Electronic component package and electronic component mounting substrate

Abstract

The utility model provides a package for an electronic component and an electronic component mounting substrate. Bending, deflection and the like are easy to occur in a package for an electronic component. A package (10) for an electronic component is provided with: a first metal foil (11); a second metal foil (12); and a joint part (13) formed by joining the outer edge part of the first metal foil (11) and the outer edge part of the second metal foil (12). The length dimension of the bonding portion (13) in the direction along the outer edge portion of the first metal foil (11) is at least twice the width dimension of the bonding portion (13). The thickness dimension (D3) of the bonding portion (13) is larger than the sum of the thickness dimension (D1) of the first metal foil (11) and the thickness dimension (D2) of the second metal foil (12) over 90% or more of the entire range of the bonding portion (13) in the direction along the outer edge portion of the first metal foil (11).

Description

Technical Field

[0001] The utility model relates to an electronic component package, a method for manufacturing the electronic component package, and an electronic component mounting substrate. Background Art

[0002] The electronic component package disclosed in Patent Document 1 includes a first metal foil and a second metal foil. The first metal foil is quadrilateral in shape when viewed from above. The second metal foil has approximately the same shape and size as the first metal foil. The first and second metal foils overlap so that their outer edges are aligned. In addition, the electronic component package includes a joint formed by joining the outer edge of the first metal foil and the outer edge of the second metal foil. A closed space is defined by the first metal foil, the second metal foil, and the joint. Electronic components are stored in the closed space.

[0003] Patent Document 1: Japanese Patent No. 5377763

[0004] The electronic component package described in Patent Document 1 is essentially a structure consisting of two overlapping metal foils. Therefore, the electronic component package is susceptible to bending and warping. To prevent this, handling of the electronic component package requires certain measures. This can place an excessive burden on personnel handling the electronic component package. Utility Model Content

[0005] In order to solve the above-mentioned problems, the present invention is a package for electronic components, which comprises: a first metal foil; a second metal foil overlapping with the above-mentioned first metal foil; and a joint portion, which is a portion formed by joining the outer edge portion of the above-mentioned first metal foil and the outer edge portion of the above-mentioned second metal foil. When observed in a direction perpendicular to the main surface of the above-mentioned first metal foil, the length dimension of the above-mentioned joint portion in the direction along the above-mentioned outer edge portion of the above-mentioned first metal foil is more than twice the width dimension of the joint portion. When the maximum dimension in the direction perpendicular to the above-mentioned main surface when viewed in a cross-section perpendicular to the above-mentioned main surface is taken as the thickness dimension, in more than 90% of the entire range of the above-mentioned joint portion in the direction along the outer edge portion of the above-mentioned first metal foil, the above-mentioned thickness dimension of the above-mentioned joint portion is larger than the sum of the above-mentioned thickness dimension of the above-mentioned first metal foil and the above-mentioned thickness dimension of the above-mentioned second metal foil.

[0006] It may also be that, in more than 90% of the entire range of the above-mentioned joint in the direction along the outer edge of the above-mentioned first metal foil, the above-mentioned thickness dimension of the above-mentioned joint is larger than the sum of the above-mentioned thickness dimension of the above-mentioned first metal foil, the above-mentioned thickness dimension of the above-mentioned second metal foil, and 1 / 2 of the above-mentioned thickness dimension of the above-mentioned first metal foil, or larger than the sum of the above-mentioned thickness dimension of the above-mentioned first metal foil, the above-mentioned thickness dimension of the above-mentioned second metal foil, and 1 / 2 of the above-mentioned thickness dimension of the above-mentioned second metal foil.

[0007] The joining portion may extend continuously along the outer edge of the first metal foil over 25% or more of the outer edge.

[0008] The joining portion may extend continuously along the entire outer edge of the first metal foil.

[0009] It can also be that when the direction in which the first metal foil is located relative to the second metal foil in the direction perpendicular to the above-mentioned main surface is taken as the positive direction, when the cross-section is viewed perpendicular to the main surface of the above-mentioned first metal foil, the shape of the above-mentioned joint is a shape that protrudes toward the above-mentioned positive direction relative to the main surface of the above-mentioned first metal foil, and the surface of the above-mentioned joint facing the above-mentioned positive direction is arc-shaped.

[0010] When a direction opposite to the positive direction is defined as a negative direction, the joining portion may have a shape that is convex in the negative direction relative to the outer surface of the second metal foil.

[0011] In addition, the utility model is an electronic component mounting substrate, which comprises: a package for an electronic component; and a substrate on which the package for the electronic component is mounted, the package for the electronic component comprising: a first metal foil; a second metal foil overlapping the first metal foil; and a joint portion formed by joining an outer edge portion of the first metal foil and an outer edge portion of the second metal foil, wherein, when viewed in a direction perpendicular to a main surface of the first metal foil, a length dimension of the joint portion in a direction along the outer edge portion of the first metal foil is at least twice a width dimension of the joint portion, and when viewed in a direction perpendicular to the main surface, a length dimension of the joint portion in a direction perpendicular to the main surface is compared to a width dimension of the joint portion. With respect to the first metal foil, when the direction in which the second metal foil is located is taken as the negative direction, the surface of the joint portion on the negative direction side is fixed to the substrate, and when the maximum dimension in the direction perpendicular to the main surface when viewed in a cross-section perpendicular to the main surface is taken as the thickness dimension, in more than 90% of the entire range of the joint portion in the direction along the outer edge of the first metal foil, the thickness dimension of the joint portion is larger than the sum of the thickness dimension of the first metal foil and the thickness dimension of the second metal foil, and the shape of the joint portion is a shape that is convex toward the negative direction relative to the outer surface of the second metal foil.

[0012] In addition, the utility model is a method for manufacturing a package for an electronic component, which comprises: a preparation step, in which a first metal foil and a second metal foil overlapping with the first metal foil are prepared; and a joining step, in which a joint is formed by joining the outer edge of the first metal foil and the outer edge of the second metal foil, and in the joining step, the joint is formed by welding the outer edge of the first metal foil and the outer edge of the second metal foil in such a manner that, when the maximum dimension in a direction perpendicular to the main surface of the first metal foil when viewed in a cross-section perpendicular to the main surface is taken as the thickness dimension, the length dimension of the joint in a direction along the outer edge of the first metal foil is made more than twice the width dimension of the joint when viewed in a direction perpendicular to the main surface, and the thickness dimension of the joint is made greater than the sum of the thickness dimension of the first metal foil and the thickness dimension of the second metal foil in more than 90% of the entire range of the joint in the direction along the outer edge of the first metal foil.

[0013] According to the present invention, bending and deflection are less likely to occur in the electronic component package. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a perspective view of a package for electronic components.

[0015] Figure 2 It is an enlarged cross-sectional view of the joint.

[0016] Figure 3 This is a flow chart of a method for manufacturing a package for an electronic component.

[0017] Figure 4 This is a diagram illustrating a method for manufacturing a package for an electronic component.

[0018] Figure 5 This is a diagram illustrating a method for manufacturing a package for an electronic component.

[0019] Figure 6 This is a cross-sectional view of a substrate on which electronic components are mounted.

[0020] Figure 7 It is a perspective view of an electronic component package according to a modified example.

[0021] Description of Reference Numerals

[0022] PD…positive direction; ND…negative direction; 10…package for electronic component; 11…first metal foil; 12…second metal foil; 13…joining portion; MF…main surface; D1…thickness dimension; D2…thickness dimension; D3…thickness dimension; EB…electronic component mounting substrate; CB…substrate. DETAILED DESCRIPTION

[0023] <One embodiment of an electronic component package, a method for manufacturing the same, and an electronic component mounted substrate>

[0024] The following describes one embodiment of an electronic component package, a method for manufacturing an electronic component package, and an electronic component mounting substrate. The accompanying drawings are schematic diagrams for ease of understanding, and some components may be exaggerated or omitted. Consequently, the dimensional ratios of the components may differ from actual dimensions.

[0025] (Regarding the overall structure of the package for electronic components)

[0026] like Figure 1 As shown, the electronic component package 10 includes a first metal foil 11 and a second metal foil 12 .

[0027] The first metal foil 11 is a substantially square foil. The material of the first metal foil 11 is stainless steel. The first metal foil 11 has a main surface MF. The main surface MF is one of the largest surfaces of the first metal foil 11.

[0028] The first metal foil 11 has a first bonded portion 11A and a first non-bonded portion 11B. The first bonded portion 11A is the portion of the first metal foil 11 that is bonded to the second metal foil 12. The first bonded portion 11A extends over the entire outer edge of the first metal foil 11. Specifically, the first bonded portion 11A is a substantially square ring.

[0029] Here, the edge of the first bonding portion 11A located closer to the center of the main surface MF of the first metal foil 11 is referred to as the inner peripheral edge 14. The edge of the first bonding portion 11A located on the side opposite the center of the main surface MF relative to the inner peripheral edge 14 when viewed in a direction perpendicular to the main surface MF is referred to as the outer peripheral edge 15. The inner peripheral edge 14 is a quadrilateral. The outer peripheral edge 15 is aligned with the outer edge of the first metal foil 11. Therefore, the outer peripheral edge 15 is a quadrilateral.

[0030] When the electronic component package 10 is viewed in a direction perpendicular to the main surface MF, the shortest distance from any point on the outer periphery 15 to the inner periphery 14 is defined as the width W. The width W of the first bonding portion 11A is substantially uniform throughout the entire first bonding portion 11A.

[0031] The first non-joined portion 11B is a portion of the first metal foil 11 that is not joined to the second metal foil 12. In other words, the first non-joined portion 11B is the portion of the first metal foil 11 surrounded by the inner periphery 14 of the first joining portion 11A. Therefore, the first non-joined portion 11B has a rectangular planar shape. Furthermore, the first non-joined portion 11B can be separated from the second metal foil 12. The center of the first non-joined portion 11B is aligned with the center of the main surface MF of the first metal foil 11.

[0032] like Figure 1 As shown, the second metal foil 12 is a foil that is roughly quadrilateral. The material of the second metal foil 12 is stainless steel. The second metal foil 12 has a second bonding portion 12A and a second non-bonding portion 12B. The second bonding portion 12A is the portion of the second metal foil 12 that is bonded to the first metal foil 11. The second bonding portion 12A extends over roughly the entire outer edge of the second metal foil 12. That is, the second bonding portion 12A is roughly quadrilateral and annular. The shape of the second bonding portion 12A is consistent with that of the first bonding portion 11A. Therefore, the shape of the inner periphery 14 of the second bonding portion 12A is quadrilateral. The shape of the outer periphery 15 of the second bonding portion 12A is quadrilateral. In addition, the width dimension W of the second bonding portion 12A is roughly the same throughout the second bonding portion 12A. The thickness dimension of the second bonding portion 12A is roughly the same throughout the second bonding portion 12A.

[0033] The second non-joined portion 12B is a portion of the second metal foil 12 that is not joined to the first metal foil 11. In other words, the second non-joined portion 12B is the portion of the second metal foil 12 surrounded by the inner periphery 14 of the second joining portion 12A. Furthermore, the second non-joined portion 12B is separable from the first metal foil 11. The shape of the second non-joined portion 12B is the same as that of the first non-joined portion 11B.

[0034] Furthermore, the first metal foil 11 and the second metal foil 12 are welded together in the joining process S11 described later. Therefore, the first joining portion 11A is the portion formed by melting the first metal foil 11. The second joining portion 12A is the portion formed by melting the second metal foil 12. Furthermore, the first joining portion 11A and the second joining portion 12A are an integral body joined together. Therefore, a clear boundary between the first joining portion 11A and the second joining portion 12A may not be observed.

[0035] According to the above configuration, the electronic component package 10 has a closed space partitioned by the first metal foil 11 and the second metal foil 12. Although not shown in the figure, the electronic component package 10 stores a predetermined electronic component EC in the closed space.

[0036] (Regarding the shape of the joint)

[0037] As described above, the first joining portion 11A and the second joining portion 12A are an integral body formed by joining together. Hereinafter, the integral body of the first joining portion 11A and the second joining portion 12A will be described as the joining portion 13. Furthermore, the inner periphery 14 of the first joining portion 11A and the second joining portion 12A will be described as the inner periphery 14 of the joining portion 13. Similarly, the outer periphery 15 of the first joining portion 11A and the second joining portion 12A will be described as the outer periphery 15 of the joining portion 13. Therefore, the joining portion 13 is a portion formed by joining the outer periphery of the first metal foil 11 and the outer periphery of the second metal foil 12. The material of the joining portion 13 is the same as that of the first metal foil 11 and the second metal foil 12.

[0038] When viewed in a direction perpendicular to the main surface MF of the first metal foil 11, the length dimension of the joint 13 in the direction along the outer edge of the first metal foil 11 and the outer edge of the second metal foil 12 is more than twice the width dimension W of the joint 13. In addition, it is preferred that the joint 13 continuously extends over a range of more than 10% of each outer edge. It is more preferred that the joint 13 continuously extends over a range of more than 25% of each outer edge. It is further preferred that the joint 13 continuously extends over a range of more than 50% of each outer edge. In this embodiment, the joint 13 continuously extends over the entire range of each outer edge in the direction along the outer edge of the first metal foil 11 and the outer edge of the second metal foil 12.

[0039] like Figure 2 As shown, when the electronic component package 10 is viewed in a cross-section perpendicular to the main surface MF of the first metal foil 11, the maximum dimension of each component in the direction perpendicular to the main surface MF is used as the thickness dimension. For example, the thickness dimension D1 of the first metal foil 11 is the maximum dimension perpendicular to the main surface MF in a specific cross-section of the first metal foil 11. Therefore, the thickness dimension D1 of the first metal foil 11 may vary in different cross-sections. This also applies to the second metal foil 12 and the bonding portion 13.

[0040] The thickness dimension D3 of the joint 13 is substantially the same throughout the entire joint 13. Furthermore, the thickness dimension D3 of the joint 13 is greater than the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12. Specifically, the thickness dimension D3 of the joint 13 is greater than the sum of the thickness dimension D1 of the first metal foil 11, the thickness dimension D2 of the second metal foil 12, and 1 / 2 of the thickness dimension D1 of the first metal foil 11, or greater than the sum of the thickness dimension D1 of the first metal foil 11, the thickness dimension D2 of the second metal foil 12, and 1 / 2 of the thickness dimension D2 of the second metal foil 12. In this embodiment, the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12 are substantially the same. Therefore, the thickness dimension D3 of the joint 13 is at least 1.25 times the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12. Furthermore, the thickness dimension D3 of the joining portion 13 maintains the above-described relationship over 90% or more, specifically, approximately 100% of the entire range of the joining portion 13 in the direction along the outer edge of the first metal foil 11 .

[0041] Furthermore, the thickness dimension D1 of the first metal foil 11 is the thickness dimension D1 of the portion that is not bonded to the second metal foil 12 and has a clear boundary with respect to the second metal foil 12. In other words, the thickness dimension D1 of the first metal foil 11 is the thickness dimension D1 of the first non-bonded portion 11B. This also applies to the second metal foil 12. In other words, the thickness dimension D2 of the second metal foil 12 is the thickness dimension D2 of the second non-bonded portion 12B.

[0042] In addition, it can be confirmed in the following manner that the thickness dimension D1 of the first metal foil 11, the thickness dimension D2 of the second metal foil 12, and the thickness dimension D3 of the joint 13 satisfy the above relationship in more than 90% of the entire range of the joint 13. First, the joint 13 of the electronic component package 10 is cut in a direction perpendicular to the main surface MF of the first metal foil 11 and the cross-section is observed. At this time, it is determined whether the relationship of thickness dimension D3 ≥ (1.5×thickness dimension D1+thickness dimension D2) or thickness dimension D3 ≥ (thickness dimension D1+1.5×thickness dimension D2) is satisfied. This determination is performed on the cross-sections of 10 different locations of the joint 13. Moreover, if more than 90% of the cross-sections of the 10 locations satisfy the relationship between the thickness dimensions mentioned above, it can be said that the above relationship is satisfied in more than 90% of the entire range of the joint 13.

[0043] Here, the direction in which the first metal foil 11 is located relative to the second metal foil 12 in the direction perpendicular to the main surface MF is referred to as the positive direction PD. In addition, the opposite direction to the positive direction PD is referred to as the negative direction ND. When viewed in a cross-section perpendicular to the main surface MF of the first metal foil 11, the shape of the joint 13 is a shape that protrudes in the positive direction PD relative to the main surface MF of the first metal foil 11. Furthermore, the surface of the joint 13 facing the positive direction PD is arc-shaped. In addition, the "surface facing the positive direction PD" does not mean facing exactly in the positive direction PD, but only slightly facing the positive direction PD side. Specifically, when a vector perpendicular to the surface of the joint 13 and directed from the surface of the joint 13 toward the outside of the joint 13 is assumed, it is sufficient that the vector slightly contains a component in the positive direction PD. In addition, when viewed in the cross-section described above, the shape of the joint 13 is a shape that protrudes in the negative direction ND relative to the outer surface of the second metal foil 12. Furthermore, the surface of the joint 13 facing the negative direction ND is arc-shaped. In addition, the definition of the “surface facing the negative direction ND” is the same as that of the “surface facing the positive direction PD”.

[0044] Furthermore, the ratio of the thickness dimension D3 of the bonding portion 13 to the width dimension W of the bonding portion 13 (D3 / W) is greater than 0.8 and less than 1.2. Furthermore, when viewed in the cross-section described above, the surface of the bonding portion 13 reflects the aforementioned convex shape and dimension ratio of the bonding portion 13 and is generally circular. Furthermore, the shape of the bonding portion 13 is generally uniform along the outer edges of the respective metal foils, so the bonding portion 13 has a generally cylindrical ring shape extending along the outer edges of the respective metal foils.

[0045] (Method for manufacturing package for electronic components)

[0046] Next, a method for manufacturing the electronic component package 10 will be described. Figure 3 As shown, the method for manufacturing the electronic component package 10 includes a preparation step S10 and a bonding step S11 .

[0047] In the preparation step S10, Figure 4 As shown, first metal foil 11, second metal foil 12, and electronic components EC are prepared. Examples of electronic components EC include chip components for computing devices, batteries, inductors, capacitors, thermistors, and the like. In this state, first metal foil 11 does not have first joining portion 11A. Second metal foil 12 does not have second joining portion 12A. Next, electronic components EC are placed on the main surface of second metal foil 12. The first and second metal foils 11 and 12 are then overlapped so that they face each other.

[0048] After the preparation step S10, the bonding step S11 is performed. Figure 5As shown, in the joining step S11, a welding device WM is used to join the first metal foil 11 and the second metal foil 12. The welding device WM includes a laser device LA, a first support portion SB1, and a second support portion SB2. The laser device LA can output laser light according to preset output intensity, irradiation range, and irradiation time. The first support portion SB1 and the second support portion SB2 have mounting surfaces on which objects can be placed. The first support portion SB1 and the second support portion SB2 are arranged separately. In other words, the welding device WM has a gap between the first support portion SB1 and the second support portion SB2.

[0049] In the joining step S11, the first and second metal foils 11, 12 prepared in the preparation step S10 are first placed on the first and second supports SB1, SB2, of the welding apparatus WM. The metal foils are positioned so that the gap between the first and second supports SB1, SB2, is on the negative side ND of the area where the metal foils' joint 13 will be formed. In other words, the set of metal foils is placed on the mounting surfaces of the supports so that the areas to be joined, where the metal foils' joint 13 will be formed, do not come into contact with other objects, such as the supports.

[0050] Next, laser light is emitted from the laser device LA toward the main surface MF of the first metal foil 11, dissolving and welding the metal foil. This forms a joint 13 that continuously extends over at least 25% of the outer edge of the first metal foil 11. For at least 90% of the entire area of ​​the joint 13 along the outer edge of the first metal foil 11, the thickness D3 of the joint 13 is greater than the sum of the thickness D1 of the first metal foil 11 and the thickness D2 of the second metal foil 12. Furthermore, in the joining step S11, while the joint 13 is formed in the electronic component package 10, portions of each metal foil are partially separated from the electronic component package 10 to form fragments SP. Similar to the joint 13 in the electronic component package 10, even in these fragments SP, there is a portion where two metal foils are joined.

[0051] Specifically, the intensity distribution of the laser light output from the laser device LA is a Gaussian distribution. That is, in the intensity distribution of the laser light output, the intensity of the laser light is strongest at the center of the irradiation range, and the intensity decreases as it moves away from the center. Furthermore, the laser light is output in a pulsed manner to the main surface MF of the first metal foil 11. As a result, the outer edges of the metal foils melt at intervals of distance and time. The melted portions of the metal foils do not come into contact with other objects such as the supporting portion, so surface tension is generated in these portions. In other words, the shape of the melted portions is approximately spherical. Furthermore, by irradiating the laser light in a pulsed manner, the joint 13 becomes a shape formed by connecting multiple spherical tables along the outer edges of the metal foils. In other words, the joint 13 is formed into a roughly cylindrical ring shape extending along the outer edges of the metal foils. Therefore, the shape of the joint 13 becomes a shape that bulges in the positive direction PD relative to the main surface MF of the first metal foil 11. The shape of the joint 13 becomes a shape that bulges in the negative direction ND relative to the main surface MF of the first metal foil 11. Furthermore, in more than 90% of the entire range of the joint portion 13 in the direction along the outer edge of the first metal foil 11 , the thickness D3 of the joint portion 13 is larger than the sum of the thickness D1 of the first metal foil 11 and the thickness D2 of the second metal foil 12 .

[0052] In the joining step S11, the intensity and irradiation time of the laser light output from the laser device LA vary depending on the material and thickness of the metal foils to be welded. Therefore, the intensity and irradiation time of the laser light are determined in advance through experiments. The electronic component package 10 is manufactured by the above method.

[0053] (About electronic component mounting substrates)

[0054] Next, the substrate CB on which the above-mentioned electronic component package 10 is mounted, that is, the electronic component mounting substrate EB will be described. Figure 6 As shown, the electronic component mounting board EB includes a substrate CB and the above-mentioned electronic component package 10 .

[0055] The substrate CB is any printed circuit board, etc. The substrate CB is plate-shaped. Although not shown in the figure, chip components, electronic components, etc. are mounted on the substrate CB. The surface of the joint 13 of the electronic component package 10 on the negative direction ND side is fixed to the substrate CB. In addition, the joint 13 is joined to the substrate CB, so the joint surface of the joint 13 that is joined to the substrate CB is a plane that follows the surface shape of the substrate CB. In addition, even in the state of being joined to the substrate CB, the joint 13 is shaped to protrude in the negative direction ND relative to the outer surface of the second metal foil 12. Therefore, a gap is generated between the outer surface of the second metal foil 12 of the electronic component package 10 and the substrate CB. In other words, the outer surface of the second metal foil 12 and the substrate CB are not substantially in contact with each other. In addition, the joint 13 sometimes becomes part of the wiring that connects the internal electronic component EC and the circuit on the substrate CB.

[0056] (Effects of this embodiment)

[0057] (1) In the above embodiment, the thickness dimension D3 of the bonding portion 13 is greater than the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12 over more than 90% of the entire range of the bonding portion 13 in the direction along the outer edge of the first metal foil 11. In other words, the bonding portion 13 is thicker than the first non-bonding portion 11B and the second non-bonding portion 12B over almost the entire range along the above-mentioned outer edge. Therefore, the bonding portion 13 functions as a reinforcing column or reinforcing frame in the electronic component package 10. The presence of such a bonding portion 13 makes it less likely that the electronic component package 10 will bend or flex. Therefore, the handling of the electronic component package 10 becomes easier.

[0058] (2) In the above embodiment, the thickness D3 of the joint portion 13 is greater than the sum of the thickness D1 of the first metal foil 11, the thickness D2 of the second metal foil 12, and 1 / 2 of the thickness D1 of the first metal foil 11, or greater than the sum of the thickness D1 of the first metal foil 11, the thickness D2 of the second metal foil 12, and 1 / 2 of the thickness D2 of the second metal foil 12, over 90% or more of the entire extent of the joint portion 13 in the direction along the outer edge of the first metal foil 11. This significantly reduces the risk of bending or flexing in the electronic component package 10.

[0059] (3) In the above embodiment, the joint 13 continuously extends over a range of more than 25% of the outer edge of each metal foil. More specifically, the joint 13 continuously extends over the entire range of the outer edge in the direction along the outer edge of each metal foil. Thus, for example, when each metal foil is roughly square, the joint 13 has the function of a reinforcing column or a reinforcing frame over a range of more than one side of the metal foil. Moreover, the larger the range over which the joint 13 extends relative to the outer edge of the metal foil, the more enhanced the reinforcing function brought about by the joint 13. That is, the handling of the package 10 for electronic components becomes further facilitated.

[0060] (4) In the above embodiment, when viewed in a cross-section perpendicular to the main surface MF, the shape of the joint portion 13 is convex in the positive direction PD, and the surface of the joint portion 13 facing the positive direction PD is arc-shaped. The curved surface of the joint portion 13 can prevent damage to the joint portion 13 due to contact with other objects such as the substrate CB when the electronic component package 10 is mounted on the substrate CB. In addition, the trouble of cutting burrs during the manufacture of the electronic component package 10 is avoided.

[0061] (5) In the above embodiment, when viewed in a cross section perpendicular to the main surface MF, the shape of the bonding portion 13 is convex in the positive direction PD and convex in the negative direction ND relative to the outer surface of the second metal foil 12. Therefore, when the electronic component package 10 is mounted on the substrate CB, whether the bonding is performed with the positive direction PD side facing the substrate CB or with the negative direction ND side facing the substrate CB, the bonding portion 13 and the substrate CB can be easily brought into contact.

[0062] (6) In the above embodiment, in the electronic component mounting substrate EB, the shape of the joint portion 13 of the electronic component package 10 protrudes in the negative direction ND, and the surface of the joint portion 13 on the negative direction ND side is fixed to the substrate CB. As a result, a gap is generated between the second metal foil 12 and the substrate CB. Therefore, other electronic components, etc. can be mounted in this gap. In addition, even if the substrate CB is deformed, or the second metal foil 12 facing the substrate CB side is deformed, the space between the joint portion 13 and the substrate CB functions as a buffer space that allows the above deformation. That is, even if the substrate CB or the second metal foil 12 is slightly deformed, it is possible to prevent the substrate CB and the second metal foil 12 from accidentally contacting each other.

[0063] (7) In the above embodiment, in the joining step S11, the laser is output in a pulsed state. As a result, the outer edge portions of the metal foils are melted at intervals of distance and time. Therefore, the joining portion 13 has a shape formed by connecting a plurality of spherical tables. Therefore, when viewed in a cross-section in a direction perpendicular to the main surface MF, the surface of the joining portion 13 is likely to be arc-shaped. In addition, it is easy to make the thickness dimension D3 of the joining portion 13 larger than the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12.

[0064] <Change Example>

[0065] The above embodiment can be modified and implemented as follows: The above embodiment and the following modified examples can be implemented in combination with each other within the scope of no technical contradiction.

[0066] The shape and material of the first metal foil 11 are not limited to the examples in the above embodiment. For example, the material of the first metal foil 11 may be iron, aluminum, copper, etc. The same applies to the second metal foil 12. Furthermore, the material of the first metal foil 11 and the material of the second metal foil 12 may be different.

[0067] The electronic component package 10 may include a third metal foil in addition to the first metal foil 11 and the second metal foil 12. In this case, the joining portion 13 may join the outer edges of the three metal foils.

[0068] When viewed in a direction perpendicular to the main surface MF, the shape of the outer peripheral edge 15 and the shape of the inner peripheral edge 14 of the bonding portion 13 may not be a quadrilateral.

[0069] The joint 13 does not need to be continuous along the outer edge of the first metal foil 11 and the outer edge of the second metal foil 12. The joint 13 only needs to have a dimension along the outer edge of each metal foil that is at least twice the width W.

[0070] For example, Figure 7 As shown, the package 10 for electronic components may also include an electrode 20. A portion of the electrode 20, including one end, is sandwiched between the first metal foil 11 and the second metal foil 12. This one end of the electrode 20 is connected to the electronic component EC (not shown) stored inside. A portion of the other end side of the electrode 20 is exposed to the outside of the package 10 for electronic components. The electrode 20 is a conductive material. That is, the electrode 20 is electrically connected to the internal electronic component EC. The joint 13 is interrupted at the portion where the electrode 20 is exposed between the metal foils. That is, the joint 13 is discontinuous at this portion.

[0071] The width dimension W and thickness dimension D3 of the joint portion 13 are not limited to the examples in the above embodiment. The width dimension W of the joint portion 13 may not be substantially the same throughout. The thickness dimension D3 of the joint portion 13 may not be substantially the same throughout. Even if the thickness dimension D3 of the joint portion 13 varies locally in the direction in which the joint portion 13 extends, it is sufficient that the thickness dimension D3 of the joint portion 13 is greater than the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12 when viewed in a cross-section perpendicular to the main surface MF.

[0072] Furthermore, this dimensional relationship does not necessarily need to be satisfied at all locations. Specifically, the thickness D3 of the joint 13 may be locally less than or equal to the sum of the thickness D1 of the first metal foil 11 and the thickness D2 of the second metal foil 12. Even if there are locations where the thickness D3 is less than or equal to (thickness D1 + thickness D2), as long as this ratio is less than 10%, the joint 13 as a whole will function as a reinforcing column or frame.

[0073] Furthermore, the range in which the thickness dimension D3 of the joint portion 13 is greater than the sum of the thickness dimension D1 of the first metal foil 11, the thickness dimension D2 of the second metal foil 12, and 1 / 2 of the thickness dimension D1 of the first metal foil 11, or greater than the sum of the thickness dimension D1 of the first metal foil 11, the thickness dimension D2 of the second metal foil 12, and 1 / 2 of the thickness dimension D2 of the second metal foil 12, may not be greater than 90% of the entire range of the joint portion 13 in the direction along the outer edge of the first metal foil 11. For example, the range in which this relationship is satisfied may not exist in the joint portion 13.

[0074] When viewed in a cross-section perpendicular to the main surface MF of the first metal foil 11, the shape of the joint 13 need not be a shape that bulges in the positive direction PD relative to the main surface MF of the first metal foil 11. Furthermore, the shape of the joint 13 need not be a shape that bulges in the negative direction ND relative to the outer surface of the second metal foil 12. For example, the shape of the joint 13 may be a shape that bulges in the negative direction ND relative to the outer surface of the second metal foil 12, rather than a shape that bulges in the positive direction PD.

[0075] Furthermore, the surface of the joint portion 13 facing the positive direction PD may not be arc-shaped. The surface of the joint portion 13 facing the negative direction ND may not be arc-shaped. In other words, the surface of the joint portion 13 may not be substantially circular in the cross-sectional view. For example, even if the surface of the joint portion 13 is substantially quadrilateral in the cross-sectional view, at least the effect described in (1) can be obtained.

[0076] In the preparation step S10 , it is not necessary to prepare two metal foils. For example, a single metal foil may be folded, overlapped, and joined. In this case, the three outer edges excluding the folded-back sides may be joined.

[0077] In the joining step S11 , the method for forming the joint portion 13 is not limited to the examples in the above-described embodiment. For example, it is not limited to laser welding. Any method is acceptable as long as the metal foils can be joined together.

[0078] In the joining step S11, the control method for the laser device LA is not limited to the example in the above embodiment. As a result of the joining, the dimension of the joined portion 13 along the outer edges of the metal foils is at least twice the width W. Furthermore, the thickness D3 of the joined portion 13 along the outer edges of the first metal foil 11 is greater than the sum of the thickness D1 of the first metal foil 11 and the thickness D2 of the second metal foil 12 for at least 90% of the entire extent of the joined portion 13.

[0079] In the above embodiment, two electronic components EC may be placed on the main surface of the second metal foil 12 in the preparation step S10 and then melted and welded together in the joining step S11. In this way, multiple electronic component packages 10 can be manufactured through a single joining step S11.

[0080] The structure of the electronic component mounting substrate EB is not limited to the examples in the above embodiment. For example, there may not be a gap between the electronic component package 10 and the substrate CB. Furthermore, the outer surface of the second metal foil 12 and the substrate CB may be in contact with each other. For example, this contact may occur due to deformation of the substrate CB or deformation of the metal foil facing the substrate CB.

[0081] Notes

[0082] Technical ideas that can be grasped from the above-mentioned embodiments and modifications are described.

[0083] [1] A package for an electronic component, comprising: a first metal foil; a second metal foil overlapping the first metal foil; and a joint portion formed by joining the outer edge portion of the first metal foil and the outer edge portion of the second metal foil, wherein, when viewed in a direction perpendicular to the main surface of the first metal foil, the length dimension of the joint portion in the direction along the outer edge portion of the first metal foil is more than twice the width dimension of the joint portion, and when the maximum dimension in the direction perpendicular to the main surface when viewed in a cross section perpendicular to the main surface is taken as the thickness dimension, the thickness dimension of the joint portion is greater than the sum of the thickness dimension of the first metal foil and the thickness dimension of the second metal foil in more than 90% of the entire range of the joint portion in the direction along the outer edge portion of the first metal foil.

[0084] [2] A package for an electronic component according to [1], wherein, in more than 90% of the entire range of the joint portion in the direction along the outer edge of the first metal foil, the thickness dimension of the joint portion is greater than the sum of the thickness dimension of the first metal foil, the thickness dimension of the second metal foil, and 1 / 2 of the thickness dimension of the first metal foil, or greater than the sum of the thickness dimension of the first metal foil, the thickness dimension of the second metal foil, and 1 / 2 of the thickness dimension of the second metal foil.

[0085] [3] The electronic component package according to [1] or [2], wherein the joining portion continuously extends over 25% or more of the outer edge of the first metal foil in a direction along the outer edge of the first metal foil.

[0086] [4] The electronic component package according to any one of [1] to [3], wherein the joining portion extends continuously along the outer edge of the first metal foil over the entire outer edge.

[0087] [5] A package for an electronic component according to any one of [1] to [4], wherein, when the direction of the first metal foil relative to the second metal foil in a direction perpendicular to the main surface is taken as a positive direction, when the cross-section is viewed perpendicular to the main surface of the first metal foil, the shape of the joint is a shape that protrudes in the positive direction relative to the main surface of the first metal foil, and the surface of the joint facing the positive direction is an arc shape.

[0088] [6] The electronic component package according to [5], wherein, when the direction opposite to the positive direction is defined as a negative direction, the shape of the bonding portion is a shape that is convex in the negative direction relative to the outer surface of the second metal foil.

[0089] [7] An electronic component mounting substrate, comprising: a package for an electronic component; and a substrate on which the package for an electronic component is mounted, wherein the package for an electronic component comprises: a first metal foil; a second metal foil overlapping the first metal foil; and a joint portion formed by joining the outer edge portion of the first metal foil and the outer edge portion of the second metal foil, wherein, when viewed in a direction perpendicular to the main surface of the first metal foil, the length dimension of the joint portion in the direction along the outer edge portion of the first metal foil is at least twice the width dimension of the joint portion, and the second metal foil in the direction perpendicular to the main surface is formed by joining the outer edge portion of the first metal foil and the outer edge portion of the second metal foil. When the direction of the metal foil relative to the above-mentioned first metal foil is taken as the negative direction, the surface of the above-mentioned joint on the above-mentioned negative direction side is fixed to the above-mentioned substrate, and when the maximum dimension in the direction perpendicular to the above-mentioned main surface when viewed in a cross-section perpendicular to the above-mentioned main surface is taken as the thickness dimension, in more than 90% of the entire range of the above-mentioned joint in the direction along the outer edge of the above-mentioned first metal foil, the above-mentioned thickness dimension of the above-mentioned joint is larger than the sum of the above-mentioned thickness dimension of the above-mentioned first metal foil and the above-mentioned thickness dimension of the above-mentioned second metal foil, and the shape of the above-mentioned joint is a shape that is convex in the above-mentioned negative direction relative to the outer surface of the above-mentioned second metal foil.

[0090] [8] A method for manufacturing a package for an electronic component, comprising: a preparation step, in which a first metal foil and a second metal foil overlapping with the first metal foil are prepared; and a joining step, in which a joining portion is formed by joining the outer edge portion of the first metal foil and the outer edge portion of the second metal foil, and when the maximum dimension in a direction perpendicular to the main surface of the first metal foil when viewed in a cross section perpendicular to the main surface is taken as the thickness dimension, in the joining step, the outer edge portion of the first metal foil and the outer edge portion of the second metal foil are welded to form the joining portion so that: when viewed in a direction perpendicular to the main surface, the length dimension of the joining portion in the direction along the outer edge portion of the first metal foil is more than twice the width dimension of the joining portion, and in more than 90% of the entire range of the joining portion in the direction along the outer edge portion of the first metal foil, the thickness dimension of the joining portion is greater than the sum of the thickness dimension of the first metal foil and the thickness dimension of the second metal foil.

Claims

1. A package for electronic components, characterized in that: have: a first metal foil; a second metal foil overlapping the first metal foil; and The joining portion is a portion where the outer edge of the first metal foil and the outer edge of the second metal foil are joined. When viewed in a direction perpendicular to the main surface of the first metal foil, the length of the joining portion in a direction along the outer edge of the first metal foil is at least twice the width of the joining portion. When the maximum dimension in a direction perpendicular to the main surface when viewed in a cross section perpendicular to the main surface is taken as the thickness dimension, The thickness of the joint portion is greater than the sum of the thickness of the first metal foil and the thickness of the second metal foil over 90% or more of the entire range of the joint portion in a direction along the outer edge of the first metal foil.

2. The electronic component package according to claim 1, wherein In more than 90% of the entire range of the joint in the direction along the outer edge of the first metal foil, the thickness dimension of the joint is larger than the sum of the thickness dimension of the first metal foil, the thickness dimension of the second metal foil, and 1 / 2 of the thickness dimension of the first metal foil, or larger than the sum of the thickness dimension of the first metal foil, the thickness dimension of the second metal foil, and 1 / 2 of the thickness dimension of the second metal foil.

3. The electronic component package according to claim 1, wherein The joining portion continuously extends over 25% or more of the outer edge portion of the first metal foil in a direction along the outer edge portion of the first metal foil.

4. The electronic component package according to claim 1, wherein The joining portion extends continuously along the entire outer edge of the first metal foil.

5. The electronic component package according to claim 1, wherein When the direction perpendicular to the main surface is defined as the positive direction, the direction in which the first metal foil is located relative to the second metal foil, When viewed in a cross section perpendicular to the main surface of the first metal foil, the joining portion is convex in the positive direction relative to the main surface of the first metal foil, and the surface of the joining portion facing the positive direction is arc-shaped.

6. The electronic component package according to claim 5, wherein When the opposite direction of the positive direction is regarded as the negative direction, The joining portion has a shape that is convex in the negative direction relative to the outer surface of the second metal foil.

7. An electronic component mounting substrate, characterized in that: The invention comprises: a package for an electronic component; and a substrate on which the package for the electronic component is mounted. The electronic component package comprises: a first metal foil; a second metal foil overlapping the first metal foil; and The joining portion is a portion where the outer edge of the first metal foil and the outer edge of the second metal foil are joined. When viewed in a direction perpendicular to the main surface of the first metal foil, the length of the joining portion in a direction along the outer edge of the first metal foil is at least twice the width of the joining portion. When the direction perpendicular to the main surface is defined as the negative direction, the direction in which the second metal foil is located relative to the first metal foil, The surface of the bonding portion on the negative direction side is fixed to the substrate, When the maximum dimension in a direction perpendicular to the main surface when viewed in a cross section perpendicular to the main surface is taken as the thickness dimension, The thickness of the joint portion is greater than the sum of the thickness of the first metal foil and the thickness of the second metal foil over 90% or more of the entire range of the joint portion in a direction along the outer edge of the first metal foil. The joining portion has a shape that is convex in the negative direction relative to the outer surface of the second metal foil.

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