JP5110067B2 - Electronic component and electronic device, and mounting structure of electronic component - Google Patents

Description

  The present invention relates to a structure of a terminal electrode included in a surface-mount type electronic component, an electronic device including the electronic component, and a structure for mounting the electronic component on a substrate.

  The electronic device includes a substrate on which electronic components are mounted. In recent years, electronic devices have become smaller and more functional, and electronic components have been downsized and the mounting density when mounting electronic components on a substrate (the number of electronic components mounted per unit area of the substrate). ) Is requested to improve. From the viewpoint of improving the mounting density, there is a tendency to use a terminal electrode provided on the bottom surface of the electronic component and bonded to the electrode of the substrate by soldering. For example, in Patent Document 1, an electrode is provided on the bottom surface of a surface-mounted electronic component package, and the shape of this electrode is a surface-mounted electronic device formed in a convex shape protruding in the direction of a bonding pad surface of a printed wiring board. Parts are disclosed.

JP 2008-130812 A

  When the solder that joins the terminal electrode of the electronic component and the electrode of the board is melted, the solder is caused by the air entrained in the solder paste when the solder paste is printed or the gas evaporated from the flux contained in the solder paste. Voids may occur inside. It is shown that the technique disclosed in Patent Document 1 can suppress the generation of such voids.

  However, with the technique disclosed in Patent Document 1, when the dimensions of the electronic component are reduced, it is difficult to form the terminal electrode of the electronic component in a convex shape, and it is difficult to suppress the generation of voids. The present invention has been made in view of the above, and an object of the present invention is to reduce voids in solder when an electronic component is attached to a substrate.

  In order to solve the above-described problems and achieve the object, an electronic component according to the present invention has at least two terminal electrodes provided on the same surface in an electronic component having terminal electrodes exposed on the outer surface, The dimension in the longitudinal direction of the electronic component is 1005 M or less, the dimension in the short direction of the terminal electrode is 30 μm or more and 120 μm or less, and the ratio of the dimension in the short direction of the terminal electrode to the dimension in the longitudinal direction is 0.324 or more. It is 0.480 or less.

  According to the present invention, the aspect ratio of the terminal electrode (dimension in the transverse direction / dimension in the longitudinal direction) is 0.324 or more in an electronic component having a dimension in the short direction of the terminal electrode of 305 μm or more and 120 μm or less. 0.480 or less. As a result, when melting the solder between the terminal electrode and the substrate electrode, the terminal electrode can be prevented from covering the solder, so that the gas can easily escape from the molten solder. As a result, voids in the solidified solder can be reduced. And since a terminal electrode and a board | substrate electrode are reliably connected mechanically, electrically, and thermally, reliability improves.

  As a desirable mode of the present invention, in the electronic component, the shape of the surface of the electronic component on which the at least two terminal electrodes are provided is a rectangle, and the longitudinal direction of the surface and the longitudinal direction of the terminal electrode are It is preferable that they are parallel. Thereby, the longitudinal direction of the terminal electrode can be formed along the longitudinal direction of the surface of the electronic component, so that the area of the terminal electrode can be ensured while maintaining the aspect ratio in the above-described range.

  In order to solve the above-described problems and achieve the object, an electronic apparatus according to the present invention includes the electronic component. Since this invention is equipped with the electronic component mentioned above, the void in the solder which joins an electronic component to a substrate electrode can be reduced. Thereby, since the terminal electrode and the substrate electrode are securely and mechanically connected, the reliability of the electronic device is improved.

  In order to solve the above-described problems and achieve the object, the electronic component mounting structure according to the present invention has at least two terminal electrodes provided on the same surface and exposed on the outer surface, and has a longitudinal dimension. 1005M or less, the dimension of the terminal electrode in the short direction is 30 μm or more and 120 μm or less, and the ratio of the terminal electrode to the longitudinal direction in the short direction is 0.324 or more and 0.480 or less, At least two substrate electrodes provided on a mounting surface of a substrate on which an electronic component is mounted, and at least one pair of terminal terminals facing each other among the at least two terminal electrodes, Of the two substrate electrodes, the opposite ends of the substrate electrodes respectively corresponding to the pair of opposing terminal electrodes are overlapped.

  The present invention comprises a structure in which at least one pair of opposed terminal electrodes facing each other out of at least two terminal electrodes and a facing end of each substrate electrode corresponding to each of the opposed pair of terminal electrodes are stacked. To do. Thereby, the positioning accuracy of the electronic component with respect to the substrate is improved by aligning the opposing end portions of the terminal electrodes facing the electronic component with the opposing end portions of the substrate electrodes on the corresponding substrate. In addition, the unbalance of the electronic component with respect to the longitudinal central axis and the lateral central axis is reduced, and the electrical characteristics of the electronic component are improved.

  As a desirable mode of the present invention, in the mounting structure of the electronic component, it is preferable that end portions of the pair of terminal electrodes facing each other are end portions parallel to the longitudinal direction of the electrodes. As a result, it is possible to more effectively create an action of superposing the long side end of the terminal electrode on the long side end of the substrate electrode, so that the electronic component is moved to a predetermined position of the substrate electrode on the substrate. The automatic positioning function can be exhibited effectively.

  The present invention can reduce voids in solder when an electronic component is attached to a substrate.

FIG. 1 is a schematic diagram illustrating a state in which the electronic component according to Embodiment 1 is mounted on a substrate. FIG. 2 is a perspective view illustrating a part of a process of mounting the electronic component according to the first embodiment on a substrate. FIG. 3 is a schematic diagram of a phenomenon that occurs during reflow. FIG. 4A is a diagram illustrating a relationship between a terminal electrode and a substrate electrode in a conventional electronic component. FIG. 4-2 is a schematic diagram illustrating a state of solder when reflowing a conventional electronic component. FIG. 5A is a diagram illustrating a relationship between terminal electrodes and substrate electrodes in the electronic component of the first embodiment. FIG. 5-2 is a schematic diagram illustrating a state of solder when the electronic component of Embodiment 1 is reflowed. FIG. 5C is a schematic diagram illustrating a state in which a terminal electrode having a protrusion at an end is joined to a substrate electrode by soldering. FIG. 6 is a bottom view of the electronic component according to the first embodiment. FIG. 7-1 is a schematic diagram illustrating a bonding strength test method. FIG. 7B is an explanatory diagram of a method for obtaining the void occurrence rate. FIG. 8 is a bottom view showing an arrangement example of terminal electrodes. FIG. 9A is a bottom view illustrating an arrangement example of terminal electrodes. FIG. 9-2 is a bottom view illustrating an arrangement example of the terminal electrodes. FIG. 10 is a schematic diagram illustrating a mounting structure of an electronic component according to the second embodiment. FIG. 11 is a view as seen from the direction of the arrow X in FIG. FIG. 12 is a schematic diagram illustrating a mounting structure according to another example of the second embodiment. FIG. 13 is a schematic diagram illustrating a mounting structure according to a modification of the second embodiment. FIG. 14 is a plan view showing the relationship between the terminal electrode and the substrate electrode.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a state in which the electronic component according to Embodiment 1 is mounted on a substrate. FIG. 2 is a perspective view showing a part of the process of mounting the electronic component according to the present embodiment on the substrate. FIG. 3 is a schematic diagram of a phenomenon that occurs during reflow. As shown in FIG. 1, the electronic component 1 has a rectangular parallelepiped shape having a plurality of surfaces in plan view, and the terminal electrodes 2 provided on the bottom surface 1 </ b> B are exposed to the outside from the outer surface of the electronic component 1. . In the electronic component 1, the terminal electrode 2 is mechanically and electrically connected to a terminal electrode 4 (hereinafter referred to as a substrate electrode) 4 provided on the surface 3 </ b> P of the substrate 3 through solder 5. The terminal electrode 2 is provided only on the bottom surface 1B and does not extend over the side surface of the electronic component 1 connected to the bottom surface 1B. Thus, the electronic component 1 is a so-called surface-mount type electronic component that is joined to the substrate electrode 4 by the terminal electrode 2 provided only on the bottom surface 1B.

  For surface mount type electronic components, in order to reduce mounting voids and voids existing in the solder, it has been used that the terminal electrode of the electronic component is formed from the bottom to the side. Yes. However, along with the downsizing of electronic components, it has become difficult to form terminal electrodes over side surfaces, and the above-described surface-mount type electronic components have come to be used.

  When mounting the electronic component 1 on the substrate 3, first, a solder paste is printed on the substrate electrode 4. At this time, air may be caught in the solder paste. After the solder paste is printed, the electronic component 1 is transported to the position of the substrate electrode 4 by a mounting device (mounter), and placed on the substrate electrode 4 to which the solder paste 5P is applied, as shown in FIG. Thereafter, by heating the solder paste 5P in the reflow process, the solder component of the solder paste 5P is melted, and the terminal electrode 2 of the electronic component 1 and the substrate electrode 4 of the substrate 3 are joined.

When melting of the solder starts in the reflow process, as shown in FIG. 3, the solvent in the flux Fl contained in the solder paste 5P is gasified, or a reducing gas is generated from the solder paste 5P (H ₂ O, HSnBr). ₂ etc.). Moreover, since the intermetallic compound is produced | generated by the metal melting in solder | pewter progressing, the fluidity | liquidity of the solder paste 5P falls. As a result, generated gas such as air, reducing gas, gasified flux Fl and the like entrained in the solder paste 5P is easily confined in the solder paste 5P.

  FIG. 4A is a diagram illustrating a relationship between a terminal electrode and a substrate electrode in a conventional electronic component. FIG. 4-2 is a schematic diagram illustrating a state of solder when reflowing a conventional electronic component. FIG. 5A is a diagram illustrating a relationship between the terminal electrode and the substrate electrode in the electronic component of the present embodiment. FIG. 5B is a schematic diagram illustrating the state of the solder when the electronic component of the present embodiment is reflowed. FIG. 5C is a schematic diagram illustrating a state in which a terminal electrode having a protrusion at an end is joined to a substrate electrode by soldering.

  As shown in FIG. 3, the solder paste 5 </ b> P is in a state where it is covered with the terminal electrode 2. In the conventional electronic component shown in FIG. 4-1, when the area of the terminal electrode 102 is made large enough to ensure the bonding strength between the terminal electrode 102 and the substrate electrode 104, in the reflow process, FIG. As shown, the terminal electrode 102 functions to cover the melted solder 105. Due to this function, the gas G such as generated gas or air is difficult to escape upward from the molten solder 105. As a result, the gas G remains in the solder 105 and voids are formed in the solder 105 after the solder 105 is solidified. Here, in the structure in which the terminal electrode of the electronic component is formed so as to extend from the bottom surface to the side surface, in the reflow process, since the solder wets to the side surface along the terminal electrode, the gas easily escapes from the molten solder. Therefore, there were few voids formed in the solder.

  Therefore, in the present embodiment, as shown in FIG. 5A, the shape of the terminal electrode 2 is maintained while maintaining the area of the terminal electrode 2 at a size that can secure the bonding strength between the terminal electrode 2 and the substrate electrode 4. change. Specifically, by reducing one side of the terminal electrode 2 having a rectangular shape, the function of the terminal electrode 2 as a lid for the molten solder 5 is suppressed, and the gas G in the molten solder 5 escapes to the outside. Make it easier. As a result, it has been found that voids formed in the solder 5 that joins the terminal electrode 2 and the substrate electrode 4 can be reduced. As a result, a decrease in bonding strength between the terminal electrode 2 and the substrate electrode 4 is suppressed, and the two are electrically connected reliably. Furthermore, since the heat of the electronic component 1 is easily transferred from the terminal electrode 2 to the substrate electrode 4 through the solder 5, the heat dissipation performance of the electronic component 1 is improved. In addition, long-term reliability of bonding between the terminal electrode 2 and the substrate electrode 4 can be ensured.

  Further, as shown in FIG. 5C, the terminal electrode 2 may have a protrusion 6 formed on the edge of the joint surface for manufacturing reasons. Since the protruding portion 6 faces the substrate electrode 4, when the terminal electrode 2 is joined to the substrate electrode 4 with the solder 5, the protruding portion 6 protrudes toward the solder 5. In the conventional structure shown in FIG. 4A, the protrusions 6 make it difficult for gas to escape from the molten solder, and voids are more easily formed. However, in this embodiment, since one side of the terminal electrode 2 is made small while the area of the terminal electrode 2 is maintained at a size that can secure the bonding strength between the terminal electrode 2 and the substrate electrode 4, Even if it is formed, the gas can easily escape from the molten solder. As a result, formation of voids can be suppressed.

  Further, since the protruding portion 6 has an effect of increasing the contact area between the terminal electrode 2 and the solder 5, the terminal electrode 2 is protruded from the viewpoint of bonding strength, electrical characteristics, etc. between the terminal electrode 2 and the substrate electrode 4. It is preferable to have the part 6. Since the electronic component 1 can suppress the formation of voids in the solder 5 even if the protrusion 6 is formed on the terminal electrode 2, the terminal electrode 2 and the substrate electrode 4 can be reliably bonded. As a result, the electronic component 1 is further improved in bonding strength, electrical characteristics, and the like. Next, the electronic component 1 will be described in more detail.

  FIG. 6 is a bottom view of the electronic component according to the present embodiment. FIG. 7-1 is a schematic diagram illustrating a bonding strength test method. FIG. 7B is an explanatory diagram of a method for obtaining the void occurrence rate. In this embodiment, after ensuring the bonding strength between the terminal electrode 2 and the substrate electrode 4, the shape of the terminal electrode 2 is rectangular (rectangular). The bonding strength varies depending on the size of the electronic component 1. Normally, the larger the size of the electronic component 1, the greater the required bonding strength. The bonding strength increases as the bonding area between the terminal electrode 2 and the substrate electrode 4 increases. In this embodiment, since the area of the terminal electrode 2 is smaller than the area of the substrate electrode 4, the junction area is defined by the terminal electrode 2.

  As shown in FIG. 6, the terminal electrode 2 has a rectangular shape in plan view, the dimension in the longitudinal direction (hereinafter referred to as the long side length) is w, and the dimension in the short direction (hereinafter referred to as the short side length). Is h). Here, the ratio of the short side length h to the long side length w is defined as an aspect ratio h / w. The relationship between the aspect ratio h / w and bonding strength, and the aspect ratio h / w and void generation rate were investigated. The bonding strength is determined when the electronic component 1 is detached from the substrate 3 by applying a force F in a direction parallel to the plate surface of the substrate 3 to the electronic component 1 bonded on the substrate 3 as shown in FIG. Was evaluated by the force F (N) of the product (evaluation based on the share strength).

  The void generation rate is the volume of voids in the entire volume of solder existing between one terminal electrode 2 of the electronic component 1 and the substrate electrode 4. However, it is difficult to determine the void volume. Therefore, as shown in FIG. 7-2, the void generation rate is the total area of voids existing in the terminal electrode 2 when one terminal electrode 2 of the electronic component 1 is observed from a direction perpendicular to the terminal surface. A ratio ΣAv / As of ΣAv to the area As = h × w of the terminal electrode 2 is regarded as a void generation rate. Here, Av is the area of the void V shown in FIG. The area Av of the void V is obtained from, for example, a processed image obtained by performing image processing (for example, binarization processing) on an image obtained by capturing the terminal electrode 2 after bonding using X-rays.

  Table 1 shows the evaluation results of the bonding strength and the void generation rate with respect to the aspect ratio h / w. The joint strength was evaluated based on the decrease rate of the joint strength after the reliability test was performed with respect to the joint strength before the reliability test for applying the thermal cycle load and the shear load. When the rate of decrease in bonding strength was the same as that of the conventional product, it was evaluated as ◯, and when it was lower than that of the conventional product, it was rated as x. The void generation rate is a relative evaluation of the void generation rate obtained by the above-described method. The void generation rate is lower than that of the conventional product. As for the void occurrence rate, ○ or ◎ is acceptable, and Δ or × is unacceptable. From the results of Table 1, it can be seen that if the aspect ratio h / w is smaller than the predetermined lower limit, the required bonding strength cannot be obtained as a result of the inability to secure the bonding area. On the other hand, when the aspect ratio h / w is larger than a predetermined upper limit value, it can be seen that a void suppressing effect cannot be obtained.

  From the above results, the aspect ratio h / w is preferably from 0.324 to 0.480, and more preferably from 0.324 to 0.375. Within these ranges, the bonding strength between the terminal electrode 2 and the substrate electrode 4 can be ensured while suppressing the generation of voids in the solder 5 that bonds the two between the terminal electrode 2 and the substrate electrode 4. On the other hand, if the length h of the short side of the terminal electrode 2 exceeds 120 μm, the absolute bonding area between the terminal electrode 2 and the substrate electrode 4 increases even if the aspect ratio h / w is in the above range. The effect of suppressing the generation of voids is reduced. In addition, when the short side length h of the terminal electrode 2 is less than 30 μm, the absolute bonding area between the terminal electrode 2 and the substrate electrode 4 is reduced even if the aspect ratio h / w is in the above range. Necessary joint strength cannot be secured. Therefore, in the present embodiment, the above-described range of the aspect ratio h / w is suitable when the short side length h of the terminal electrode 2 is 30 μm or more and 120 μm or less.

  The dimension of the terminal electrode 2 of the electronic component 1 is related to the dimension of the electronic component 1. As shown in FIG. 6, the electronic component 1 has a rectangular shape in plan view (the shape of the bottom surface 1 </ b> B is rectangular), a longitudinal direction (a direction indicated by an arrow L in FIG. 6, the same applies hereinafter) and a short direction (see FIG. 6). 6, the direction indicated by the arrow S, and so on). The electronic component 1 including the terminal electrode 2 having a short side length h of 30 μm or more and 120 μm or less has a dimension of 1005 M or less. Here, 1005M is a dimension notation to be described later. The dimension W in the longitudinal direction of the electronic component 1 shown in FIG. 6 is 1.0 ± 0.05 mm, and the dimension H in the lateral direction is 0.5 ± 0.05 mm. It means that. Therefore, the electronic component 1 having a dimension of 1005M or less has a dimension W in the longitudinal direction shown in FIG. 6 of 1.05 mm or less and a dimension H in the lateral direction of 0.55 mm or less. The electronic component 1 of the present embodiment is rectangular in plan view and is suitable for such dimensions. In addition, the notation of 1005M is a dimension symbol prescribed | regulated to C5101-21: 2006 (IEC60384-21: 2004).

  When the short side length h of the terminal electrode 2 is about 30 μm, the electronic component 1 having such a terminal electrode 2 has a dimension W in the longitudinal direction of 0.2 mm ± α and a dimension H in the short direction of 0. 1 mm ± β. Here, α and β are dimensional tolerances. Thus, in the electronic component 1 of the present embodiment, the dimension W in the longitudinal direction is 0.2 mm ± α, the dimension H in the lateral direction is 0.1 mm ± β, and the dimension W in the longitudinal direction is 1.0 mm ± 0. .05 mm or less, and suitable for the dimension H in the width direction of 0.5 ± 0.05 mm or less.

  8, 9-1, and 9-2 are bottom views showing examples of arrangement of terminal electrodes. As for the terminal electrode 2 of the electronic component 1 shown in FIG. 8, the long side length w is larger than the short side length h. The electronic component 1 is arranged such that the longitudinal direction of the bottom surface 1B and the short direction of the terminal electrode 2 are parallel to each other. FIG. 9A shows a case where the electronic component 1 includes two terminal electrodes 2. The longitudinal direction of the bottom surface 1B of the electronic component 1 and the short direction of the terminal electrode 2 are parallel, and the terminal electrode It arrange | positions so that the edge parts in the longitudinal direction of 2 may oppose. If the aspect ratio h / w of the terminal electrode 2 is within the above range, the terminal electrode 2 may be arranged as shown in FIGS. 9-1 and 9-2.

  Here, when there are two terminal electrodes 2, the longitudinal direction of the bottom surface 1 </ b> B of the electronic component 1 and the longitudinal direction of the terminal electrode 2 are parallel to each other, and the end portions in the short direction of the terminal electrode 2 face each other. It may be configured. However, in this arrangement, depending on the size of the electronic component 1 in the longitudinal direction, the pair of terminal electrodes 2 cannot be arranged in the bottom surface 1B of the electronic component 1 while the aspect ratio h / w of the terminal electrode 2 is in the above-described range. Sometimes.

  Here, if the terminal electrode 2 is arranged as shown in FIG. 9-1, the short direction of the terminal electrode 2 is parallel to the long side direction of the bottom surface 1 </ b> B of the electronic component 1. Compared with the case where it is parallel to the longitudinal direction of the bottom surface 1B, the long side length w of the terminal electrode 2 can be ensured while ensuring the necessary interval t between the terminal electrodes 2. As a result, according to this configuration, the pair of terminal electrodes 2 can be easily placed in the bottom surface 1B of the electronic component 1 while keeping the aspect ratio h / w of the terminal electrodes 2 in the above-described range. In the terminal electrode 2 shown in FIG. 9A, the long side length w is larger than the short side length h.

  Further, as shown in FIG. 9B, when there are two terminal electrodes 2 having a long side length w larger than the short side length h, the longitudinal direction of the bottom surface 1B of the electronic component 1 and the terminal electrode 2 The longitudinal direction of the terminal electrode 2 may be parallel to each other, and the end portions in the longitudinal direction of the terminal electrode 2 may be opposed to each other. In this way, since the terminal electrode 2 can be formed over the entire longitudinal direction of the bottom surface 1B of the electronic component 1, the aspect ratio h / w of the terminal electrode 2 is in the above-described range, and the pair of terminal electrodes 2 It becomes easy to secure the interval t between each other. As a result, the electronic component 1 can be easily placed in the bottom surface 1B.

  In general, the electronic component 1 having two terminal electrodes 2 often has a small size in the longitudinal direction and the short direction, and the interval between the substrate electrodes 4 corresponding to the terminal electrodes 2 arranged to face each other is also small. Many. When the distance between the substrate electrodes 4 is reduced, it becomes difficult to reliably apply the solder paste onto the substrate electrodes 4. However, if the terminal electrode 2 is arranged as shown in FIGS. 9-1 and 9-2, it is easy to secure the interval t between the substrate electrodes 4 corresponding to the terminal electrodes 2 arranged to face each other. It becomes easy to reliably apply the solder paste on the electrode 4. As a result, even if the dimensions of the electronic component 1 are small, the terminal electrode 2 and the substrate electrode 4 can be more reliably joined.

  Here, the terminal electrode 2 shown in FIG. 6 is arranged so that the longitudinal direction of the bottom surface 1B of the electronic component 1 and the longitudinal direction of the terminal electrode 2 are parallel to each other. With this configuration, the distance t between adjacent terminal electrodes 2 in the short direction of the bottom surface 1B of the electronic component 1 is set so that the longitudinal direction of the bottom surface 1B of the electronic component 1 and the short direction of the terminal electrode 2 are parallel. It can take large compared with the structure (refer FIG. 8) arrange | positioned. As a result, it is not necessary to make the above-mentioned interval t darkly small, and it becomes easy to reliably apply the solder paste onto the substrate electrode 4. As a result, the terminal electrode 2 and the substrate electrode 4 can be more reliably joined. Further, according to the arrangement of the terminal electrode 2 shown in FIG. 6, the longitudinal direction of the terminal electrode 2 is parallel to the longitudinal direction of the bottom surface 1 </ b> B having a sufficient size. It becomes easy to secure. As a result, it becomes easier to secure a bonding area in a state where the aspect ratio h / w of the terminal electrode 2 is in the above-described range.

  In some cases, only the terminal electrode 2 shown in FIG. Even in this case, if the aspect ratio h / w of the terminal electrode 2 is set within the above range, an effect of reducing voids in the solder can be obtained. As described above, the electronic component 1 can reduce voids in the solder regardless of the arrangement of the terminal electrode 2 if the aspect ratio h / w of the terminal electrode 2 is within the above-described range. Therefore, since the arrangement of the terminal electrode 2 according to the specifications of the board 3 or the electronic device on which the electronic component 1 is mounted can be adopted, there is an advantage that the degree of freedom in designing the board 3 and the electronic equipment is improved.

  The electronic component 1 of this embodiment is, for example, a chip capacitor, a chip inductor, a balun, a coupler, a filter, a varistor, a multilayer chip component, or the like. In addition, the electronic component 1 can be applied as an electronic component provided in an electronic device such as a PDA (Personal Data Assistance) such as a mobile phone, a personal computer, a television, and a game machine. In particular, since the electronic component 1 can reduce the voids present in the solder 5 between the terminal electrode 2 and the substrate electrode 4 to ensure the bonding strength, the electronic component 1 is assumed to be subjected to an impact or the like. Preferred for equipment. Examples of such electronic devices include electronic devices that are expected to be carried and used, such as mobile phones and PDAs.

  As described above, in the present embodiment, in a surface-mount type electronic component of 1005 M or less, the aspect ratio of the terminal electrode is set to 0.324 or more and 0.480 or less, preferably 0.324 or more and 0.375 or less. As a result, when the solder paste between the terminal electrode and the substrate electrode is heated to melt the solder, the function as a lid of the terminal electrode is suppressed, so that the gas can easily escape from the molten solder. As a result, voids in the solder after solidification can be reduced, so that a decrease in bonding strength is suppressed and the terminal electrode and the substrate electrode are electrically connected reliably. Moreover, the heat dissipation performance of the electronic component is improved, and the long-term reliability of the bonding between the terminal electrode and the substrate electrode can be ensured. Note that the configuration disclosed in the present embodiment can be applied as appropriate in the following embodiments, and those provided with the configuration disclosed in the present embodiment have the same operations and effects as the present embodiment.

(Embodiment 2)
FIG. 10 is a schematic diagram illustrating a mounting structure of an electronic component according to the second embodiment. FIG. 11 is a view as seen from the direction of the arrow X in FIG. The electronic component mounting structure (hereinafter referred to as a mounting structure) 10 is a structure used when the electronic component 1 according to the first embodiment is mounted on the substrate 3. In this mounting structure 10, of at least two terminal electrodes 2 provided in the electronic component 1, opposed end portions (long side end portions) 2 at 1 and 2 at 1 of at least one pair of terminal electrodes 2 a and 2 a facing each other are opposed to each other. The facing end portions (long side end portions) 4at1 and 4at1 of the substrate electrodes 4a and 4a respectively corresponding to the pair of terminal electrodes 2a and 2a overlap each other.

  In the present embodiment, the interval t1 between the end portions 2at1, 2at1 of the pair of terminal electrodes 2a, 2a facing each other is configured to be the same size as the interval t2 of the end portions 4at1, 4at1 of the substrate electrodes 4a, 4a facing each other. . The fact that the interval t1 and the interval t2 have the same dimension includes not only that they are completely the same, but also that the two dimensions are different due to dimensional tolerances and manufacturing errors. With this configuration, the end 2at1 of the terminal electrode 2a and the end 4at1 of the substrate electrode 4a corresponding to the terminal electrode 2a overlap, and as shown in FIG. 11, the end 2at1 of the terminal electrode 2a. And the end surface of the end portion 4at1 of the substrate electrode 4a are flush with each other. Note that the end 2at1 of the terminal electrode 2a and the end 4at1 of the substrate electrode 4a overlap with each other in addition to the fact that the end surface of the end 2at1 and the end surface of the end 4at1 are completely flush with each other. In addition, due to manufacturing error or the like, the both end faces are also shifted due to the fact that the interval t1 and the interval t2 are not completely the same.

  As described above, the end part 2at1 and the end part 4at1 are overlapped between the terminal electrodes 2a and 2a facing each other and the corresponding substrate electrodes 4a and 4a, whereby the longitudinal central axis ZL of the electronic component 1 is obtained. To the respective substrate electrodes 4a can be made substantially the same. Thereby, the imbalance of arrangement | positioning of the electronic component 1 with respect to the longitudinal direction center axis ZL is reduced, and the electrical property of the electronic component 1 becomes favorable. Here, the longitudinal center axis ZL is an axis parallel to the longitudinal direction of the electronic component 1 and passing through the center of the electronic component 1 in the short direction.

  In the mounting structure 10, the interval t1 between the terminal electrodes 2a and 2a is configured to have the same dimension as the interval t2 between the substrate electrodes 4a and 4a, so that the end portion 2at1 and the end portion 4at1 are separated in the reflow process. It will naturally overlap (self-alignment effect). As described above, since the function of automatically positioning the electronic component 1 to the predetermined positions of the substrate electrodes 4a and 4a on the substrate 3 can be obtained, the end 2at1 and the end 4at1 can be reliably and easily overlapped. .

  FIG. 12 is a schematic diagram illustrating a mounting structure according to another example of the second embodiment. The mounting structure 10a has the same configuration as the mounting structure 10 described above, but the number of terminal electrodes 2 of the electronic component 1 increases from four to six, and the corresponding number of substrate electrodes 4 also increases from four to six. The difference is that it is increasing. Also in this case, at least one pair of opposing end portions of the pair of opposing terminal electrodes 2a, 2a, 2b, 2b, 2c, and 2c, the corresponding substrate electrodes 4a, 4a, 4b, 4b, or What is necessary is just to comprise so that it may overlap with the edge part of 4c, 4c.

  FIG. 13 is a schematic diagram illustrating a mounting structure according to a modification of the second embodiment. The mounting structure 10b includes at least two terminal electrodes 2 included in the electronic component 1 and facing ends (short-side end portions) 2at2, 2bt2 of at least one pair of terminal electrodes 2a, 2b facing each other. The facing end portions (short side end portions) 4at2 and 4bt2 of the substrate electrodes 4a and 4b respectively corresponding to the pair of terminal electrodes 2a and 2b facing each other out of the terminal electrodes 2a and 2b overlap each other. Even in this way, the function of automatically positioning the electronic component 1 to the predetermined positions of the substrate electrodes 4a and 4b on the substrate 3 is obtained. Moreover, the imbalance of the arrangement of the electronic component 1 with respect to the central axis in the short direction is reduced, and the electrical characteristics of the electronic component 1 are improved. Here, the short direction central axis is an axis parallel to the short direction of the electronic component 1 and passing through the center of the electronic component 1 in the long direction.

  In the present embodiment, at least one pair of terminal electrodes and corresponding substrate electrodes may be configured such that the end portions of the terminal electrodes and the end portions of the substrate electrodes overlap. However, when the electronic component has two or more pairs of opposing terminal electrodes and the substrate has substrate electrodes corresponding thereto, two or more pairs of terminal electrodes and substrate electrodes corresponding to these pairs are provided. It is preferable that the end portion of the substrate and the end portion of the substrate electrode overlap each other. As a result, the function of automatically positioning the electronic component to a predetermined position of the substrate electrode on the substrate is more effectively exhibited.

  Further, as shown in FIG. 10, the opposing end portions of the pair of terminal electrodes 2a, 2a, or 2b, 2b are end portions parallel to the longitudinal direction of the terminal electrodes 2a, 2a, 2b, 2b, that is, long More preferably, the side end portions 2at1, 2at1, or 2bt1, 2bt1 are used. In this way, since the surface tension of the solder 5 that contacts the long side end portions 2at1, 2at1, etc. acts more, the long side end portions 2at1, 2at1 such as the terminal electrodes 2a, 2a are connected to the substrate electrode 4a. The action of trying to overlap the long side end portions 4at1 and 4at1 of 4a can be more effectively created. As a result, the function of automatically positioning the electronic component to a predetermined position of the substrate electrode on the substrate can be more effectively exhibited.

  FIG. 14 is a plan view showing the relationship between the terminal electrode and the substrate electrode. As shown in FIG. 14, the area (= h × w) of the terminal electrode 2 is preferably smaller than the area (= a × b) of the substrate electrode 4. In this way, when the electronic component is placed on the substrate, it is possible to allow displacement of the electronic component mounting position, and it is easy for gas to escape from the molten solder. Furthermore, since the area of the substrate electrode 4 is large, the amount of solder on the substrate electrode 4 increases, so that the solder is more likely to flow when melted. As a result, the gas is more easily released from the molten solder, which is more effective for reducing voids.

  Further, since a gap is formed between the substrate electrode 4 and the terminal electrode 2, when a force is applied in a direction parallel to the bonding surface of the terminal electrode 2 and the substrate electrode 4, the gap is accumulated in the gap. The terminal electrode 2 is supported by the solder. As a result, the bonding strength between the terminal electrode 2 and the substrate electrode 4 is improved. Therefore, when a force in a direction parallel to the plate surface of the substrate is applied to the electronic component, the electronic component is not easily detached from the substrate.

  In the example shown in FIG. 14, one end 2 t 1 of the terminal electrode 2 and one end 4 t of the substrate electrode 4 overlap. Since both the terminal electrode 2 and the substrate electrode 4 are rectangular in plan view, a gap is formed between the remaining ends of both. The size c of the gap is preferably 25 μm or more, and preferably 50 μm from the viewpoint of improving the bonding strength between the terminal electrode 2 and the substrate electrode 4. When c is larger than 50 μm, the bonding strength hardly changes. Therefore, it is sufficient that c is 50 μm at the maximum.

  As described above, in the present embodiment, the facing end portions of at least one pair of terminal electrodes facing each other out of at least two terminal electrodes and the facing end portions of the substrate electrodes respectively corresponding to the pair of facing terminal electrodes are overlapped. Structure. Thereby, the imbalance with respect to the longitudinal center axis of the electronic component is reduced, and the electrical characteristics of the electronic component are improved.

  As described above, the electronic component and the electronic device according to the present invention and the mounting structure of the electronic component are useful for mounting the surface mounting type electronic component and the electronic component.

DESCRIPTION OF SYMBOLS 1 Electronic component 1B Bottom face 2, 2a, 102 Terminal electrode 2at1, Long side edge part (edge part)
2t1 end 3 substrate 3P surface 4, 4a, 104 substrate electrode 4at1 long side end (end)
4t end portion 5 solder 5P solder paste 6 protrusion 10, 10a, 10b mounting structure

Claims (5)

In an electronic component having terminal electrodes exposed on the outer surface,
Having at least two terminal electrodes provided on the same surface;
The dimension of the electronic component in the longitudinal direction is 1005 M or less, the dimension of the terminal electrode in the lateral direction is 30 μm or more and 120 μm or less, and the ratio of the dimension in the lateral direction of the terminal electrode to the dimension in the longitudinal direction is 0.324. The electronic component is characterized by being 0.480 or less. The shape of the surface of the electronic component on which the at least two terminal electrodes are provided is a rectangle,
The electronic component according to claim 1, wherein the longitudinal direction of the surface is parallel to the longitudinal direction of the terminal electrode.   An electronic device comprising the electronic component according to claim 1. The terminal electrode is provided on the same surface and has at least two terminal electrodes exposed on the outer surface, has a lengthwise dimension of 1005M or less, a widthwise dimension of the terminal electrode is 30 μm or more and 120 μm or less, and the terminal electrode The ratio of the short side direction to the long side direction is 0.324 or more and 0.480 or less electronic component,
And at least two substrate electrodes provided on a mounting surface of the substrate on which the electronic component is mounted,
An end portion of at least one pair of terminal electrodes facing each other among the at least two terminal electrodes, and an end portion of substrate electrodes corresponding to the pair of terminal electrodes facing each other among the at least two substrate electrodes A mounting structure for electronic components, characterized by overlapping.   The mounting structure for an electronic component according to claim 4, wherein the facing end portions of the pair of terminal electrodes are end portions parallel to the longitudinal direction of the electrodes.

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