Electronic component

Abstract

To provide an electronic component capable of accurately performing quality determination based on a pinhole formation state.SOLUTION: An electronic component 1 includes: a ceramic body 2 having main surfaces 2a, 2a; electrode units 3, 3 provided on the main surfaces 2a, 2a, respectively; lead terminals 4, 4 electrically connected to the electrode units 3, 3, respectively; and exterior resin 5 provided so as to cover the ceramic body 2, the electrode units 3, 3, and base end portions of the lead terminals 4, 4. The exterior resin 5 has a two-layer structure by an inner layer 11 and an outer layer 12 that differ in color from each other. Color of the inner layer 11 is within 150 color differences from spacing color having the most color difference relative to color of the outer layer 12 in a L*a*b*color space S that takes values from 0 to 255.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to electronic components such as capacitors. [Background technology]

[0002] An example of a conventional electronic component is a ceramic electronic component described in Patent Document 1. This conventional electronic component is configured to include a ceramic body, external electrodes provided on the ceramic body, lead terminals connected to the external electrodes, and an exterior resin that covers the ceramic body and the external electrodes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-274037 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the manufacturing process of electronic components such as those described above, fine holes (hereafter referred to as "pinholes") may form in the exterior resin. The mechanism of pinhole formation is largely unknown, and it is currently difficult to prevent pinhole formation itself. For this reason, manufactured electronic components are subjected to visual inspection, and they are judged as pass / fail based on the state of pinhole formation in the exterior resin. In visual inspection, for example, a component with no visible pinholes is judged as a pass / fail product, and a component with a visible pinhole depth is judged as a pass / fail product within limits, but a component with no visible pinhole depth is judged as a fail product from the perspective of ensuring the reliability of electronic components.

[0005] For example, AI image inspection using a good product model is used for the visual inspection of electronic components. In this method, for example, by learning only good product data, a good product model with an optimized threshold for good products is generated and used to judge the quality of the visual inspection. However, since this method uses the sum of the color difference between the input image and the output image as the degree of anomaly, it tends to be difficult to obtain sufficient accuracy for anomalies with small area or anomalies with small color difference from the good product image. Since pinholes in electronic components fall into both the above-mentioned categories of anomalies with small area and anomalies with small color difference from the good product image, technology that can improve inspection accuracy is desired.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an electronic component that allows for accurate pass / fail determination based on the state of pinhole formation. [Means for solving the problem]

[0007] The gist of the present disclosure is as follows. [1] A ceramic body having a pair of electrode parts on each of a pair of main surfaces, a pair of electrode parts provided on each of the pair of main surfaces, a pair of lead terminals electrically connected to each of the pair of electrode parts, and an exterior resin provided to cover the ceramic body, the pair of electrode parts, and base end portions of the pair of lead terminals, wherein the exterior resin has a two-layer structure made of an inner layer and an outer layer having different colors, and the color of the inner layer is an L having a value of 0 to 255. * a * b * An electronic component, the color of which has a color difference of 150 or less from a separate color having the largest color difference from the color of the outer layer in a color space.

[0008] In this electronic component, the exterior resin is composed of an inner layer and an outer layer, and the L * a * b *The color of the inner layer is defined based on the color of the outer layer that is the furthest away in color space. In this electronic component, there is a sufficient color difference between the outer layer and the inner layer, so the pinhole formation state can be confirmed by counting the colors that are farthest away from the color of the outer layer in image processing. In this case, if the color difference of the color of the inner layer from the color of the furthest away is within 150, it is possible to bring the AUC, an evaluation index for binary classification, closer to 1. Therefore, in this electronic component, it is possible to accurately judge the pass / fail state based on the pinhole formation state.

[0009] [2] The electronic component according to claim 1, wherein the color of the inner layer has a color difference from the separated color within 100. In this case, it is possible to more reliably bring the AUC, which is an evaluation index for binary classification, closer to 1. This makes it possible to more accurately determine pass / fail based on the state of pinhole formation.

[0010] [3] The color of the outer layer is * a * b * The electronic component according to claim 1, wherein the color difference from the vertex color at the vertex of the color space is within 50. In this case, the color difference between the color of the outer layer and the color of the spacer can be sufficiently ensured, and as a result, the color difference between the outer layer and the inner layer can be easily ensured. Therefore, the accuracy of the pass / fail judgment based on the state of pinhole formation can be further improved. In addition, the freedom of selection of the resin material used for the inner layer can be ensured.

[0011] [4] The color of the outer layer is the L * a * b * The electronic component according to claim 1, wherein the color difference from the edge color located at the edge of the color space is within 50. In this case, the color difference between the color of the outer layer and the color of the space can be sufficiently ensured, and as a result, the color difference between the outer layer and the inner layer can be easily ensured. Therefore, the accuracy of the pass / fail judgment based on the state of pinhole formation can be further improved. In addition, the freedom of selection of the resin material used for the inner layer can be ensured.

[0012] [5] The electronic component according to any one of claims 1 to 4, wherein the thickness of the inner layer is greater than the thickness of the outer layer at least in a portion of the exterior resin closer to the pair of lead terminals than the ceramic body. In the exterior resin, pinholes tend to occur more easily in a portion closer to the pair of lead terminals than the ceramic body. By making the thickness of the inner layer in this portion greater than the thickness of the outer layer, the inner layer is more likely to be exposed from the outer layer in a pinhole deep enough to reach the lead terminals, thereby ensuring the accuracy of pass / fail judgment.

[0013] [6] The electronic component according to any one of claims 1 to 4, wherein the thickness of the outer layer is greater than the thickness of the inner layer at least in a portion of the exterior resin closer to the pair of lead terminals than the ceramic body. In the exterior resin, pinholes tend to occur more easily in a portion closer to the pair of lead terminals than the ceramic body. By making the thickness of the outer layer in this portion greater than the thickness of the inner layer, the inner layer is less likely to be exposed from the outer layer in the case of pinholes that are too deep to reach the lead terminals or the ceramic body, and this makes it possible to prevent a product that is within the limit from being determined to be defective. Effect of the Invention

[0014] According to the present disclosure, it is possible to accurately determine pass / fail based on the state of pinhole formation. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view of an electronic component according to an embodiment of the present disclosure viewed from the front. [Diagram 2] 2 is a schematic cross-sectional view of the electronic component shown in FIG. 1 as viewed from the side. [Diagram 3] FIG. 1 is a diagram showing the relationship between the color of an outer layer and the color of an inner layer in the L*a*b* color space. [Figure 4] 3 is a flowchart showing an example of a visual inspection of the electronic component shown in FIGS. 1 and 2. [Diagram 5] 13(a) and (b) are diagrams showing the relationship between the ROC curve and the AUC. [Figure 6] 13(a) and (b) are diagrams showing the relationship between the ROC curve and the AUC. [Figure 7] 13(a) and (b) are diagrams showing the relationship between the ROC curve and the AUC. [Figure 8] 6(a) and 6(b) are diagrams showing the evaluation results of AUC in the visual inspection of the electronic component according to the first embodiment. [Figure 9] 13(a) and 13(b) are diagrams showing evaluation results of AUC in visual inspection of an electronic component according to Example 2. [Figure 10] 13(a) and 13(b) are schematic enlarged cross-sectional views showing a main part of an electronic component according to a modified example. [Figure 11] 13(a) and 13(b) are schematic enlarged cross-sectional views showing a main part of an electronic component according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, preferred embodiments of an electronic component according to one aspect of the present disclosure will be described in detail with reference to the drawings.

[0017] FIG. 1 is a schematic cross-sectional view of an electronic component according to an embodiment of the present disclosure, as viewed from the front. FIG. 2 is a schematic cross-sectional view of the electronic component shown in FIG. 1, as viewed from the side. The electronic component 1 shown in FIGS. 1 and 2 is configured as a radial lead type single plate capacitor. The electronic component 1 is mounted on a substrate of an electronic device using a bonding material such as solder. The electronic component 1 includes a ceramic body 2, a pair of electrodes 3, 3, a pair of lead terminals 4, 4, and an exterior resin 5. Of a disk-shaped portion 5A of the exterior resin 5 described below, a surface in a direction in which the lead terminals 4 extend is a mounting surface R when the electronic component is mounted on a substrate.

[0018] For convenience of explanation, in the following description, the mounting surface R is referred to as the bottom, and the surface opposite the mounting surface R is referred to as the top. The normal direction of the mounting surface R is referred to as the height direction, the opposing direction of the main surfaces 2a, 2a of the ceramic body 2 is referred to as the thickness direction, and the direction perpendicular to the normal direction of the mounting surface R and the opposing direction of the main surfaces 2a, 2a is referred to as the width direction. The electronic component 1 is configured to be symmetrical when viewed from each of the normal direction of the mounting surface R, the thickness direction, and the width direction.

[0019] The ceramic body 2 is, for example, a dielectric element. The dielectric element is made of, for example, a dielectric material (BaTiO 3 System: Ba(Ti,Zr)O 3 system, or (Ba,Ca)TiO 3 The ceramic green sheet is made of a sintered body containing dielectric ceramics such as SiO2-based ceramics.

[0020] The overall shape of the ceramic body 2 is a disk or a flattened cylinder. The ceramic body 2 has a pair of circular main surfaces 2a, 2a facing each other, and a peripheral surface 2b connecting the main surfaces 2a, 2a. The ceramic body 2 is disposed such that the facing direction of the main surfaces 2a, 2a intersects (is perpendicular to) the normal direction of the mounting surface R.

[0021] The electrode parts 3, 3 are provided on each of the main surfaces 2a, 2a. The electrode parts 3 are provided, for example, so as to cover the entire main surface 2a. One of the electrode parts 3 is a positive electrode, and the other is a negative electrode. The electrode parts 3 are formed by a sintered layer of an electrode paste containing metal and glass. For example, Cu, Ni, Ag, etc. can be used as the metal.

[0022] The lead terminals 4, 4 are electrically connected to the electrode portions 3, 3, respectively. The lead terminal 4 connected to the + electrode is a + terminal, and the lead terminal 4 connected to the - electrode is a - terminal. A bonding material such as solder can be used to connect the lead terminals 4 to the electrode portions 3. Examples of materials constituting the lead terminals 4 include phosphor bronze, stainless steel, and Ni-Fe alloys (e.g., 42 alloy). A metal plating layer such as a Ni plating layer or a Sn plating layer may be provided on the surface of the lead terminal 4. The plating layer may be either a single layer or a multilayer.

[0023] The lead terminal 4 has a connection portion 4A connected to the electrode portion 3 on the main surface 2a of the ceramic body 2, and a hanging portion 4B that protrudes continuously from the connection portion 4A toward the mounting surface R. As shown in FIG. 1, the connection portion 4A of one lead terminal 4 extends in the in-plane direction of the electrode portion 3 from near the center of the ceramic body 2 toward one outer side in the width direction when viewed from the opposing direction of the main surfaces 2a, 2a. The connection portion 4A of the other lead terminal 4 extends in the in-plane direction of the electrode portion 3 from near the center of the ceramic body 2 toward the other outer side in the width direction when viewed from the opposing direction of the main surfaces 2a, 2a. The hanging portion 4B extends linearly from the tip of the connection portion 4A along the normal direction of the mounting surface R when viewed from the opposing direction of the main surfaces 2a, 2a.

[0024] 2, a kink portion 4C is provided at the middle of hanging portion 4B. Kinking is a bending process performed for the purpose of facilitating temporary fixing of electronic component 1 to a substrate. Due to kink portion 4C, hanging portion 4B is bent toward the center in the thickness direction at a position below ceramic body 2. When electronic component 1 is viewed in the width direction, the positions of hanging portions 4B, 4B on the tip side of kink portion 4C in lead terminals 4, 4 in the thickness direction are aligned with each other.

[0025] The exterior resin 5 is a member that protects main parts such as the ceramic body 2. The exterior resin 5 is provided so as to cover the ceramic body 2 and the base end portions of the lead terminals 4, 4. In this embodiment, the exterior resin 5 covers the base end portions of the lead terminals 4, 4 to include the kink portion 4C. That is, in this embodiment, the kink portion 4C is located between the ceramic body 2 and the mounting surface R in the height direction of the electronic component 1, and is embedded in the exterior resin 5.

[0026] The exterior resin 5 is made of, for example, an insulating resin material. The exterior resin 5 is formed, for example, by a dipping method or injection molding using a mold. The exterior resin 5 has a shape roughly corresponding to the shapes of the ceramic body 2, the electrode portions 3, 3, and the lead terminals 4, 4. The exterior resin 5 has a disk-shaped portion 5A that covers the ceramic body 2 and the electrode portions 3, 3, and a pair of protruding portions 5B, 5B that protrude below the disk-shaped portion 5A and cover the base end portions of the lead terminals 4, 4.

[0027] The exterior resin 5 has a two-layer structure of an inner layer 11 and an outer layer 12, which are different in color from each other. The inner layer 11 integrally covers the ceramic body 2, the electrode parts 3, 3, and the lead terminals 4, 4. The outer layer 12 is formed so as to cover the entire inner layer 11, and integrally covers the ceramic body 2, the electrode parts 3, 3, and the lead terminals 4, 4 together with the inner layer 11. Examples of the resin material constituting the inner layer 11 include epoxy resin and silica. Examples of the resin material constituting the outer layer 12 include epoxy resin and silica, similar to the inner layer 11. In the example of FIG. 1 and FIG. 2, the thickness of the inner layer 11 and the thickness of the outer layer 12 are uniform and equal to each other regardless of the position.

[0028] The inner layer 11 and the outer layer 12 are different in color from the viewpoint of detecting pinholes P (see FIG. 10(a) and FIG. 11(b)) in the exterior resin 5 with high accuracy by image processing. * a * b * It can be expressed using the color space L * a* b * The color space is L, which indicates lightness. * Axis and a showing chromaticity * axis and b * The L axis represents the complementary color space. * a * b * The color space was standardized by the International Commission on Illumination (CIE) and is adopted in Japan as JIS (JIS Z 8781-4).

[0029] The L shown in Figure 3 * a * b * Color space S is L * , a * , b * Each of these is a three-dimensional orthogonal space that takes values ​​from 0 to 255. * The smaller the value of L, the darker the color. * The smaller the value, the brighter the color. * , b * L * a * b * The closer to the edge of the color space S the more vivid the color becomes, and * , b * L * a * b * The closer the value is to the center of the color space S, the duller the color is. * a * b * The difference (color difference) ΔE between two colors in a color space S is expressed as the distance between two points in the space, as shown in the following formula (1).

number

[0030] In this embodiment, the color of the inner layer 11 is L * a * b * The color difference from the color of the outer layer 12 having the largest color difference in the color space S is within 150, preferably within 100. For example, as shown in FIG. 3, the color of the outer layer 12 is * a * b* When the coordinates are [200, 117, 115], the L of the point Kr that shows the color with the largest color difference from the color of the outer layer 12 * a * b * The coordinates are [0, 255, 255] (the color difference between points Kg and Kr is estimated to be about 280 from formula (1)). In this case, the color of the inner layer 11 is selected from colors located in region R1 whose color difference from point Kr, which indicates the separated color, is within 150, preferably within 100.

[0031] In selecting the color of the inner layer 11, the color of the outer layer 12 is * a * b * The color may be selected from colors whose color difference from the color (vertex color) located at the vertex Kp of the color space S is within 50. In addition, the color of the outer layer 12 may be selected from colors whose color difference from the vertex color is within 50. * a * b * The color may be selected from colors whose color difference from the color (side color) located on the side Kh of the color space S is within 50. In this embodiment, the color of the outer layer 12 is selected from colors located in the region R2 whose color difference from the vertex color is within 50 or whose color difference from the side color is within 50.

[0032] Fig. 4 is a flow chart showing an example of visual inspection of an electronic component. As shown in Fig. 4, when visual inspection of an electronic component 1 is performed, first, a detection color range in image processing is set based on the color of the inner layer 11 (step S01). The detection color range is set, for example, to a range that includes the color of the inner layer 11. In this embodiment, the color of the inner layer 11 is set within an area R1 where the color difference from a point Kr indicating a separation color is within 150, preferably within 100, so for example, this area R1 is set as the detection color range.

[0033] After the detection color range is set, an image of the appearance of the electronic component 1 is captured using an imaging device such as a camera (step S02). Here, images of the front and back sides (both sides in the thickness direction) of the electronic component 1 are respectively captured, and image data based on the imaging results is obtained. When performing an appearance inspection on multiple electronic components 1, images may be captured while the multiple electronic components 1 are being transported by a transport means such as a conveyor.

[0034] Next, among the pixels included in the acquired image data of the front and back of the electronic component 1, the number of pixels whose colors are within the detection color range is counted (step S03). In counting the number of pixels, for example, the color of each pixel is calculated by dividing the image data of the front and back of the electronic component 1 by the L, using OpenCV (Open Source Computer Vision Library) of Python. * a * b * The color space is converted into coordinates in the color space, and the total number of pixels of the color within the detection color range in the acquired image data of the front and back of the electronic component 1 is counted.

[0035] Next, it is determined whether the number of pixels of the colors in the detection color range is equal to or less than a threshold value (step S04). As described above, the colors in the detection color range are set to the color of inner layer 11 and its neighboring colors. If no pinhole P is formed in exterior resin 5, only outer layer 12 is exposed on the surface of electronic component 1, and therefore the image data of electronic component 1 does not include pixels of colors in the detection color range. On the other hand, if a pinhole P is formed in exterior resin 5, inner layer 11 is exposed at the position of pinhole P. Therefore, it is possible to determine whether or not a pinhole P is formed in exterior resin 5 based on the number of pixels of the colors in the detection color range.

[0036] In step S04, if the number of pixels of the color in the detection color range is equal to or less than the threshold, the electronic component 1 is determined to be a pass (step S05). If the number of pixels of the color in the detection color range exceeds the threshold, the electronic component 1 is determined to be a defective product (step S06). In step S05, a further threshold may be set to determine whether the product is a pass or a pass-within-limit product. In this case, for example, a determination can be made such that if the number of pixels of the color in the detection color range is 0, the product is a pass within limit product if it is 1 to 4, and the product is a defective product if it is 5 or more.

[0037] The appearance inspection shown in FIG. 4 may be combined with AI image inspection using a good product model. In AI image inspection, for example, a good product model with an optimized threshold for good products is generated by learning only good product data, and the total color difference between the input image and the output image is used as the degree of abnormality to determine whether the product is good or bad. When combining the appearance inspection shown in FIG. 4 with AI image inspection, the AI ​​image inspection may be performed first, and the appearance inspection shown in FIG. 4 may be performed on electronic components 1 that have been determined to be good. Conversely, the appearance inspection shown in FIG. 4 may be performed first, and the AI ​​image inspection may be performed on electronic components 1 that have been determined to be good.

[0038] Next, an evaluation test of the determination ability when the visual inspection shown in FIG. 4 is performed on the electronic component 1 will be described.

[0039] In this evaluation test, 20 images of non-defective products were prepared for the electronic components of Examples 1 and 2, 10 of which were used as-is images of non-defective products, and the remaining 10 were used as-is images of non-defective products. * a * b * The image of the defective product was superimposed with a dummy pinhole image of the color with coordinates [0,255,255] (corresponding to the above-mentioned distant color).The color [0,255,255] was then used as the standard, and the number of pixels whose color difference from the standard color was below a threshold was used to calculate the degree of abnormality, and the AUC (Area Under ROC Curve) was calculated.

[0040] AUC is an evaluation index for binary classification such as pass / fail judgment, and has a value ranging from 0 to 1. If pass / fail classification is possible perfectly, the AUC value is 1, and if pass / fail classification is random, the AUC value is 0.5. AUC is a value determined based on the ROC (Receiver Operating Characteristics) curve, and is specifically expressed as the area below the ROC curve.

[0041] The ROC curve is expressed on a two-dimensional plane with the horizontal axis representing the false positive rate (FPR) and the horizontal axis representing the true positive rate (TPR). The false positive rate is the rate at which products are correctly judged to be good products to the total number of good products. The true positive rate is the rate at which products are erroneously judged to be good products to all defective products. FIG. 5(a) is a diagram showing an example of the distribution of good products and defective products. As shown in FIG. 5(a), the true positive rate and false positive rate change when the threshold for judgment of good or bad products is changed. FIG. 5(b) is a diagram showing the tendency of the ROC curve in general binary classification. The true positive rate and false positive rate at the thresholds A, B, and C shown in FIG. 5(a) correspond to points A, B, and C of the ROC curve shown in FIG. 5(b), for example.

[0042] As shown in FIG. 6(a), when the distributions of good and bad products are completely the same, that is, when the classification of good and bad products is random, the ROC curve is a straight line with a slope of 1 connecting the coordinates [0,0] and [1,1] as shown in FIG. 6(b). In this case, the AUC represented by the area below the ROC curve is 0.5. On the other hand, as shown in FIG. 7(a), when the distributions of good and bad products are completely separate, that is, when the classification of good and bad products can be completely performed, the ROC curve is a straight line connecting the coordinates [0,0] and [0,1], and also connecting the coordinates [0,1] and [1,1] as shown in FIG. 7(b). In this case, the AUC represented by the area below the ROC curve is 1.0.

[0043] 8(a) and 8(b) are diagrams showing the evaluation results of AUC in the appearance inspection of the electronic component according to Example 1. As shown in FIG. 8(a), in Example 1, the color coordinates of the outer layer were light blue [200, 117, 115]. The color coordinates of the outer layer were calculated by randomly extracting the color of the outer layer of the sample at five points and averaging the color coordinates at each of the extracted points. In this case, the color coordinates of the intermediate color having the largest color difference from the color of the outer layer are brown [0, 255, 255].

[0044] In Figure 8(a), four inner layer colors are extracted and shown: brown [0,255,255], reddish brown [58,197,197], dark brown [87,168,168], and gray [115,140,140]. The color differences between these inner layer colors and the spaced colors are 0, 100, 150, and 200, respectively. When the color difference is 0, 100, and 150, the AUC value is 1.00, while when the color difference is 200, the AUC value is 0.79.

[0045] Fig. 8(b) is a diagram showing the calculation results of AUC when the color difference between the inner layer color and the separation color is in the range of 0 to 400, including the results of Fig. 8(a). As shown in Fig. 8(b), when the color difference is in the range of 0 to 154, the AUC value is maintained at 1.00, whereas when the color difference exceeds 154, the AUC value drops sharply and varies in the range of about 0.1 to 0.7. From this result, it can be confirmed that by keeping the color difference between the inner layer color and the separation color within 150, preferably within 100, the AUC value in the appearance inspection becomes 1.00, and pass / fail judgment based on the formation state of pinholes can be performed with high accuracy.

[0046] 9(a) and 9(b) are diagrams showing the evaluation results of AUC in the appearance inspection of the electronic component according to Example 2. As shown in FIG. 9(a), in Example 1, the color coordinates of the outer layer were dark blue [92, 167, 52]. As in Example 1, the color coordinates of the outer layer were calculated by randomly extracting the color of the outer layer of the sample at five points and averaging the color coordinates at each of the extracted points. In this case, the color coordinates of the intermediate color having the largest color difference from the color of the outer layer are bright green [255, 0, 255].

[0047] In Figure 9(a), four inner layer colors are extracted and shown: bright green [255,0,255], green [197,58,197], dark green [168,87,168], and gray [140,115,140]. The color differences between these inner layer colors and the spacer colors are 0,100,150,200, respectively. When the color difference is 0,100,150, the AUC value is 1.00, whereas when the color difference is 200, the AUC value is 0.31.

[0048] Figure 9(b) is a diagram showing the calculation results of the AUC in the range where the color difference between the color of the inner layer and the separated color is 0 or more and 400 or less, including the results of Figure 9(a). As shown in Figure 9(b), in the range where the color difference is 0 or more and 168 or less, the value of the AUC is maintained at 1.00, whereas in the range where the color difference exceeds 168, the value of the AUC rapidly decreases and varies in the range of about 0.1 to 0.8. From this result, as in Example 1, by setting the color difference between the color of the inner layer and the separated color to be within 150, preferably within 100, it can be confirmed that the value of the AUC in the appearance inspection becomes 1.00, and the pass / fail determination based on the formation state of the pinholes can be accurately performed.

[0049] As described above, in the electronic component 1, the exterior resin 5 is composed of the inner layer 11 and the outer layer 12, and L * a * b * The color of the inner layer 11 is defined based on the separated color that is farthest from the color of the outer layer 12 in the color space S. In the electronic component 1, since there is a sufficient color difference between the outer layer 12 and the inner layer 11, the formation state of the pinhole P can be confirmed by counting the colors that are far from the color of the outer layer 12 in the image processing. At this time, by setting the color difference between the color of the inner layer 11 and the separated color to be within 150, it becomes possible to approximate the AUC, which is an evaluation index for binary classification, to 1. Therefore, in the electronic component 1, the pass / fail determination based on the formation state of the pinhole P can be accurately performed.

[0050] In the present embodiment, the color of the inner layer 11 is a color with a color difference of 100 or less from the separated color. In this case, it becomes possible to more reliably approximate the AUC, which is an evaluation index for binary classification, to 1. Therefore, the pass / fail determination based on the formation state of the pinhole P can be performed with higher accuracy.

[0051] In the present embodiment, the color of the outer layer 12 is L * a * b * The present embodiment includes a mode in which the color difference from the vertex color located at the vertex Kp of the color space S is 50 or less. Also, in the present embodiment, the color of the outer layer 12 is L * a * b* This includes an embodiment in which the color difference from the side color located at the side Kh of the color space S is within 50. According to such an embodiment, the color difference between the color of the outer layer 12 and the separation color can be sufficiently ensured, and as a result, it becomes easier to ensure the color difference between the outer layer 12 and the inner layer 11. Therefore, the accuracy of the pass / fail judgment based on the formation state of the pinhole P is further improved. In addition, the freedom of selection of the resin material used for the inner layer 11 can be ensured.

[0052] The present disclosure is not limited to the above-described embodiment. For example, in the above-described embodiment, the thicknesses of the inner layer 11 and the outer layer 12 in the exterior resin 5 are uniform and equal to each other regardless of the location, but as shown in Fig. 10(a), the thickness of the inner layer 11 may be greater than the thickness of the outer layer 12 at least in the portion W of the exterior resin 5 closer to the pair of lead terminals 4, 4 than the ceramic body 2.

[0053] The portion W on the pair of lead terminals 4, 4 side of the ceramic body 2 refers to the region from the lowest point of the circumferential surface 2b of the ceramic body 2 to the tip of the portion covering the base end portions of the lead terminals 4, 4 (see FIGS. 1 and 2). In other words, the portion W includes the portion of the disc-shaped portion 5A of the exterior resin 5 from the lowest point of the circumferential surface 2b of the ceramic body 2 to the mounting surface R, and the pair of protruding portions 5B, 5B.

[0054] In the exterior resin 5, pinholes P tend to occur more easily in a portion W closer to the pair of lead terminals 4, 4 than to the ceramic body 2. By making the thickness of the inner layer 11 in this portion W greater than the thickness of the outer layer 12, as shown in Fig. 10(b), the inner layer 11 is more likely to be exposed from the outer layer 12 in the case of a pinhole P deep enough to reach the lead terminals 4, for example, as shown in Fig. 10(b), thereby ensuring the accuracy of pass / fail judgment. This is also true when a pinhole P deep enough to reach the ceramic body 2 is formed.

[0055] 11(a), for example, the thickness of the outer layer 12 may be greater than the thickness of the inner layer 11 in at least a portion W of the exterior resin 5 that is closer to the pair of lead terminals 4, 4 than the ceramic body 2. In this case, as shown in FIG 11(b), in a pinhole P that is deep enough not to reach the lead terminals 4, 4 or the ceramic body 2, the inner layer 11 is unlikely to be exposed from the outer layer 12, making it possible to prevent a non-defective product from being determined to be defective.

[0056] 10(a) and 11(a), in the exterior resin 5, the thicknesses of the inner layer 11 and the outer layer 12 may have the above relationship only in at least a portion W that is closer to the pair of lead terminals 4, 4 than the ceramic body 2, or the thicknesses of the inner layer 11 and the outer layer 12 may have the above relationship over the entire exterior resin 5 including the portion W. The thicknesses of the inner layer 11 and the outer layer 12 may have the above relationship over the portion W and a part of the portion excluding the portion W. [Explanation of symbols]

[0057] 1...electronic component, 2...ceramic body, 2a...main surface, 3...electrode portion, 4...lead terminal, 5...exterior resin, 11...inner layer, 12...outer layer, S...L * a * b * Color space, Kp...vertex, Kh...side, W...part closer to the lead terminal than the ceramic body.

Claims

1. a ceramic body having a pair of main surfaces; A pair of electrode portions provided on each of the pair of main surfaces; a pair of lead terminals electrically connected to the pair of electrode portions, respectively; an exterior resin provided to cover the ceramic body, the pair of electrodes, and base end portions of the pair of lead terminals, The exterior resin has a two-layer structure including an inner layer and an outer layer having different colors, The colors of the inner layers are L, each of which has a value between 0 and 255. ＊ a ＊ b ＊ An electronic component, the color of which has a color difference of 150 or less from a separate color having the largest color difference from the color of the outer layer in a color space.

2. 2. The electronic component according to claim 1, wherein the color of the inner layer has a color difference of 100 or less from the color of the separation layer.

3. The color of the outer layer is ＊ a ＊ b ＊ 2. The electronic component according to claim 1, wherein the color difference from a vertex color located at a vertex of the color space is within 50.

4. The color of the outer layer is ＊ a ＊ b ＊ 2. The electronic component according to claim 1, wherein the color difference from a side color located on a side of the color space is within 50.

5. 5. The electronic component according to claim 1, wherein the thickness of the inner layer is greater than the thickness of the outer layer in at least a portion of the exterior resin closer to the pair of lead terminals than the ceramic body.

6. 5. The electronic component according to claim 1, wherein the thickness of the outer layer is greater than the thickness of the inner layer in at least a portion of the exterior resin closer to the pair of lead terminals than the ceramic body.

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