Joint for electronic device and method for joining electronic components

Abstract

To suppress the occurrence of a short circuit between electrodes caused by lateral spread of solder when the electrodes of electronic components are joined together by soldering.SOLUTION: In a bonded body of electronic components in which a first electronic component 1 and a second electronic component 2 are integrally formed by joining a first electrode portion 11 and a second electrode portion 21 facing each other with a joining material 3, when viewed from a direction perpendicular to a surface 12a of the first electronic component 1 on which the first electrode portion 11 is formed and a surface 22a of the second electronic component 2 on which the second electrode portion 21 is formed, of the pair of the first electrode portion 11 and the second electrode portion 21 facing each other, one of the pairs is a small-area electrode portion in which the first electrode portion 11 is located inside the outer shape of the second electrode portion 21, and the other pair is a small-area electrode portion in which the second electrode portion 21 is located inside the outer shape of the first electrode portion 11. A pair in which the first electrode portion 11 is a small-area electrode portion and a pair in which the second electrode portion is a small-area electrode portion are arranged adjacent to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joint for electronic devices and a method for joining electronic components. [Background technology]

[0002] As semiconductor elements become more integrated and multifunctional over time, the number of terminals is increasing. Accordingly, the method of mounting semiconductor elements on wiring boards has changed from soldering using lead frames to a method called BGA (Ball Grid Array), in which electrodes (pins) are arranged in a grid pattern on the mounting surface of the semiconductor element and connected by solder, achieving an increase in pin count. In recent years, as integration density continues to increase, it has become necessary to further increase the number of terminals by making the electrodes of semiconductor elements smaller and narrowing the distance between the electrodes.

[0003] However, as the distance between electrodes of semiconductor elements becomes narrower, it has become necessary to consider the volume of solder used to connect the electrodes of electronic components such as semiconductor elements to the electrodes of a wiring board.This is because with conventional solder connections, there is a concern that the solder sandwiched between the wiring board and the electronic component will spread sideways, causing a short circuit between the electrodes.

[0004] To prevent the solder from spreading, a mounting method is used in which the electrodes that were underneath an insulating layer or non-conductor layer such as solder resist are made to protrude to form pillar electrodes, and the pillar electrodes on the wiring board and the pillar electrodes on the electronic component are connected with a small amount of solder to avoid short circuits between the electrodes.

[0005] This method can suppress lateral spreading by reducing the amount of solder, but if all the solder is alloyed, the mechanical properties of the solder may change significantly, and the tolerance for warping of the wiring board may decrease, resulting in cold joints and making it impossible to mount electronic components on the wiring board.

[0006] For this reason, for example, Patent Document 1 proposes a method in which the solder layer is formed by plating, thereby improving the variation in solder height that occurs with conventional solder printing methods and obtaining sufficient solder with a uniform thickness. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-140248 Summary of the Invention [Problem to be solved by the invention]

[0008] However, this method does not eliminate short circuits between electrodes that occur when the solder spreads laterally in areas where the distance between the electrodes is narrow. Furthermore, actual wiring boards have some warping, which means that the distance between the electrodes of the electronic component and the wiring board is narrow in some places and wide in others, so when attempting to connect the wide electrodes between the electronic component and the wiring board, the narrow electrodes are closer than the wide electrodes, resulting in a problem where the solder does not fit between the electrodes and spills out to the side.

[0009] The present invention has been made in view of the above circumstances, and aims to provide a joint for electronic devices and a method for joining electronic components that can suppress the occurrence of short circuits between electrodes that occur when solder is used to join electrodes of an electronic component such as a wiring board and a semiconductor element with solder, and that can prevent short circuits from occurring between electrodes that occur when solder spreads laterally. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a bonded body for an electronic device, which includes a plurality of first electrode portions formed on one surface of a first electronic component and a plurality of second electrode portions formed on one surface of a second electronic component and facing the respective first electrode portions, and in which the facing first electrode portions and second electrode portions are electrically connected via a bonding material, and when viewed from a direction perpendicular to the one surface of the first electronic component and the one surface of the second electronic component, among pairs of facing first electrode portions and second electrode portions, some pairs have small-area electrode portions in which the first electrode portions are located inside the outer shape of the second electrode portions, and other pairs have small-area electrode portions in which the second electrode portions are located inside the outer shape of the first electrode portions, and the some pairs in which the first electrode portions are small-area electrode portions are arranged adjacent to the other pairs in which the second electrode portions are small-area electrode portions. The small-area electrode portion is a protruding electrode protruding from one surface of the first electronic component or the second electronic component, and the first electrode portion or the second electrode portion that forms a pair with the small-area electrode portion is made of a layer electrode that is laminated on one surface of the first electronic component or the second electronic component and is thinner than the protruding electrode, and the protruding electrode is made of a base portion that is laminated on one surface and a protruding portion that protrudes from the upper surface of the base portion, and the layer electrode is made of a base portion that has the same thickness as the base portion of the protruding electrode. R 、 Joints for electronic devices is provided .

[0011] According to another aspect, there is provided a method for joining electronic components, which joins a first electronic component and a second electronic component by electrically joining a first electrode portion formed on a first electronic component and a second electrode portion formed on a second electronic component via a joining material, and when the first electrode portion and the second electrode portion are joined, some pairs of joined first and second electrode portions are small-area electrode portions in which the first electrode portion is located inside the outer shape of the second electrode portion when viewed from a direction perpendicular to one surface of the first electronic component and one surface of the second electronic component. The second electrode portion is a large-area electrode portion. The other pair is a small area electrode portion in which the second electrode portion is located inside the outer shape of the first electrode portion. and the first electrode portion is a large-area electrode portion. and the first electrode portions and the second electrode portions are arranged on one surface of the first electronic component and one surface of the second electronic component so that some pairs of the first electrode portions are small-area electrode portions and other pairs of the second electrode portions are adjacent to each other. The process of , Partial pair The first electrode is a small-area electrode. and a large-area electrode part The second electrode part are electrically connected via a bonding material. , other vs. to form The second electrode is a small-area electrode. and a large-area electrode part 1st electrode Department and are electrically joined via a joining material. the small-area electrode portion is a protruding electrode made up of a base portion and a protruding portion protruding from the upper surface of the base portion, and the large-area electrode portion is a layer electrode made up of a base portion having the same thickness as the base portion of the protruding electrode, and the arranging step includes, for each of the first electronic component and the second electronic component, a step of simultaneously forming base portions of the small-area electrode portion and the large-area electrode portion, which have the same thickness but different sizes, on one surface of the first electronic component or the second electronic component, and a step of forming the protruding portion on the upper surface of the base portion of the small-area electrode portion. A method for joining electronic components is provided. [Effects of the Invention]

[0012] According to one aspect of the present invention, it is possible to provide a bonded assembly for electronic devices in which electronic components are bonded together with solder, and a method for bonding electronic components, which does not cause short circuits between electrodes even when the distance between adjacent electrodes is narrow. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing an example of a bonded body for an electronic device according to an embodiment of the present invention. [Figure 2] 3 is a diagram illustrating an example of a surface of the first electronic component on which a first electrode portion is formed. FIG. [Figure 3] 10 is a diagram illustrating an example of a surface of a second electronic component on which a second electrode portion is formed. FIG. [Figure 4] FIG. 2 is a cross-sectional view of the first electronic component taken along the line AA. [Figure 5] 4 is an example of a process diagram illustrating a method for forming a first electrode portion. [Figure 6] 1A to 1C are explanatory views illustrating the operation of a bonded assembly for an electronic device according to an embodiment of the present invention. [Figure 7] 1A to 1C are explanatory views illustrating the operation of a bonded assembly for an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from the actual ones. Furthermore, the drawings also include parts whose dimensional relationships and ratios differ from each other.

[0015] Furthermore, the embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the arrangement of components to those shown below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims.

[0016] <Configuration> FIG. 1 is a cross-sectional view showing an example of a bonded body 100 for an electronic device according to one embodiment of the present invention (hereinafter also simply referred to as a bonded body). The bonded body 100 includes a first electronic component 1 and a second electronic component 2. In the bonded body 100, the first electronic component 1 and the second electronic component 2 are integrally formed by bonding a first electrode portion 11 of the first electronic component 1 to a second electrode portion 21 of the second electronic component 2 with a bonding material 3 made of solder. The first electronic component 1 is, for example, a semiconductor element, and the second electronic component 2 is, for example, a wiring board on which the semiconductor element is mounted.

[0017] Fig. 2 is a configuration diagram showing an example of a surface on which a first electrode portion 11 of a first electronic component 1 is formed, and Fig. 3 is a configuration diagram showing an example of a surface on which a second electrode portion 21 of a second electronic component 2 is formed. Fig. 4 is a cross-sectional view taken along line AA in Fig. 2, and Fig. 4 is also a cross-sectional view taken along line BB in Fig. 3.

[0018] As shown in FIG. 2, the first electronic component 1 has a plurality of first electrode portions 11 formed on one surface 12a of the component body 12. The first electrode portions 11 include small-area electrode portions 11A and large-area electrode portions 11B, which are elongated pillar-shaped (protruding) portions formed perpendicular to the surface 12a, and are arranged alternately at the intersections of a lattice. The small-area electrode portion 11A includes a thin, layered base portion a1 that is circular when viewed perpendicular to the surface 12a, and a protruding portion a2 that protrudes from the center of the base portion a1. The large-area electrode portion 11B includes a thin, layered base portion a11 that is circular when viewed perpendicular to the surface 12a. The base portions a1 and a11 have the same thickness.

[0019] 3, the second electronic component 2 has a plurality of second electrode portions 21 formed on one surface 22a of the component body 22. The second electrode portions 21 include a small-area electrode portion 21A having the same shape as the small-area electrode portion 11A, and a large-area electrode portion 21B having the same shape as the large-area electrode portion 11B. The small-area electrode portions 21A and the large-area electrode portions 21B are arranged alternately on the intersections of the lattice, and the second electrode portions 21 are arranged so that when the first electronic component 1 and the second electronic component 2 are joined, the small-area electrode portion 11A of the first electronic component 1 faces the large-area electrode portion 21B of the second electronic component 2, and the large-area electrode portion 11B of the first electronic component 1 faces the small-area electrode portion 21A of the second electronic component 2, and so that when viewed from a direction perpendicular to one surface 12a, 22a, the small-area electrode portion 11A of the first electronic component 1 is located inside the large-area electrode portion 21B of the second electronic component 2, and the small-area electrode portion 21A of the second electronic component 2 is located inside the large-area electrode portion 11B of the first electronic component 1.

[0020] The small-area electrode portions 11A, 21A and the large-area electrode portions 11B, 21B can be any size as long as adjacent electrode portions do not contact each other, but their sizes must be determined taking into consideration the resist resolution limit, exposure position accuracy, and plating conditions in the manufacturing process described below.

[0021] The small-area electrode portions 11A, 21A and the large-area electrode portions 11B, 21B are preferably made of copper or a copper-containing alloy. This is because they can be easily formed by plating when forming wiring. Furthermore, when solder is used as a bonding material (described later), an alloy is formed, which can improve connection reliability.

[0022] Furthermore, for the small-area electrode portions 11A, 21A and the large-area electrode portions 11B, 21B, it is possible to coat the surfaces of at least one of the electrode portions 11 or 21 of the first electronic component 1 and the second electronic component 2 with a bonding material 3 before mounting the first electronic component 1 on the second electronic component 2. In FIG. 4 , the bonding material 3 is provided on the tip portions of the small-area electrode portions 11A, 21A. The bonding material 3 can be solder made of tin or a tin alloy. Alternatively, the bonding material 3 can be a mixture containing a metal and an organic component. When using a tin alloy solder, it can be deposited by plating. Alternatively, by using a solder paste containing flux as the bonding material 3, the electrodes can be coated with solder by printing or dispensing. Although not shown, when coating the solder by solder printing or dispensing, a means for ensuring solder wettability, such as surface treatment of the electrode surface, can also be added.

[0023] Furthermore, when solder is coated as the bonding material 3, even if the heights of the pillar-shaped small area electrode portions 11A, 21A are uneven, the solder can absorb the height variations, and all of the first electrode portions 11 of the first electronic component 1 and all of the second electrode portions 21 of the second electronic component 2 can be bonded via the bonding material 3.

[0024] When joining the first electronic component 1 and the second electronic component 2, the solder as the joining material 3 that has been coated on the small-area electrode portions 11A, 21A is brought into contact with the large-area electrode portions 11B, 21B, and reflow is performed to electrically join the first electronic component 1 and the second electronic component 2.

[0025] 1 to 4 show only a portion of the bonded body 100, and the bonded body 100 may be continuous in the width and depth directions, or may be smaller. Furthermore, the component bodies 12 and 22 are not limited to the shapes shown in FIGS. 1 to 4, and may have any shape as long as they have electrode portions on the surfaces 12a and 22a on which the electrodes are formed.

[0026] <Manufacturing method> The first electronic component (for example, wiring board) 1 and the second electronic component (for example, semiconductor element) 2 have their inner layers manufactured according to a known manufacturing method for electronic components such as the first and second electronic components 1 and 2.

[0027] After the inner layers are formed, the first electrode portion 11 and the second electrode portion 21 are created on the component bodies 12, 22. Here, the case where the first electrode portion 11 is created on a wiring board as the first electronic component 1 is described, but the second electrode portion 21 can be created in the same way when created on the second electronic component 2. Furthermore, the method for creating the first electrode portion 11 and the second electrode portion 21 is not limited to the method described below.

[0028] 5(a), after forming the component body 12, a seed layer (not shown) for electrolytic plating is laminated on the electrode formation surface of the component body 12, then a plating resist 31 is laminated, and openings that will become the electrode portions 11 are formed by photolithography. Next, copper is deposited by electrolytic copper plating in the openings 32 between the resists 31 of the component body 12 to form the base portion a1 of the small-area electrode portion 11A and the base portion a11 of the large-area electrode portion 11B.

[0029] 5(b), the resist 31 is peeled off once, and a plating resist 33 is laminated again, and an opening is formed by photolithography to form an opening 34 for forming the protrusion a2 of the small-area electrode portion 11A. Electrolytic copper plating is again performed on this opening to form the protrusion a2 of the small-area electrode portion 11A.

[0030] Next, solder is deposited as the bonding material 3 on the protruding portion a2 by electrolytic tin plating. The bonding material 3 may be formed by filling solder paste, anisotropic conductive film, or metal paste, in addition to tin plating, and is not limited to these as long as it can obtain conductivity and can be fixed.

[0031] Finally, the resist 33 is peeled off, and the seed layer (not shown) provided for electrolytic plating is removed by etching or the like (FIG. 5(c)). As a result, T-pillar-shaped small-area electrode portions 11A and large-area electrode portions 11B made of thin layer electrodes are formed on the electrode formation surface 12a of the component body (substrate body) 12.

[0032] Although not shown here, it is also possible to laminate a solder resist as needed. Furthermore, instead of plating the bonding material 3, it is also possible to select a solder printing method or a method of mounting a solder ball. Furthermore, it is also possible to perform a surface treatment on the tip of the protruding portion a2 before providing the bonding material 3.

[0033] Through the above steps, first electrode portions 11 (11A, 11B) are formed on the wiring board as the first electronic component 1. Second electrode portions 21 (21A, 21B) are formed on the semiconductor element as the second electronic component 2 using a similar procedure.

[0034] Then, after the first electrode portion 11 and the second electrode portion 21 are formed in the first electronic component 1 and the second electronic component 2, respectively, a mounting process (bonding process) is performed in which the second electronic component (semiconductor element) 2 is mounted on the first electronic component (wiring board) 1.

[0035] This mounting step (bonding step) can use a known mounting method. A typical method involves aligning the first electrode portion 11 of the first electronic component 1 and the second electrode portion 21 of the second electronic component 2 using alignment marks so that the first electrode portion 11 faces the second electrode portion 21 of the second electronic component 2, and so that the small-area electrode portion 11A of the first electronic component 1 faces the large-area electrode portion 21B of the second electronic component 2. Heating is then performed while the first electrode portion 11 and the second electrode portion 21 are in contact with each other, melting the solder that forms the bonding material 3 and bonding the first electrode portion 11 and the second electrode portion 21 together.

[0036] As a result, as shown in FIG. 1, the small-area electrode portion 11A of the first electronic component 1 and the large-area electrode portion 21B of the second electronic component 2 are bonded together, and a mounting substrate is formed in which the large-area electrode portion 11B of the first electronic component 1 and the small-area electrode portion 21A of the second electronic component 2 are bonded together.

[0037] <Effects> As shown in FIG. 4 , in the bonded structure 100 according to this embodiment, the electrode portions adjacent to the small-area electrode portions 11A and 21A in the first electronic component 1 and the second electronic component 2 are the large-area electrode portions 11B and 21B. Therefore, even if solder overflows from the outer periphery of the small-area electrode portion 11A and 21A at the joint between the first electrode portion 11 of the first electronic component 1 and the second electrode portion 21 of the second electronic component 2, the solder will not overflow from the large-area electrode portions 11B and 21B. In other words, the large-area electrode portions 11B and 21B can absorb the lateral spread of solder that overflows at the joint between the first electronic component 1 and the second electronic component 2. Therefore, the first electrode portion 11 and the second electrode portion 21 can be bonded using a bonding material 3 sufficient for connection, thereby improving the reliability of the bonded structure 100.

[0038] 6, when the first electronic component 1 and the second electronic component 2 are joined, if misalignment occurs, the positions where the small-area electrode portions 11A and 21A face each other on the large-area electrode portions 11B and 21B will be misaligned, and the areas on the large-area electrode portions 11B and 21B that the solder contacts will be closer to their edges. However, when viewed from a direction perpendicular to the surface 12a, the small-area electrode portions 11A and 21A are located inside the large-area electrode portions 11B and 21B. Therefore, even if the solder overflows around the joint between the first electrode portion 11 and the second electrode portion 21, the solder can be prevented from overflowing to the outer periphery of the large-area electrode portions 11B and 21B. Therefore, it is possible to prevent short circuits between adjacent first electrode portions 11 and second electrode portions 21 via the solder.

[0039] As shown in FIG. 7, suppose a bonded assembly 200 for an electronic device includes a first electronic component 210 and a second electronic component 220, in which all first electrode portions 211 of the first electronic component 210 have the same shape and are formed from a circular base portion a211 when viewed from a direction perpendicular to a surface 212a on which the electrode portions of the component body 212 are formed and a protruding portion a212 protruding from the center of the base portion a211, and all second electrode portions 221 of the second electronic component 220 have the same shape and are formed from a circular base portion a221 when viewed from a direction perpendicular to a surface 222a on which the electrode portions of the component body 222 are formed. When the base portion a211 and the base portion a221 are aligned when viewed from a direction perpendicular to the faces 212a and 222a, if the first electrode portion 211 and the second electrode portion 221 are misaligned, the solder connecting them may protrude from the joint between the protrusion portion a212 of the first electrode portion 211 and the second electrode portion 221 at the joint between the first electrode portion 211 and the second electrode portion 221, and may protrude from the outer periphery of the second electrode portion 221, which may cause an inter-electrode short circuit via the solder between adjacent second electrode portions 221 in the second electronic component 220.

[0040] Therefore, it is necessary to set the distance between the second electrode portions 221 taking into consideration the amount of solder that protrudes from the second electrode portions 221, i.e., it is necessary to ensure a certain distance between the second electrode portions 221, and accordingly, it is necessary to ensure a certain distance between the first electrode portions 211. In other words, when taking into consideration the amount of solder that protrudes, it is necessary to arrange the electrodes so that the distance between adjacent electrodes is wider. Also, if the electrodes are made small to avoid short circuits between adjacent electrode portions, there is a possibility that they will not face each other if misalignment occurs.

[0041] In contrast, in the bonded body 100 of this embodiment, the adjacent electrode portions are small-area electrode portions 11A, 21A and large-area electrode portions 11B, 21B as shown in Fig. 4, so that the area of ​​one of the electrode portions can be increased while keeping the center-to-center distance of the electrode portions narrow. In other words, the distance between adjacent electrodes can be shortened while avoiding short circuits between the adjacent electrodes due to solder overflowing at the joint portion.

[0042] <Modification> (1) The first electronic component 1 and the second electronic component 2 are not limited to a combination of a semiconductor element and a wiring board. For example, they may be semiconductor elements or wiring boards, and there are no restrictions on the combination.

[0043] (2) In the above embodiment, a case has been described in which a T-shaped pillar is used as the small-area electrode portion 11A, 21A, but this is not a limitation and a straight pillar may also be used. Furthermore, the small-area electrode portion 11A, 21A is not limited to a cylinder, and may be a columnar shape such as a polygonal pillar, or may be a pyramidal shape such as a cone or a polygonal pyramid. Any shape is acceptable as long as the small-area electrode portion is located inside the paired large-area electrode portion when viewed from a direction perpendicular to the surface on which the small-area electrode portion 11A, 21A is formed and the surface on which the large-area electrode portion 11B, 21B is formed.

[0044] (3) In the above embodiment, the large-area electrode portions 11B, 21B are formed from thin layer electrodes, but this is not limited to this. They can also be formed from a two-tiered layer electrode having a thin first electrode layer and a second electrode layer stacked on the first electrode layer and having an outer shape smaller than that of the first electrode layer.

[0045] (4) In the above embodiment, the first electrode portion 11 and the second electrode portion 21 are arranged on the intersections of a grid, but this is not limited to this and they can be arranged at any position. In this case, it is sufficient to arrange the adjacent electrode portions so that they are a combination of small-area electrode portions 11A, 21A and large-area electrode portions 11B, 21B.

[0046] (5) In the above embodiment, the first electrode portions 11 of the first electronic component 1 are either small-area electrode portions 11A or large-area electrode portions 11B, and the second electrode portions 21 of the second electronic component 2 are either small-area electrode portions 21A or large-area electrode portions 21B. However, this is not limiting. When viewed in a direction perpendicular to the surface 12a of the first electronic component 1 and the surface 22a of the second electronic component 2, among pairs of opposing first electrode portions 11 and second electrode portions 21, it is sufficient that a pair in which the first electrode portion 11 is located inside the outer shape of the second electrode portion 21 and a pair in which the second electrode portion 21 is located inside the outer shape of the first electrode portion 11 are adjacent to each other.

[0047] Furthermore, for example, in the first electrode portions 11 and second electrode portions 21 arranged in a vertical and horizontal alignment, large area electrode portions and small area electrode portions may be arranged alternately in only one row or column, and the first electrode portions 11 and second electrode portions 21 in the other rows and columns may be formed to have the same shape, and it is sufficient that there is at least a pair (first pair) in which the first electrode portion 11 is located inside the outer shape of the second electrode portion 21, and a pair (second pair) in which the second electrode portion 21 is located inside the outer shape of the first electrode portion 11, and that these pairs have electrode portions arranged adjacent to each other.

[0048] (6) In the above embodiment, the first electrode portion 11 and the second electrode portion 21 are formed on the electrode formation surface 12a of the component body 12. However, this is not limiting. For example, the first electrode portion 11 and the second electrode portion 21 may be formed so that the upper surfaces of the base portions a1 of the small-area electrode portions 11A and 21A, the upper surfaces of the large-area electrode portions 11B and 21B, and the electrode formation surface of the component body 12 are flush with each other.

[0049] (7) In the above embodiment, the small-area electrode portions 11A and 21A and the large-area electrode portions 11B and 21B are described as having the same shape, but this is not limited to this. For example, the shape of the protrusion a2 may be different. In short, the small-area electrode portion may have a shape that positions it inside the large-area electrode portion that it pairs with when viewed from a direction perpendicular to the surface on which the small-area electrode portions 11A and 21A are formed and the surface on which the large-area electrode portions 11B and 21B are formed.

[0050] (8) In the above embodiment, the bonding material 3 is provided at the tip of the small-area electrode portions 11A, 21A. However, instead of the small-area electrode portions 11A, 21A, the bonding material 3 may be provided on the portion of the large-area electrode portions 11B, 21B that faces the small-area electrode portions 11A, 21A, or may be provided on both the small-area electrode portion 11A, 21A side and the large-area electrode portion 11B, 21B side.

[0051] The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment. Various modifications can be made depending on the design, etc., even in forms other than this embodiment, as long as they do not deviate from the technical idea of ​​the present invention. [Explanation of symbols]

[0052] 1. First Electronic Components 2 Secondary Electronic Components 3 Bonding material 11 First electrode part 21 Second electrode part 11A, 21A small area electrode section 11B, 21B Large area electrode section

Claims

1. A bonded assembly for an electronic device includes a plurality of first electrode portions formed on one surface of a first electronic component, and a plurality of second electrode portions formed on one surface of a second electronic component, the first electrode portions and the second electrode portions facing each other, the first electrode portions and the second electrode portions facing each other being electrically connected via a bonding material, When viewed from a direction perpendicular to the one surface of the first electronic component and the one surface of the second electronic component, among the pairs of the opposing first electrode portion and the second electrode portion, in some pairs, the first electrode portion is a small-area electrode portion located inside an outer shape of the second electrode portion, and in other pairs, the second electrode portion is the small-area electrode portion located inside an outer shape of the first electrode portion, and the some pairs in which the first electrode portion is the small-area electrode portion and the other pairs in which the second electrode portion is the small-area electrode portion are arranged adjacent to each other, the small-area electrode portion is a protruding electrode protruding from the one surface of the first electronic component or the second electronic component, and the first electrode portion or the second electrode portion that forms a pair with the small-area electrode portion is made of a layer electrode that is laminated on the one surface of the first electronic component or the second electronic component and is thinner than the protruding electrode, the protruding electrode includes a base portion laminated on the one surface and a protruding portion protruding from an upper surface of the base portion, A bonded assembly for electronic devices, wherein the layer electrode comprises a base portion having the same thickness as the base portion of the protruding electrode.

2. 2. The joined body for electronic equipment according to claim 1, wherein the first electrode portion and the second electrode portion are aligned lengthwise and widthwise.

3. 3. The joined body for electronic equipment according to claim 1, wherein the joining material is solder.

4. 4. The bonded assembly for electronic equipment according to claim 1, wherein the first electronic component is a semiconductor element, and the second electronic component is a wiring board.

5. A method for joining electronic components, comprising: electrically joining a first electrode portion formed on a first electronic component and a second electrode portion formed on a second electronic component via a joining material, thereby joining the first electronic component and the second electronic component, a step of arranging the first electrode portion and the second electrode portion on one surface of the first electronic component and one surface of the second electronic component so that, when the first electrode portion and the second electrode portion are joined together, when viewed from a direction perpendicular to the one surface of the first electronic component and the one surface of the second electronic component, some of the joined pairs of the first electrode portion and the second electrode portion have the first electrode portion as a small-area electrode portion located inside an outer shape of the second electrode portion and the second electrode portion as a large-area electrode portion, and other pairs have the second electrode portion as a small-area electrode portion located inside an outer shape of the first electrode portion and the first electrode portion as a large-area electrode portion, and the some pairs in which the first electrode portion is the small-area electrode portion are adjacent to the other pairs in which the second electrode portion is the small-area electrode portion; a step of electrically joining the first electrode portion, which is the small-area electrode portion, and the second electrode portion, which is the large-area electrode portion, forming one of the pairs via a bonding material, and electrically joining the second electrode portion, which is the small-area electrode portion, and the first electrode portion, which is the large-area electrode portion, forming another of the pairs via a bonding material, the small-area electrode portion is a protruding electrode having a base portion and a protruding portion protruding from an upper surface of the base portion, and the large-area electrode portion is a layer electrode having a base portion having the same thickness as the base portion of the protruding electrode, The placing step includes: a step of simultaneously forming the base portions of the small-area electrode portion and the large-area electrode portion, each having the same thickness but different sizes, on the one surface of the first electronic component or the second electronic component, for each of the first electronic component and the second electronic component; forming the protrusion on the upper surface of the base portion of the small area electrode portion; A method for joining electronic components, comprising:

6. The step of simultaneously forming the base portion includes: a step of laminating a plating resist for forming the base portion on the one surface of each of the first electronic component and the second electronic component, and forming an opening for forming the base portion of the small-area electrode portion in the plating resist, and an opening wider than the opening for forming the base portion of the small-area electrode portion, as an opening for forming the base portion of the large-area electrode portion; depositing copper as a conductor in the openings for forming the base portions of the small-area electrode portion and the large-area electrode portion to form the base portions of the small-area electrode portion and the large-area electrode portion, The step of forming the protrusion portion includes: a step of peeling off the plating resist for forming the base portion, and then laminating a plating resist for forming the protrusion portion on the one surface so as to cover the base portion, and forming an opening for forming the protrusion portion in the plating resist at a position that overlaps the base portion of the small area electrode portion when viewed from a direction perpendicular to the one surface; forming the protrusions by depositing copper as a conductor in the protrusion-forming openings; a step of removing the plating resist for forming the protrusion portion; 6. The method for joining electronic components according to claim 5, further comprising:

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