking a position of at least one component as input.
  2. The method (100, 200, 300, 400) according to claim 1, wherein the analysis step (104) by the first model (303) comprises: - an identification step (202) of at least one component of said electronic board, and, - for each identified component, a step (204) of providing the at least one position (105) of said component.
  3. The method (100, 200, 300, 400) according to claim 1 or 2, wherein the overall image (103) is an image of said electronic board as a whole or an image of a part of said electronic board.
  4. The method (100, 200, 300, 400) according to any of the preceding claims, wherein the detailed image (107) is an image of the at least one component as a whole or an image of a part of the at least one component.
  5. The method (100, 200, 300, 400) according to any of the preceding claims, wherein the position (105) of at least one component comprises the position of a microcontroller, and/or the position of a passive component, and/or the position of a digital signal processor present on said electronic board.
  6. The method (100, 200, 300, 400) according to any of the preceding claims, wherein the analysis step (108) by the second model (305) is arranged to detect defects, for example among bridges, dry solder joints, surface defects, pollutants, and/or their acceptability, on the at least one component of said electronic board.
  7. The method (100, 200, 300, 400) according to any of the preceding claims, wherein the position (105) of the at least one component comprises Cartesian coordinates of the at least one component.
  8. The method (300, 400) according to any of the preceding claims, comprising a preliminary phase (302), referred to as the first preliminary phase, carried out prior to said step (102) of acquiring the overall image (103), comprising the following steps: - acquisition (304) of a multitude of overall images of electronic boards comprising at least one component, - storage (306) of said overall images on a database.
  9. The method (300, 400) according to any of the preceding claims, comprising a preliminary phase (308), referred to as the second preliminary phase, carried out prior to the acquisition (106) of said detailed image (105), comprising the following steps: - acquisition (310) of a multitude of detailed images on electronic boards, - storage (312) of said detailed images on a database.
  10. A computer program comprising instructions executable by a computer device which, when they are executed, implement all the steps of the method (100, 200, 300, 400) according to any of the preceding claims.
  11. A computer device (500, 601) comprising means configured to implement all the steps of the method (100, 200, 300, 400) according to any of claims 1 to 9.
  12. Equipment (600) for automatically detecting defects on components of an electronic board, characterized in that it comprises: - a computer device (500, 601) comprising means configured to implement all the steps of the method (100, 200, 300, 400) according to any of claims 1 to 9, - at least one acquisition means (610) arranged to acquire images of said electronic board and/or components belonging to said electronic board.
  13. The equipment (600) according to the preceding claim, wherein the acquisition means (610) is mobile and/or wherein the electronic board is immobile and/or wherein the at least one component of said electronic board is immobile.

Description

technical field The present invention relates to a method for the automatic detection of defects on components of an electronic board. It also relates to a computer device implementing such a method. The field of the invention is that of autonomous fault detection on electrical board components. State of the art We know of methods for detecting defects on an electronic circuit board. These methods are functional but present problems: automation. Indeed, these processes require, for each electronic board to be checked, an operator's intervention to detect and identify defects; Accuracy is important because even when an operator intervenes, they use filters or masks to visually highlight defects. Detection accuracy therefore depends on the filters used and also on the operator's judgment, specifically their concentration and skill. Forgetting to use a particular filter can thus lead to errors and/or missed defects. ease of use, as the process for detecting defects may be more or less easy for an operator new to defect detection to implement; and The time required for implementation is significant because the detection steps require operator intervention and manual operations. Therefore, the time needed to complete the process can depend on the operator and their ability to visually detect defects. Consequently, the time required for each electronic board checked can vary and be tedious. This can also discourage manufacturers from performing these steps, leading to a decrease in the average quality of the boards. Thus, conventional automatic optical inspection machines need to be programmed specifically according to a type of electronic card and, during its implementation, a verification of the analysis results must be carried out by an operator in order to give a sanction. US 2018/0276811 A1 discloses a two-step method for detecting defects on an electronic board. CHEONG LEONG KEAN ET AL: "Defects and Components Recognition in Printed Circuit Boards Using Convolutional Neural Network "discloses a method for detecting defects on an electronic board involving a neural network. One objective of the present invention is to remedy at least one of the aforementioned drawbacks. Another objective of the invention is to provide a method for the automatic detection and/or identification of different types of defects on components of an electronic board that is more autonomous and does not depend on human know-how. Another objective of the invention is to provide a method for the automatic detection and/or identification of defects on components of an electronic board that is more precise and/or configurable according to criteria for the acceptability of defects. Another objective of the invention is to provide a method for the automatic detection and/or identification of defects on components of an electronic board that is easier to implement. Another objective of the invention is to provide a faster method for the automatic detection and/or identification of defects on components of an electronic board. Another objective of the invention is to provide a method for the automatic detection and/or identification of defects on components of an electronic board without it being necessary to know a priori their location on the electronic board. Description of the invention The invention makes it possible to achieve at least one of the aforementioned goals by a method according to claim 1. Thus, the process according to the invention uses fully automated steps that do not require the intervention or know-how of an operator. The process is therefore more autonomous. Furthermore, the analysis steps of the process according to the invention both use a self-contained model that requires no operator intervention. Consequently, the process according to the invention is more accurate, easier to implement, and faster. Furthermore, acquiring both an overall and a detailed image facilitates its ease and speed of implementation. Specifically, the overall image can be of lower quality than the detailed image because it is used for component detection. Conversely, the detailed image focuses on a single component, allowing for quick and easy verification of defects on that component. In general, the method of the invention makes it possible to detect defects on components without it being necessary to know the board being analyzed. The overall image can correspond to an image acquired using an acquisition means such as a camera or a photographic device, or result from a reconstruction of several images acquired with such an acquisition means and then assembled. The process may include a step for communicating the defects or the result of the analysis step by the second model. This communication may consist of, or include, a list of the defects with their position and/or name and/or their acceptability in a table, if, for example, defects are detected in the analysis step by the second model. The list of defects can be adapted or filtered