Package for electronic component, production method of package for electronic component, and electronic component mounting substrate

Abstract

To solve the problem that a package for an electronic component is easily bent and deformed.SOLUTION: A package for an electronic component 10 includes a first metal foil 11, a second metal foil 12, and a bonding portion 13 at which an outer edge portion of the first metal foil 11 and an outer edge portion of the second metal foil 12 are bonded to each other. A length dimension of the bonding portion 13 in the direction along the outer edge portion of the first metal foil 11 is twice or more the width dimension of the bonding portion 13. A thickness dimension D3 of the bonding portion 13 is larger than the sum of a thickness dimension D1 of the first metal foil 11 and a thickness dimension D2 of the second metal foil 12 in 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.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a package for electronic components, a method for manufacturing the package for electronic components, and an electronic component mounting substrate.

Background Art

[0002] The package for electronic components disclosed in Patent Document 1 includes a first metal foil and a second metal foil. The shape of the first metal foil is rectangular in plan view. The shape and size of the second metal foil are substantially the same as those of the first metal foil. The first metal foil and the second metal foil are overlapped so that their outer edges coincide with each other. Further, the package for electronic components includes a joint portion where the outer edge portion of the first metal foil and the outer edge portion of the second metal foil are joined. A sealed space is defined by the first metal foil, the second metal foil, and the joint portion. An electronic component is stored in the sealed space.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The package for electronic components described in Patent Document 1 basically has a structure in which two metal foils are overlapped. Therefore, the package for electronic components is likely to be bent or deformed. In order to suppress such bending and deformation of the package for electronic components, some measures are required in the handling of the package for electronic components. Therefore, it may impose an excessive burden on those who handle the package for electronic components.

Means for Solving the Problems

[0005] To solve the above problems, the present invention provides an electronic component package including a first metal foil, a second metal foil overlapping the first metal foil, and a joint 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 dimension of the joint portion in the direction along the outer edge of the first metal foil is at least twice the width dimension of the joint portion. When the maximum dimension in the direction perpendicular to the main surface is defined as the thickness dimension in a cross-sectional view taken along a plane perpendicular to the main surface, in at least 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 and the thickness dimension of the second metal foil.

[0006] The present invention also provides an electronic component mounting substrate including an electronic component package and a substrate on which the electronic component package is mounted. The electronic component package includes a first metal foil, a second metal foil overlapping the first metal foil, and a joint 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 dimension of the joint portion in the direction along the outer edge of the first metal foil is at least twice the width dimension of the joint portion. When the direction in which the second metal foil is located with respect to the first metal foil is defined as the negative direction among the directions perpendicular to the main surface, the surface on the negative direction side of the joint portion is fixed to the substrate. When the maximum dimension in the direction perpendicular to the main surface is defined as the thickness dimension in a cross-sectional view taken along a plane perpendicular to the main surface, 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 at least 90% of the entire range of the joint portion in the direction along the outer edge of the first metal foil, and the shape of the joint portion is convex in the negative direction with respect to the outer surface of the second metal foil.

[0007] Further, the present invention includes a preparation step of preparing a first metal foil and a second metal foil overlapping the first metal foil, and a joining step of forming a joint by joining the outer edge portion of the first metal foil and the outer edge portion of the second metal foil. When the maximum dimension in the direction orthogonal to the main surface is defined as the thickness dimension in a cross-sectional view taken along a cross-section orthogonal to the main surface of the first metal foil, in the joining step, when viewed in the direction orthogonal to the main surface, the length dimension of the joint in the direction along the outer edge portion of the first metal foil is 2 times or more the width dimension of the joint, and in 90% or more of the entire range of the joint in the direction along the outer edge portion 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 and the thickness dimension of the second metal foil. The outer edge portion of the first metal foil and the outer edge portion of the second metal foil are welded to form the joint, which is a method for manufacturing an electronic component package.

Effects of the Invention

[0008] It is difficult for the electronic component package to be folded, bent, etc.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] <An Embodiment of a Package for Electronic Components, a Method for Manufacturing the Same, and an Electronic Component Mounting Substrate> Hereinafter, an embodiment of a package for electronic components, a method for manufacturing the package for electronic components, and an electronic component mounting substrate will be described. Note that the drawings are schematic diagrams for easy understanding, and components may be enlarged or omitted. Therefore, the dimensional ratios of the components may be different from the actual ones.

[0011] (Regarding the overall configuration of the package for electronic components) As shown in FIG. 1, the package 10 for electronic components includes a first metal foil 11 and a second metal foil 12.

[0012] The first metal foil 11 is a substantially rectangular 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 surfaces of the first metal foil 11 having the largest area.

[0013] The first metal foil 11 has a first joint portion 11A and a first non-joint portion 11B. The first joint portion 11A is a portion of the first metal foil 11 that is joined to the second metal foil 12. The first joint portion 11A extends over the entire outer edge of the first metal foil 11. That is, the first joint portion 11A is substantially rectangular and annular.

[0014] Here, among the edges of the first joint portion 11A, the edge located on the center side of the main surface MF of the first metal foil 11 is defined as the inner peripheral edge 14. When viewing the package 10 for electronic components in the direction perpendicular to the main surface MF, the edge located on the opposite side of the center of the main surface MF with respect to the inner peripheral edge 14 is defined as the outer peripheral edge 15. The shape of the inner peripheral edge 14 is rectangular. The outer peripheral edge 15 coincides with the outer edge of the first metal foil 11. Therefore, the shape of the outer peripheral edge 15 is rectangular.

[0015] Note that when viewing the package 10 for electronic components in the direction perpendicular to the main surface MF, the shortest distance from an arbitrary point on the outer peripheral edge 15 to the inner peripheral edge 14 is defined as the width dimension W. The width dimension W of the first joint portion 11A is substantially the same throughout the first joint portion 11A.

[0016] The first non-bonding portion 11B is the portion of the first metal foil 11 that is not bonded to the second metal foil 12. In other words, the first non-bonding portion 11B is the portion of the first metal foil 11 surrounded by the inner peripheral edge 14 of the first bonding portion 11A. Therefore, the first non-bonding portion 11B has a square planar shape. And the first non-bonding portion 11B can be separated from the second metal foil 12. The center of the first non-bonding portion 11B coincides with the center of the main surface MF of the first metal foil 11.

[0017] As shown in FIG. 1, the second metal foil 12 is a substantially square foil. 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 substantially the entire outer edge portion of the second metal foil 12. That is, the second bonding portion 12A is a substantially square ring shape. The shape of the second bonding portion 12A coincides with that of the first bonding portion 11A. Therefore, the shape of the inner peripheral edge 14 of the second bonding portion 12A is a square shape. The shape of the outer peripheral edge 15 of the second bonding portion 12A is a square shape. Also, the width dimension W of the second bonding portion 12A is substantially the same throughout the second bonding portion 12A. The thickness dimension of the second bonding portion 12A is substantially the same throughout the second bonding portion 12A.

[0018] The second non-bonding portion 12B is the portion of the second metal foil 12 that is not bonded to the first metal foil 11. In other words, the second non-bonding portion 12B is the portion of the second metal foil 12 surrounded by the inner peripheral edge 14 of the second bonding portion 12A. And the second non-bonding portion 12B can be separated from the first metal foil 11. The shape of the second non-bonding portion 12B is the same as that of the first non-bonding portion 11B.

[0019] Note that the first metal foil 11 and the second metal foil 12 are welded in the bonding step S11 described later. Therefore, the first joint 11A is a portion where the first metal foil 11 has melted. The second joint 12A is a portion where the second metal foil 12 has melted. And the first joint 11A and the second joint 12A are an integrated object joined to each other. Therefore, it may not be possible to observe a clear boundary between the first joint 11A and the second joint 12A.

[0020] With the above configuration, the electronic component package 10 has a sealed space partitioned by the first metal foil 11 and the second metal foil 12. Although not shown, the electronic component package 10 stores a predetermined electronic component EC in the sealed space.

[0021] (Regarding the shape of the joint) As described above, the first joint 11A and the second joint 12A are an integrated object joined to each other. Hereinafter, the integrated object of the first joint 11A and the second joint 12A will be described as the joint 13. Also, the inner peripheral edge 14 of the first joint 11A and the second joint 12A will be described as the inner peripheral edge 14 of the joint 13. Similarly, the outer peripheral edge 15 of the first joint 11A and the second joint 12A will be described as the outer peripheral edge 15 of the joint 13. Therefore, the joint 13 is a portion where the outer edge portion of the first metal foil 11 and the outer edge portion of the second metal foil 12 are joined. The material of the joint 13 is the same as the materials of the first metal foil 11 and the second metal foil 12.

[0022] When viewed in a direction orthogonal to the main surface MF of the first metal foil 11, the length dimension of the joint portion 13 in the direction along the outer edge portion of the first metal foil 11 and the outer edge portion of the second metal foil 12 is twice or more the width dimension W of the joint portion 13. Preferably, the joint portion 13 may continuously extend over a range of 10% or more of each outer edge portion. More preferably, the joint portion 13 may continuously extend over a range of 25% or more of each outer edge portion. Even more preferably, the joint portion 13 may continuously extend over a range of 50% or more of each outer edge portion. In the present embodiment, the joint portion 13 continuously extends over the entire range of each outer edge portion in the direction along the outer edge portion of the first metal foil 11 and the outer edge portion of the second metal foil 12.

[0023] As shown in FIG. 2, when the electronic component package 10 is viewed in cross section in a cross section orthogonal to the main surface MF of the first metal foil 11, the maximum dimension of each component in the direction orthogonal to the main surface MF is taken as the thickness dimension. For example, the thickness dimension D1 of the first metal foil 11 is the maximum dimension of the first metal foil 11 in the direction orthogonal to the main surface MF in a specific cross section. Therefore, in different cross sections, the thickness dimension D1 of the first metal foil 11 may be different. The same applies to the second metal foil 12 and the joint portion 13 in this regard.

[0024] The thickness dimension D3 of the joint portion 13 is substantially the same throughout the joint portion 13. Also, the thickness dimension D3 of the joint 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. Specifically, the thickness dimension D3 of the joint portion 13 is larger 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 1 / 2 of the thickness dimension D2 of the second metal foil 12. In the present 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 portion 13 is 1.25 times or more the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12. Note that the thickness dimension D3 of the joint portion 13 is 90% or more, specifically substantially 100%, of the entire range of the joint portion 13 in the direction along the outer edge portion of the first metal foil 11, and has the above relationship.

[0025] Note that the thickness dimension D1 of the first metal foil 11 is the thickness dimension D1 at a portion that is not joined to the second metal foil 12 and has a clear boundary with the second metal foil 12. That is, the thickness dimension D1 of the first metal foil 11 is the thickness dimension D1 at the first non-joined portion 11B. The same applies to the second metal foil 12. That is, the thickness dimension D2 of the second metal foil 12 is the thickness dimension D2 at the second non-joined portion 12B.

[0026] Also, it can be confirmed as follows 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 portion 13 satisfy the above relationship in 90% or more of the entire range of the joint portion 13. First, the joint portion 13 of the electronic component package 10 is cut in a direction orthogonal 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 made for the cross sections of 10 different joint portions 13. And if the relationship between the above thickness dimensions is satisfied in 90% or more of the 10 cross sections, it can be said that the above relationship is satisfied in 90% or more of the entire range of the joint portion 13.

[0027] Here, among the directions orthogonal to the main surface MF, the direction in which the first metal foil 11 is located with respect to the second metal foil 12 is defined as the positive direction PD. Also, the direction opposite to the positive direction PD is defined as the negative direction ND. When viewed in cross-section in a cross-section orthogonal to the main surface MF of the first metal foil 11, the shape of the joint portion 13 is convex in the positive direction PD with respect to the main surface MF of the first metal foil 11. And, the surface of the joint portion 13 facing the positive direction PD is arc-shaped. Note that the "surface facing the positive direction PD" does not exactly mean facing the positive direction PD, but only needs to face the positive direction PD side even slightly. Specifically, when a vector orthogonal to the surface of the joint portion 13 and directed from the surface of the joint portion 13 to the outside of the joint portion 13 is imagined, it is sufficient if the vector contains even a slight positive direction PD component. Also, when viewed in cross-section in the above cross-section, the shape of the joint portion 13 is convex in the negative direction ND with respect to the outer surface of the second metal foil 12. And, the surface of the joint portion 13 facing the negative direction ND is arc-shaped. Note that the definition of the "surface facing the negative direction ND" is the same as that of the "surface facing the positive direction PD".

[0028] Also, the ratio (D3 / W) of the thickness dimension D3 of the joint portion 13 to the width dimension W of the joint portion 13 is 0.8 or more and less than 1.2. And, reflecting the convex shape and the dimensional ratio of the joint portion 13 as described above, in the cross-sectional view in the above cross-section, the surface of the joint portion 13 is substantially circular. And, since the shape of the joint portion 13 is substantially the same in the direction along the outer edge of each metal foil, the joint portion 13 is a substantially cylindrical ring extending in the direction along the outer edge of each metal foil.

[0029] (Method for manufacturing an electronic component package) Next, a method for manufacturing the electronic component package 10 will be described. As shown in FIG. 3, the method for manufacturing the electronic component package 10 includes a preparation step S10 and a bonding step S11.

[0030] In the preparation step S10, as shown in FIG. 4, a first metal foil 11, a second metal foil 12, and an electronic component EC are prepared. The electronic component EC is, for example, a chip component such as an arithmetic unit, a battery, an inductor, a capacitor, a thermistor, or the like. In this state, the first metal foil 11 does not have a first joint portion 11A. The second metal foil 12 does not have a second joint portion 12A. Next, the electronic component EC is placed on the main surface of the second metal foil 12. Then, the first metal foil 11 and the second metal foil 12 are overlapped so that the first metal foil 11 and the second metal foil 12 face each other.

[0031] After the preparation step S10, a joining step S11 is performed. As shown in FIG. 5, in the joining step S11, the first metal foil 11 and the second metal foil 12 are joined using a welding device WM. 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 a laser according to a preset output intensity, irradiation range, irradiation time, and the like. The first support portion SB1 and the second support portion SB2 have a placement surface on which an object can be placed on the upper surface. The first support portion SB1 and the second support portion SB2 are arranged apart from each other. In other words, the welding device WM has a gap between the first support portion SB1 and the second support portion SB2.

[0032] In the joining step S11, first, the first metal foil 11 and the second metal foil 12 prepared in the preparation step S10 are placed on the first support portion SB1 and the second support portion SB2 of the welding device WM. At this time, each metal foil is placed so that the gap between the first support portion SB1 and the second support portion SB2 is located on the negative direction ND side of the location where the joint portion 13 of the metal foil is to be formed. In other words, the pair of metal foils is placed on the placement surface of each support portion so that the joint target location where the joint portion 13 of the pair of metal foils is to be formed does not contact other objects such as each support portion.

[0033] Next, by outputting a laser from the laser device LA to the main surface MF of the first metal foil 11, fusing and welding of the metal foil are performed. As a result, the joint portion 13 extends continuously over a range of 25% or more of the outer edge portion in the direction along the outer edge portion of the first metal foil 11, and in 90% or more of the entire range of the joint portion 13 in the direction along the outer edge portion of the first metal foil 11, the thickness dimension D3 of the joint portion 13 is made 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, thereby forming the joint portion 13. In the joining step S11, while the joint portion 13 is formed in the electronic component package 10, a part of each metal foil is separated as a cut end SP from the electronic component package 10. Also at this cut end SP, a portion where the two metal foils are joined is generated in the same manner as the joint portion 13 of the electronic component package 10.

[0034] Specifically, the intensity distribution of the laser output from the laser device LA is a Gaussian distribution. That is, in the intensity distribution of the laser output, the intensity of the laser is the strongest at the center of the irradiation range and weakens as the distance from the center increases. Further, the laser is output in a pulsed manner to the main surface MF of the first metal foil 11. As a result, the outer edge portions of the respective metal foils melt at intervals of distance and time. Since the melted portions of the metal foil do not contact other objects such as a support portion, surface tension is generated in the portions. That is, the shape of the melted portion approaches a substantially spherical shape. Then, by irradiating the laser in a pulsed manner, the joint portion 13 has a shape in which a plurality of frustums of a cone are connected along the outer edge portions of the respective metal foils. In other words, the joint portion 13 is formed in an annular shape of a substantially cylinder extending along the outer edge portions of the respective metal foils. Therefore, the shape of the joint portion 13 is convex in the positive direction PD with respect to the main surface MF of the first metal foil 11. The shape of the joint portion 13 is convex in the negative direction ND with respect to the main surface MF of the first metal foil 11. Also, in 90% or more of the entire range of the joint portion 13 in the direction along the outer edge portion of the first metal foil 11, the thickness dimension D3 of the joint 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.

[0035] Note that the intensity and irradiation time of the laser output from the laser device LA in the bonding step S11 vary depending on the material and thickness of each metal foil to be welded. Therefore, the intensity and irradiation time of the laser are determined in advance through experiments. The electronic component package 10 is manufactured by the above method.

[0036] (Regarding the electronic component mounting substrate) Next, an electronic component mounting substrate EB, which is a substrate CB on which the above-described electronic component package 10 is mounted, will be described. As shown in FIG. 6, the electronic component mounting substrate EB includes the substrate CB and the above-described electronic component package 10.

[0037] The substrate CB is an arbitrary printed circuit board or the like. The substrate CB is plate-shaped. Although not shown, chip components, electronic components, etc. are mounted on the substrate CB. The bonding portion 13 of the electronic component package 10 has the surface on the negative direction ND side fixed to the substrate CB. Since the bonding portion 13 is bonded to the substrate CB, the bonding surface of the bonding portion 13 with the substrate CB is a planar shape following the surface shape of the substrate CB. Also, even in the state of being bonded to the substrate CB, the bonding portion 13 has a shape convex in the negative direction ND with respect 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. Note that the bonding portion 13 may also be a part of the wiring that conducts the internal electronic component EC and the circuit on the substrate CB.

[0038] (Regarding the effects of this embodiment) (1) In the above-described embodiment, in 90% or more of the entire range of the joint portion 13 in the direction along the outer edge portion of the first metal foil 11, the thickness dimension D3 of the joint 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. In other words, the joint portion 13 is thicker than the first non-joint portion 11B and the second non-joint portion 12B in almost the entire range in the direction along the outer edge portion. Therefore, the joint portion 13 has a function as a reinforcing pillar or a reinforcing frame in the electronic component package 10. The presence of such a joint portion 13 makes it less likely for the electronic component package 10 to break or bend. Therefore, the handling of the electronic component package 10 becomes easier.

[0039] (2) In the above-described embodiment, in 90% or more of the entire range of the joint portion 13 in the direction along the outer edge portion of the first metal foil 11, the thickness dimension D3 of the joint portion 13 is larger 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 1 / 2 of the thickness dimension D2 of the second metal foil 12. As a result, it becomes even less likely for the electronic component package 10 to break or bend significantly.

[0040] (3) In the above-described embodiment, the joint portion 13 extends continuously over a range of 25% or more of the outer edge portion of each metal foil. More specifically, the joint portion 13 extends continuously over the entire range of the outer edge portion in the direction along the outer edge portion of each metal foil. Thus, for example, when each metal foil is substantially square, the joint portion 13 has a function as a reinforcing pillar or a reinforcing frame over one side or more of the metal foil. And the wider the range in which the joint portion 13 extends with respect to the outer edge portion of the metal foil, the more the reinforcing function by the joint portion 13 is improved. That is, the handling of the electronic component package 10 becomes even easier.

[0041] (4) In the above-described embodiment, when viewed in cross-section in a cross-section orthogonal 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. Since the surface of the joint portion 13 is curved, when mounting the electronic component package 10 on the substrate CB or the like, it is possible to prevent the joint portion 13 from being damaged by contacting the substrate CB or other objects. Further, when manufacturing the electronic component package 10, the labor of cutting so-called burrs can be saved.

[0042] (5) In the above-described embodiment, when viewed in cross-section in a cross-section orthogonal to the main surface MF, the shape of the joint portion 13 is convex in the positive direction PD, and is convex in the negative direction ND with respect to the outer surface of the second metal foil 12. Thereby, when mounting the electronic component package 10 on the substrate CB, whether joining with the positive direction PD side facing the substrate CB or joining with the negative direction ND side facing the substrate CB, it is easy to bring the joint portion 13 into contact with the substrate CB.

[0043] (6) In the above-described embodiment, in the electronic component mounting substrate EB, the shape of the joint portion 13 of the electronic component package 10 is convex in the negative direction ND, and the surface on the negative direction ND side of the joint portion 13 is fixed to the substrate CB. As a result, a gap is formed between the second metal foil 12 and the substrate CB. Therefore, other electronic components or the like can be mounted in the gap. Further, even if the substrate CB is distorted or the second metal foil 12 facing the substrate CB side is distorted, the space between the joint portion 13 and the substrate CB functions as a buffer space that allows the above-described distortion. That is, even if the substrate CB or the second metal foil 12 is somewhat distorted, it is possible to prevent the substrate CB and the second metal foil 12 from accidentally contacting each other.

[0044] (7) In the above-described embodiment, in the bonding step S11, the laser is output in a pulsed manner. As a result, the outer edge portions of the respective metal foils melt with a distance and a time interval therebetween. Therefore, the joint portion 13 has a shape in which a plurality of spherical frustums are connected. Accordingly, in a cross-sectional view in a direction orthogonal to the main surface MF, the surface of the joint portion 13 is likely to be arc-shaped. Also, it is easy to make the thickness dimension D3 of the joint 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.

[0045] <Modified Example> The above-described embodiment can be implemented with the following modifications. The above-described embodiment and the following modified examples can be implemented in combination with each other within a range where there is no technical contradiction.

[0046] · The shape and material of the first metal foil 11 are not limited to the examples of the above-described embodiment. For example, the material of the first metal foil 11 may be iron, aluminum, copper, or the like. The same applies to the second metal foil 12 in these respects. Also, the material of the first metal foil 11 and the material of the second metal foil 12 do not have to be the same.

[0047] · The electronic component package 10 may have a third metal foil in addition to the first metal foil 11 and the second metal foil 12. In this case, the joint portion 13 only needs to join the outer edge portions of the three metal foils to each other.

[0048] · When viewed in a direction facing the direction orthogonal to the main surface MF, the shape of the outer peripheral edge 15 and the shape of the inner peripheral edge 14 of the joint portion 13 do not have to be rectangular. · In the direction along the outer edge portions of the first metal foil 11 and the second metal foil 12, the joint portion 13 does not have to continuously extend over the entire range of each outer edge portion. It is sufficient that the dimension of the joint portion 13 in the direction along the outer edge portion of each metal foil is at least twice the width dimension W.

[0049] For example, as shown in FIG. 7, the package 10 for electronic components may include electrodes 20. A part including one end of the electrode 20 is sandwiched between the first metal foil 11 and the second metal foil 12. The said one end of the electrode 20 is connected to an electronic component EC (not shown) stored inside. A part on 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 substance. That is, the electrode 20 is electrically connected to the internal electronic component EC. At the location where the electrode 20 is exposed from between the metal foils, the joint portion 13 is interrupted. That is, the joint portion 13 is not continuous at this location.

[0050] · Regarding the width dimension W and the thickness dimension D3 of the joint portion 13, it is not limited to the example of the above embodiment. The width dimension W of the joint portion 13 does not have to be substantially the same throughout. The thickness dimension D3 of the joint portion 13 does not have to be substantially the same throughout. Even if the thickness dimension D3 of the joint portion 13 is partially different in the direction in which the joint portion 13 extends, when viewed in cross-section in a cross-section perpendicular to the main surface MF, it may be 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.

[0051] Also, it is not necessary to satisfy this dimensional relationship at all locations. That is, the thickness dimension D3 of the joint portion 13 may be partially less than or equal to the sum of the thickness dimension D1 of the first metal foil 11 and the thickness dimension D2 of the second metal foil 12. Even if there is a location where the thickness dimension D3 ≤ (thickness dimension D1 + thickness dimension D2), as long as the ratio is less than 10%, the joint portion 13 as a whole functions as a reinforcing pillar or a reinforcing frame.

[0052] Furthermore, the range in which the thickness dimension D3 of the joint portion 13 is larger 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 1 / 2 of the thickness dimension D2 of the second metal foil 12 does not have to be 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. For example, there may be no range in the joint portion 13 that satisfies this relationship.

[0053] · When viewed in cross-section perpendicular to the main surface MF of the first metal foil 11, the shape of the joint 13 does not have to be convex in the positive direction PD with respect to the main surface MF of the first metal foil 11. Also, the shape of the joint 13 does not have to be convex in the negative direction ND with respect to the outer surface of the second metal foil 12. For example, the shape of the joint 13 may not be convex in the positive direction PD and may be convex in the negative direction ND with respect to the outer surface of the second metal foil 12.

[0054] Also, the surface facing the positive direction PD in the joint 13 does not have to be arc-shaped. The surface facing the negative direction ND in the joint 13 does not have to be arc-shaped. In other words, in the above cross-sectional view, the surface of the joint 13 does not have to be substantially circular. For example, even if it is substantially square in the above cross-sectional view, at least the effect described in (1) can be obtained.

[0055] · In the preparation step S10, it is not necessary to prepare two metal foils. For example, one metal foil may be folded, overlapped, and joined. In this case, the three outer edge portions excluding the folded side may be joined to each other.

[0056] · In the joining step S11, the method for forming the joint 13 is not limited to the examples of the above embodiment. For example, it is not limited to welding by laser. Any method can be used as long as the metal foils can be joined.

[0057] · In the joining step S11, the control method of the laser device LA is not limited to the examples of the above embodiment. As a result of the joining, the dimension in the direction along the outer edge portion of each metal foil of the joint 13 only needs to be at least twice the width dimension W or more. Moreover, the thickness dimension D3 of the joint 13 only needs to be 90% or more of the entire range of the joint 13 in the direction along the outer edge portion of the first metal foil 11 and 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.

[0058] ·In the above embodiment, in the preparation step S10, two electronic components EC may be placed on the main surface of the second metal foil 12, and in the bonding step S11, the space between the two electronic components EC may be severed and welded. Thereby, a plurality of electronic component packages 10 can be manufactured in a single bonding step S11.

[0059] ·The configuration of the electronic component mounting substrate EB is not limited to the example of the above embodiment. For example, there may be no gap between the electronic component package 10 and the substrate CB. Further, the outer surface of the second metal foil 12 and the substrate CB may be in contact with each other. For example, they may be in contact with each other due to distortion of the substrate CB or distortion of the metal foil facing the substrate CB side.

[0060] <Appended Note> The technical idea understood from the above embodiment and the modification example will be described. [1] An electronic component package including a first metal foil, a second metal foil overlapping the first metal foil, and a joint portion which is a portion where an outer edge portion of the first metal foil and an outer edge portion of the second metal foil are joined. When viewed in a direction orthogonal 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 2 times or more the width dimension of the joint portion. When the maximum dimension in the direction orthogonal to the main surface is defined as the thickness dimension in a cross-sectional view taken along a cross-section orthogonal to the main surface, in 90% or more of the entire range of the joint portion in the direction along the outer edge portion 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.

[0061] [2] The electronic component package according to [1], wherein in 90% or more of the entire range of the joint portion in the direction along the outer edge portion 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, the thickness dimension of the second metal foil, and 1 / 2 of the thickness dimension of the first metal foil or 1 / 2 of the thickness dimension of the second metal foil.

[0062] [3] The joint extends continuously over a range of 25% or more of the outer edge of the first metal foil in the direction along the outer edge of the first metal foil. The electronic component package according to [1] or [2]. [4] The joint extends continuously over the entire range of the outer edge of the first metal foil in the direction along the outer edge of the first metal foil. The electronic component package according to any one of [1] to [3].

[0063] [5] When the direction in which the first metal foil is located with respect to the second metal foil is defined as the positive direction among the directions orthogonal to the main surface, in a cross-sectional view taken along a cross-section orthogonal to the main surface of the first metal foil, the shape of the joint is convex in the positive direction with respect to the main surface of the first metal foil, and the surface of the joint facing the positive direction is arcuate. The electronic component package according to any one of [1] to [4].

[0064] [6] When the direction opposite to the positive direction is defined as the negative direction, the shape of the joint is convex in the negative direction with respect to the outer surface of the second metal foil. The electronic component package according to [5].

[0065] [7] An electronic component package and a substrate on which the electronic component package is mounted, wherein the electronic component package includes a first metal foil, a second metal foil overlapping the first metal foil, and a joint portion where an outer edge portion of the first metal foil and an outer edge portion of the second metal foil are joined. 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 2 times or more the width dimension of the joint portion. Among the directions perpendicular to the main surface, when the direction in which the second metal foil is located with respect to the first metal foil is defined as the negative direction, the surface on the negative direction side of the joint portion is fixed to the substrate. When the maximum dimension in the direction perpendicular to the main surface is defined as the thickness dimension in a cross-sectional view taken along a cross-section perpendicular to the main surface, the thickness dimension of the joint portion is 90% or more of the entire range of the joint portion in the direction along the outer edge portion of the first metal foil and is larger than the sum of the thickness dimension of the first metal foil and the thickness dimension of the second metal foil. The shape of the joint portion is convex in the negative direction with respect to the outer surface of the second metal foil. An electronic component mounting substrate.

[0066] [8] A preparation step of preparing a first metal foil and a second metal foil overlapping the first metal foil, and a joining step of forming a joint portion by joining the outer edge portion of the first metal foil and the outer edge portion of the second metal foil. When the maximum dimension in the direction perpendicular to the main surface is defined as the thickness dimension in a cross-sectional view taken along a cross-section perpendicular to the main surface, in the joining step, when viewed in a direction perpendicular to the main surface, the length dimension of the joint portion in the direction along the outer edge portion of the first metal foil is 2 times or more the width dimension of the joint portion, and 90% or more of the entire range of the joint portion in the direction along the outer edge portion of the first metal foil. The joint portion is formed by welding the outer edge portion of the first metal foil and the outer edge portion of the second metal foil so that 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. A method for manufacturing an electronic component package.

Explanation of reference numerals

[0067] PD…Positive direction ND…Negative direction 10…Package for electronic components 11…First metal foil 12…Second metal foil 13…Joint MF…Main surface D1…Thickness dimension D2…Thickness dimension D3…Thickness dimension EB…Electronic component mounting substrate CB…Substrate

Claims

1. a first metal foil, a second metal foil overlapping the first metal foil, a joint portion which is a portion where an outer edge portion of the first metal foil and an outer edge portion of the second metal foil are joined, and comprising when viewed in a direction perpendicular to the main surface of the first metal foil, the length dimension of the joint portion in a direction along the outer edge portion of the first metal foil is 2 times or more the width dimension of the joint portion, when viewed in cross-section in a cross-section perpendicular to the main surface, when the maximum dimension in a direction perpendicular to the main surface is defined as the thickness dimension, in 90% or more of the entire range of the joint portion in a direction along the outer edge portion 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 a package for an electronic component.

2. in 90% or more of the entire range of the joint portion in a direction along the outer edge portion 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, the thickness dimension of the second metal foil, and 1 / 2 of the thickness dimension of the first metal foil or 1 / 2 of the thickness dimension of the second metal foil The package for an electronic component according to Claim 1.

3. The joint portion continuously extends over a range of 25% or more of the outer edge portion in a direction along the outer edge portion of the first metal foil The package for an electronic component according to Claim 1.

4. The joint portion continuously extends over the entire range of the outer edge portion in a direction along the outer edge portion of the first metal foil The package for an electronic component according to Claim 1.

5. Among the directions perpendicular to the main surface, when the direction in which the first metal foil is located with respect to the second metal foil is defined as the positive direction, when viewed in cross-section in a cross-section perpendicular to the main surface of the first metal foil, the shape of the joint portion is convex in the positive direction with respect to the main surface of the first metal foil, and the surface facing the positive direction in the joint portion is arc-shaped The package for an electronic component according to Claim 1.

6. when the direction opposite to the positive direction is defined as the negative direction, the shape of the joint portion is convex in the negative direction with respect to the outer surface of the second metal foil The package for an electronic component according to Claim 5.

7. comprising a package for an electronic component and a substrate on which the package for an electronic component is mounted, the package for an electronic component a first metal foil, a second metal foil overlapping the first metal foil, a joint portion which is a portion where an outer edge portion of the first metal foil and an outer edge portion of the second metal foil are joined, and comprising 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 not less than twice the width dimension of the joint portion. Among the directions perpendicular to the main surface, when the direction in which the second metal foil is located with respect to the first metal foil is defined as the negative direction. The surface on the negative direction side of the joint portion is fixed to the substrate. When the maximum dimension in the direction perpendicular to the main surface in a cross-sectional view taken along a cross-section perpendicular to the main surface is defined as the thickness dimension. The thickness dimension of the joint portion is not less than 90% of the entire range of the joint portion in the direction along the outer edge portion of the first metal foil and is greater than the sum of the thickness dimension of the first metal foil and the thickness dimension of the second metal foil. The shape of the joint portion is convex in the negative direction with respect to the outer surface of the second metal foil. Electronic component mounting substrate.

8. A preparation step of preparing a first metal foil and a second metal foil overlapping the first metal foil, A joining step of forming a joint portion 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 the direction perpendicular to the main surface in a cross-sectional view taken along a cross-section perpendicular to the main surface of the first metal foil is defined as the thickness dimension. In the joining step, When viewed in a direction perpendicular to the main surface, the length dimension of the joint portion in the direction along the outer edge portion of the first metal foil is not less than twice the width dimension of the joint portion. So that 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 not less than 90% of the entire range of the joint portion in the direction along the outer edge portion of the first metal foil. The joint portion is formed by welding the outer edge portion of the first metal foil and the outer edge portion of the second metal foil. Method for manufacturing an electronic component package.

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