Non-Destructive Inspection Method

Abstract

A non-destructive inspection method for inspecting an object to be inspected using a plurality of different types of non-destructive inspection means is shown. The method includes the following, fixedly forming common marks that can be detected by any of the plurality of non-destructive inspection means on the object to be inspected; then detecting the object to be inspected including the marks by the plurality of non-destructive inspection means respectively; and comparing the detection results by the plurality of non-destructive inspection means using the marks as positional references.

Claims

1. A non-destructive inspection method for inspecting an object to be inspected using a plurality of different types of non-destructive inspection means, the method comprising: fixedly forming common marks that can be detected by any of the plurality of non-destructive inspection means on the object to be inspected; then detecting the object to be inspected including the marks by the plurality of non-destructive inspection means respectively; and comparing the detection results by the plurality of non-destructive inspection means using the marks as positional references.

2. The non-destructive inspection method according to claim 1, wherein peculiar parts are identified based on the detection result by one of the plurality of non-destructive inspection means and the peculiar parts are then detected intensively by the other non-destructive inspection means.

3. The non-destructive inspection method according to claim 1, wherein information other than the positional references is recorded in the marks and the information is read from the detection results of the non-destructive inspection means.

4. The non-destructive inspection method according to claim 1, wherein any two or more of X-ray radiographing means, magnetic field distribution measuring means, thermography radiographing means and hardness measuring means are included in the plurality of different types of non-destructive inspection means.

5. The non-destructive inspection method according to claim 4, wherein the plurality of different types of non-destructive inspection means comprise an X-ray Talbot radiographing apparatus as the X-ray radiographing means.

6. The non-destructive inspection method according to claim 1, wherein the plurality of different types of non-destructive inspection means comprise the magnetic field distribution measuring means, and raw materials constituting the marks comprise a magnetic substance.

7. The non-destructive inspection method according to claim 1, wherein the plurality of different types of non-destructive inspection means comprise the X-ray radiographing means and the magnetic field distribution measuring means, and raw materials constituting the marks comprise a substance with low X-ray transmission and a magnetic substance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1A is a schematic view of an object to be inspected (or detection result thereof) in a mark formation stage of a non-destructive inspection method according to an embodiment of the present invention.

[0026] FIG. 1B is a schematic view of an object to be inspected (or detection result thereof) in an inspection A stage of the non-destructive inspection method according to the embodiment of the present invention.

[0027] FIG. 1C is a schematic view of an object to be inspected (or detection result thereof) in an inspection B stage of the non-destructive inspection method according to the embodiment of the present invention.

DESCRIPTION OF EMBODIMENT

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The following description, however, is an embodiment of the present invention and not intended to limit the present invention.

[0029] An object to be inspected will be inspected using a plurality of different types of non-destructive inspection means. Examples of the plurality of different types of non-destructive inspection means include any two or more of X-ray radiographing means, magnetic field distribution measuring means, thermography radiographing means and hardness measuring means. In the present embodiment, a case will be described as an example, where an X-ray radiographing apparatus provided with X-ray radiographing means and a magnetic field distribution measuring apparatus provided With magnetic field distribution measuring means are used. The radiographing apparatus and the magnetic field distribution measuring apparatus are separate apparatuses and an object to be inspected moves between both apparatuses, and therefore the way the object to be inspected is placed with respect to origin coordinates of the respective apparatuses is not fixed.

[0030] At a stage of manufacturing a product (e.g., the aforementioned LIB), which becomes an object to be inspected 1, marks m1, m2 and m3 that can be detected by an inspection A and an inspection B are fixedly formed by printing or the like on the object to be inspected 1 (FIG. 1A), the inspection A (FIG. 1B) is then performed, and the inspection B (FIG. 1C) is performed.

[0031] For example, the X-ray radiographing apparatus performs a detection as the inspection A and the magnetic field distribution measuring apparatus performs a detection as the inspection B. In this case, a substance with low X-ray transmission and a magnetic substance are applied as the raw materials for constituting the marks. For example, ink containing a heavy metal that hardly transmits X-rays and a magnetic substance is applied in printing of the marks. An X-ray Talbot radiographing apparatus (see Patent Literature 2) is applicable as the X-ray radiographing apparatus. The X-ray Talbot radiographing apparatus provides higher contrast than that in normal X-ray inspection, and it is thereby possible to regard the substance with low X-ray transmission and the magnetic substance as identical substances. However, in general, adopting different substances for the substance with low X-ray transmission and for the magnetic substance makes it possible to select the substances with high properties respectively and improve their respective detectabilities. Therefore, even when the X-ray Talbot radiographing apparatus is applied, different substances may be used for the substance with low X-ray transmission and the magnetic substance.

[0032] Note that an MR sensor, MI sensor, TMR sensor (tunnel-type magnetic resistance sensor) or the like is applicable as the magnetic sensor mounted on the magnetic field distribution measuring apparatus. A TMR sensor (tunnel-type magnetic resistance sensor) with higher sensitivity is preferably applicable.

[0033] Now, results of detection on the object to be inspected 1 including the marks m1, m2 and m3 are detected by the preceding inspection A, for example, as shown in FIG. 1B. As shown in FIG. 1B, it is assumed that peculiar parts e1, e2 and e3 are detected in the object to be inspected 1. Examples of the peculiar parts include an abnormal location, a location suspected to be an abnormal location, a location requiring additional inspection or the like.

[0034] Next, results of detection on the object to be inspected 1 including the marks m1, m2 and m3 are detected by the inspection B as shown, for example, in FIG. 1C. As shown in FIG. 1C, it is assumed that peculiar parts f1 and f2 are detected in the object to be inspected 1.

[0035] Next, the detection results of the inspections A and B are superimposed using the marks m1, m2 and m3, and compared and examined in a correct positional relationship. That is, the position detection results of the inspection A and the inspection B are compared using the marks m1, m2 and m3 as references. For example, when plane coordinate axes XY are defined using the marks m1, m2 and m3 as references and the coordinates on the coordinate axes XY are assumed to be (x1, y1), an abnormality is determined by contrasting, comparing and examining the detection values of the coordinates (x1, y1) in the detection result of the inspection A and the detection values of the coordinates (x1, y1) in the detection result of the inspection B. For example, in FIGS. 1B and 1C, since the peculiar part e1 and the peculiar part f2 have the same coordinates, they are determined as abnormal locations.

[0036] Based on the detection results of the inspections A and B, a more specific fault analysis may be made by a further inspection C (e.g., cross section TEM). At that time, locations to be analyzed may be selected using the marks m1, m2 and m3 as positional references.

[0037] As described above, it is possible to accurately grasp and compare the identical locations on the object to be inspected among a plurality of different types of inspections, and efficiently analyze causes for defects and perform shipment inspections.

[0038] Information other than positional references may be recorded in the marks m1, m2 and m3. For example, the marks m1, m2 and m3 are formed with one-dimensional or two-dimensional barcodes and individual identification numbers are recorded. Each inspection apparatus reads the above information from marks (code recording media) included in the detection results. The information reading is made possible by using the marks as common marks that can be detected by any non-destructive inspection means. As described above, since individual identification numbers integrally exist in the detection results, the respective detection results of an identical individual can be easily and reliably compared.

[0039] The non-destructive inspection means can be any means other than the X-ray radiographing means or the magnetic field distribution measuring means as long as it can measure an in-plane distribution non-destructively and obtain a detection image as a result. Examples of such non-destructive inspection means may include thermography radiographing means for measuring a thermal distribution by thermography, hardness measuring means for inspecting hardness using a probe needle for each coordinate. In the case of thermography, marks may be formed using an ink material whose emissivity is different from that of the surface of the object to be inspected or in the case of the probe needle, marks may be formed using an ink material whose hardness is different from that of the object to be inspected.

[0040] The present invention may be implemented using a method whereby peculiar locations are detected by the preceding inspection A and the peculiar locations found in the inspection A are finely and intensively inspected by the subsequent inspection B. That is, this is the method whereby peculiar parts are identified based on detection results by one of the plurality of non-destructive inspection means, and then the peculiar parts are intensively detected by the other non-destructive inspection means. Intensively detecting peculiar parts refers to regarding only peculiar parts as objects to be detected or detecting the peculiar parts with higher detection resolution than that of the remaining region.

[0041] It may be possible to consider, for example, a method whereby peculiar parts e1, e2 and e3 identified from results of detecting the whole surface of the object to be inspected by the X-ray radiographing apparatus in the inspection A are more finely measured by the magnetic field distribution measuring apparatus in the inspection B. X-ray radiographing can capture images of the whole surface at a time and detect the peculiar parts in a short time, whereas magnetic field distribution measurement adopts a scheme of performing measurement while scanning the measurement head, which takes more time if the area of the object to be inspected is wide. In such a case, the method of finely detecting only the peculiar parts found in X-ray radiographing using the magnetic field distribution measuring apparatus can shorten the inspection time.

[0042] As described above, when inspecting an object to be inspected using a plurality of different types of non-destructive inspection means, the non-destructive inspection method of the present embodiment can simply and accurately adjust positions on the object to be inspected identified in detection results of each of the plurality of non-destructive inspection means. It is thereby possible to make multiple-factor based determinations based on detection results by the plurality of different types of non-destructive inspection means.

[0043] In the above embodiment, the respective inspections are performed in order using different non-destructive inspection apparatuses, but even when a plurality of non-destructive inspection means detect the object to be inspected simultaneously or an identical composite apparatus provided with those means performs detections without moving the object to be inspected, it is possible to compare the detection results using marks included in the detection results as positional references. Therefore, even when the identical composite apparatus provided with the plurality of non-destructive inspection means is configured, it is possible to save time and trouble for calibrating coordinates of each non-destructive inspection means. Therefore, the present invention is not limited to a case where a plurality of different types of non-destructive inspection means are configured as separate apparatuses or a case where respective detections are performed in a time sequence.

INDUSTRIAL APPLICABILITY

[0044] The present invention can be used for a non-destructive inspection method for a lithium ion battery or the like.

REFERENCE SIGNS LIST

[0045] 1 object to be inspected [0046] e1, e2, e3 peculiar part [0047] f1, f2 peculiar part [0048] m1, m2, m3 mark