Semiconductor device

Abstract

To provide a semiconductor device in which the generation of Kirkendall void is suppressed and the reliability is improved.SOLUTION: A semiconductor device in an embodiment has: a first conductive member; a first conductive film provided on a part of the first conductive member and including a metal element whose diffusion coefficient is smaller than that of the first conductive member; a first solder material covering the first conductive film; a semiconductor element provided on the first solder material; a second solder material provided on the semiconductor element; a second conductive member having a first region facing the semiconductor element through the second solder material; a resin part for sealing the first conductive member, the second conductive member, the first conductive film, the first solder material, the second solder material, and the semiconductor element; and a first peripheral region located in the periphery of a region of the first conductive member that overlaps with the semiconductor element and coming in direct contact with the resin part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] FIELD An embodiment of the present invention relates to a semiconductor device. [Background technology]

[0002] A semiconductor element and a conductive member such as a die pad are sometimes joined using solder. For example, when the solder is a metal containing Sn and the die pad is a metal containing Cu, Kirkendall voids may occur in the die pad due to interdiffusion between different metal elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-082694 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a semiconductor device which suppresses the occurrence of Kirkendall voids and has improved reliability. [Means for solving the problem]

[0005] A semiconductor device according to an embodiment includes a first conductive member, a first conductive film provided on a portion of the first conductive member and containing a metal element having a smaller diffusion coefficient than the first conductive member, a first solder material that covers the first conductive film, a semiconductor element provided on the first solder material, a second solder material provided on the semiconductor element, a second conductive member having a first region that faces the semiconductor element via the second solder material, a resin portion that seals the first conductive member, the second conductive member, the first conductive film, the first solder material, the second solder material, and the semiconductor element, and a first peripheral region of the first conductive member that is located around the region where the semiconductor element overlaps and that is in direct contact with the resin portion.

[0006] A semiconductor device according to another embodiment includes a first conductive member, a first conductive film provided on a portion of the first conductive member and containing a metal element having a smaller diffusion coefficient than the first conductive member, a first solder material provided on the first conductive film, a semiconductor element provided on the first solder material, a second solder material provided on the semiconductor element, a second conductive member having a first region facing the semiconductor element via the second solder material, a resin portion that seals the first conductive member, the second conductive member, the first conductive film, the first solder material, the second solder material, and the semiconductor element, and a first peripheral region of the first conductive member located around a region where the semiconductor element overlaps and in direct contact with at least a portion of the resin portion. The first conductive member has a first exposed portion exposed from the resin portion, and the first peripheral region and the resin portion are in direct contact with each other in a portion of the first peripheral region near the first exposed portion. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view of a semiconductor device 101 according to a first embodiment. [Diagram 2] 1 is a perspective view showing an internal wiring structure of a semiconductor device 101 according to a first embodiment. [Diagram 3] 3 is a cross-sectional view taken along the line AA′ shown in FIG. 2. [Figure 4A] 2 is a top view showing the positional relationship between a first conductive film 21 and a first solder material 31. FIG. [Figure 4B] 2 is a top view showing the positional relationship between a first conductive film 21 and a first solder material 31. FIG. [Figure 4C] 2 is a top view showing the positional relationship between a first conductive film 21 and a first solder material 31. FIG. [Diagram 5] 1 is a cross-sectional view of a semiconductor device 102 according to a second embodiment. [Figure 6] 2 is a top view showing the positional relationship between a first conductive film 21 and a first solder material 31. FIG. [Figure 7] 11 is a cross-sectional view of a semiconductor device 103 according to a third embodiment. FIG. [Figure 8]FIG. 11 is a cross-sectional view of a semiconductor device 104 according to a fourth embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a semiconductor device 105 according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0009] The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing.

[0010] For example, in the cross-sectional views shown in the present specification, some laminated structures are shown, but the thickness ratio of each layer of the laminated structure is not necessarily the same as that in reality. Even if one layer is shown thicker than the other layer in the cross-sectional view, in reality, the thickness of one layer and the other layer may be approximately the same, or one layer may be thinner than the other layer. In other words, the dimensions such as thickness shown in the drawings in the present specification may differ from the actual dimensions.

[0011] The direction from the first conductive member 11 to the semiconductor element 40 is defined as the Z direction (first direction). The direction perpendicular to the Z direction is defined as the X direction (second direction), and the direction intersecting the X and Z directions is defined as the Y direction (third direction). The semiconductor device 101 shown in Fig. 3 is shown in a cross-sectional view in the XZ plane. Note that, although the X direction, Y direction, and Z direction are shown in an orthogonal relationship in this embodiment, they may intersect with each other without being limited to being orthogonal.

[0012] For the sake of explanation, the positive direction in the Z direction is referred to as "up" and the negative direction in the Z direction is referred to as "down." However, the "up" and "down" directions are not limited to the direction of gravity or the directions when the semiconductor device is mounted.

[0013] In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed descriptions thereof will be omitted as appropriate.

[0014] (First embodiment) 1 and 2 show perspective views of a semiconductor device 101 according to a first embodiment. FIG. 1 shows the external appearance including a resin part 50, and FIG. 2 shows an example of an internal wiring structure. As shown in FIG. 1, a first conductive member 11 and a second conductive member 12 of the semiconductor device 101 partially protrude from the resin part 50. The first conductive member 11 is, for example, a lead frame. A plurality of parts of each of the first conductive member 11 and the second conductive member 12 may be exposed from the resin part 50. Note that the term "exposed" includes the case where they protrude as shown in FIG. 1 and FIG. 2, and the case where they are exposed on the bottom surface of the package.

[0015] 2 shows the internal wiring structure sealed in the resin part 50 in FIG. 1. The semiconductor element 40 is provided between the first conductive member 11 and the second conductive member 12. The region of the second conductive member 12 that faces the semiconductor element 40 in the Z direction is called the first region 12a. The semiconductor element 40 is sealed in the resin part 50. The first conductive member 11 and the second conductive member 12 are each electrically connected to the semiconductor element 40. A portion of the first conductive member 11 and the second conductive member 12 is sealed in the resin part 50.

[0016] For example, a MOSFET is formed in the semiconductor element 40. The first conductive member 11 is connected to, for example, a drain electrode of the semiconductor element 40, and the second conductive member 12 is connected to, for example, a source electrode. The semiconductor device 101 may further include a third conductive member 13. The third conductive member 13 is electrically connected to, for example, a gate electrode of the MOSFET. The third conductive member 13 is not limited to being a plate-shaped member as shown in FIG. 2. The third conductive member 13 may include, for example, a bonding wire.

[0017] The first conductive member 11 has first exposed portions 11p protruding from the resin part 50. Although the first exposed portions 11p are provided in four places in FIG. 2, they do not necessarily have to be provided in four places. Moreover, the second conductive member 12 has second exposed portions 12p protruding from the resin part 50. Although the second exposed portions 12p are provided in three places in FIG. 2, they do not necessarily have to be provided in three places.

[0018] The shapes of the first exposed portion 11p and the second exposed portion 12p are not limited to the shape shown in FIG. 2. For example, they may be gull-wing type or J-shaped. The gull-wing type is a shape having steps at different positions in the Z direction. A step is provided in the negative direction of the Z direction toward the tip of the first exposed portion 11p or the second exposed portion 12p. The J-shape is a shape in which the first exposed portion 11p is bent in the XZ plane and the tip of the first exposed portion 11p faces the positive direction of the X direction. In addition, the first exposed portion 11p and the second exposed portion 12p do not need to protrude from the resin portion 50 in the X direction, and may be electrically connected to the outside on the lower surface of the resin portion 50.

[0019] Fig. 3 shows the A-A' cross section shown in Fig. 2. The A-A' cross section is a cross section passing through the first exposed portion 11p of the first conductive member 11 and the second exposed portion 12p of the second conductive member 12 shown in Fig. 2.

[0020] A first conductive film 21, a first solder material 31, a semiconductor element 40, and a second solder material 32 are provided between the first conductive member 11 and the second conductive member 12. The first conductive film 21 is provided on a portion of the first conductive member 11. The first solder material 31 is provided on the first conductive film 21, and is in contact with a portion of the first conductive member 11 and at least a portion of the first conductive film 21. The semiconductor element 40 is provided on the first solder material 31.

[0021] The first conductive film 21 is not provided on the first exposed portion 11p of the first conductive member 11. It is preferable that the first conductive film 21 is covered with the first solder material 31 and is not in contact with the resin portion 50, because this improves the adhesion of the resin portion 50, as described below.

[0022] The second conductive member 12 has a first region 12a that faces the semiconductor element 40 in the Z direction. A second solder material 32 is provided between the semiconductor element 40 and the first region 12a of the second conductive member 12. The first region 12a and the semiconductor element 40 face each other via the second solder material 32 and are electrically connected to each other.

[0023] The first conductive member 11 and the second conductive member 12 are made of a metal containing, for example, Cu. The first conductive member 11 and the second conductive member 12 may be made of the same material.

[0024] The first conductive film 21 is a metal containing, for example, Ni. The first conductive film 21 functions as a barrier metal at the bonding surface between the first conductive member 11 and the first solder material 31. The first conductive film 21 contains a metal element having a smaller diffusion coefficient than the first conductive member 11. Here, a smaller diffusion coefficient means that migration of metal atoms is less likely to occur at the bonding surface with a dissimilar metal.

[0025] The first solder material 31 and the second solder material 32 are solders containing, for example, Sn. The first solder material 31 and the second solder material 32 are formed, for example, from the same material. The first solder material 31 and the second solder material 32 may contain Sn, for example, at a mass percent concentration of 50% or more. In addition to Sn, the first solder material 31 may contain at least one of Pb, Sb, Ni, Ag, Bi, Cu, and Zn.

[0026] The resin portion 50 seals the first conductive film 21, the first solder material 31, the semiconductor element 40, the second solder material 32, a portion of the first conductive member 11, and a portion of the second conductive member 12. The resin portion 50 contains, for example, an epoxy resin.

[0027] The first conductive member 11 has a first peripheral region 11r located around the region where the semiconductor element 40 overlaps. Here, the region where the semiconductor element 40 overlaps is a region of the first conductive member 11 where the shadow of the semiconductor element 40 extends when the semiconductor element 40 is projected in one direction (for example, the Z direction). Explaining with reference to FIG. 3, the first peripheral region 11r is a part of the upper surface of the first conductive member 11, and is located so as to surround the region where the first conductive member 11 and the first solder material 31 or the first conductive film 21 contact each other. The first conductive member 11 directly contacts the resin part 50 in at least a part of the first peripheral region 11r.

[0028] The first exposed portion 11p and the second exposed portion 12p are exposed from the resin portion 50. The first exposed portion 11p and the second exposed portion 12p are provided for electrical connection to an external electrode. For example, by applying a voltage between the first exposed portion 11p and the second exposed portion 12p, a current can be caused to flow from the first conductive member 11 through the semiconductor element 40 to the second conductive member 12.

[0029] The first peripheral region 11r does not include the first exposed portion 11p that is exposed from the resin portion 50.

[0030] The cross-sectional view of the semiconductor device 101 according to the first embodiment has been described above with reference to FIG.

[0031] Next, an example of the positional relationship between the first conductive film 21 and the first solder material 31 in the semiconductor device 101 according to the first embodiment will be described with reference to Fig. 4. Figs. 4A, 4B, and 4C are XY plan views showing the first conductive member 11 and the first conductive film 21.

[0032] 4, the resin portion 50 is located in the area surrounded by the dashed line. The first solder material 31 is located in the area surrounded by the dotted line. The hatching of the resin portion 50 and the first solder material 31 is omitted.

[0033] The first exposed portions 11p are exposed from the resin portion 50. FIG. 4 shows an example in which four first exposed portions 11p are provided, but the present invention is not limited to this example. The first solder material 31 and the semiconductor element 40 on the first solder material 31 may have the same outer shape, for example. In other words, the region surrounded by the dotted line may be interpreted as the region where the first solder material 31 is located, or may be interpreted as the region where the semiconductor element 40 is located.

[0034] The first peripheral region 11r of the first conductive member 11 is a region located around the region overlapping the semiconductor element 40. The first peripheral region 11r is located around the semiconductor element 40 in the positive and negative X directions and in the positive and negative Y directions. In Fig. 4, the first peripheral region 11r is shown as a region of the first conductive member 11 that is outside the region indicated by the dotted line (the region where the semiconductor element 40 is provided) and does not include the first exposed portion 11p.

[0035] The shape of the first conductive film 21 can be determined by the arrangement of the electrodes of the semiconductor element 40 provided on the first solder material 31. For example, it is desirable to arrange the first conductive film 21 so that it is located at a position overlapping with the electrodes when viewed from the Z direction, since this can suppress the occurrence of Kirkendall voids in the portion where the current mainly flows.

[0036] First, a description will be given with reference to FIG. 4A. The first conductive film 21 is covered with the first solder material 31 in the XY plane. Therefore, the resin part 50 does not contact the first conductive film 21. At least the first solder material 31 is interposed between the resin part 50 and the first conductive film 21. In other words, the outer shape of the first conductive film 21 in the XY plane is smaller than the outer shape of the first solder material 31 (semiconductor element 40). In this case, a part of the first solder material 31 directly contacts the first conductive member 11.

[0037] 4A, the first conductive film 21 does not directly contact the resin portion 50. The first peripheral region 11r directly contacts the resin portion 50. In particular, a region of the first peripheral region 11r located near the first exposed portion 11p directly contacts the resin portion 50. In other words, the first peripheral region 11r, which contacts the resin portion 50, is located between the first conductive film 21 and the first exposed portion 11p.

[0038] 4B shows a case where the shape of first conductive film 21 is not square and has no corners. In a shape having corners, there is a risk that stress will concentrate on a portion with a large curvature (small radius of curvature) of the interface between first conductive film 21 and first solder material 31. By providing first conductive film 21 in a shape without corners, for example, an oval or elliptical shape, it is possible to alleviate the stress.

[0039] 4C, the first conductive film 21 may be divided into a plurality of parts. Although Fig. 4C shows a case where the first conductive film 21 is divided into two rows in the X direction and the Y direction, the first conductive film 21 may be divided into more parts, or may be divided into different numbers in the X direction and the Y direction.

[0040] 4A, 4B, and 4C, the area where the first conductive film 21 is provided may be, for example, 20-90% of the area of ​​the area where the first solder material 31 is provided (the area surrounded by the dotted line), or may be 30-80%.

[0041] In the semiconductor device 101 according to this embodiment, the first conductive film 21 is provided on a portion of the first conductive member 11 and is interposed between the first conductive member 11 and the first solder material 31, thereby suppressing the occurrence of Kirkendall voids in the first conductive member 11 and suppressing deterioration of the characteristics of the semiconductor device. Furthermore, the first conductive member 11 can be in close contact with the resin part 50 in the first peripheral region 11r, improving the adhesion of the resin part 50 and improving the reliability of the semiconductor device.

[0042] According to the semiconductor device 101 of this embodiment, it is possible to suppress the occurrence of Kirkendall voids. For the sake of explanation, an example will be described below in which the first conductive member 11 contains Cu, the first conductive film 21 contains Ni, and the first solder material 31 contains Sn.

[0043] First, let us consider a case where the first conductive film 21 is not provided. That is, the first conductive member 11 containing Cu and the first solder material 31 containing Sn are in contact with each other. At the interface where the metal containing Cu and the metal containing Sn are joined, an alloy containing Cu and Sn is formed. The diffusion speeds of Cu atoms and Sn atoms are different at the interface, and Cu atoms diffuse faster than Sn atoms (the diffusion coefficient is large). As a result, the amount of Cu atoms diffusing from the first conductive member 11 to the first solder material 31 is greater than the amount of Sn atoms diffusing in the opposite direction. As described above, the effect of mutual diffusion at the interface where different metals are joined is called the Kirkendall effect.

[0044] Due to the difference in diffusion coefficient between Cu and Sn, Cu atoms are lost from the first conductive member 11 containing Cu or from the alloy region formed at the interface, resulting in the generation of vacancies. The vacancies generated by the Kirkendall effect are called Kirkendall voids.

[0045] That is, when the first conductive member 11 containing Cu comes into contact with the first solder material 31 containing Sn, Kirkendall voids may occur in the first conductive member 11. The occurrence of Kirkendall voids may deteriorate the conductivity of the first conductive member 11, and may increase the on-voltage of the semiconductor element 40.

[0046] On the other hand, consider a case where the first conductive film 21 containing Ni is provided as in the semiconductor device 101 according to this embodiment. Ni has a smaller diffusion coefficient than Cu. Therefore, the first conductive film 21 containing Ni can suppress the diffusion of atoms from the first conductive member 11 to the first solder material 31. Kirkendall voids in the first conductive member 11 can be suppressed.

[0047] By providing first conductive film 21 at least partially between first conductive member 11 and first solder material 31, Kirkendall voids can be suppressed, and deterioration of the characteristics of the semiconductor device can be suppressed.

[0048] Furthermore, according to the semiconductor device 101 of this embodiment, it is possible to improve the adhesion of the resin part 50. For the sake of explanation, an example will be described below in which the first conductive member 11 contains Cu and the first conductive film 21 contains Ni. The resin part 50 contains, for example, an epoxy resin. It is known that the adhesion between Cu and epoxy resin is superior to the adhesion between Ni and epoxy resin.

[0049] Unlike the present embodiment, when the first conductive film 21 is formed on the entire upper surface of the first conductive member 11 and is also provided on the first peripheral region and the first exposed portion 11p, the adhesion of the resin portion 50 decreases. This is because the first conductive film 21 is also formed on the first peripheral region 11r, and the first conductive film 21 and the resin portion 50 are in direct contact with each other. The first conductive film 21 containing Ni has lower adhesion to the resin portion 50 containing epoxy resin than the first conductive member 11 containing Cu, which increases the risk of resin peeling, thereby reducing the reliability of the semiconductor device.

[0050] Peeling (cracks) occurring between the first conductive film 21 and the resin part 50 on the first peripheral region 11r may reach the first solder material 31 or the semiconductor element 40 from the vicinity of the first exposed part 11p. There is a risk that moisture or the like may penetrate from the outside through the cracks, deteriorating the performance of the semiconductor device. As described above, when the first conductive film 21 is provided on the entire upper surface of the first conductive member 11, cracks may occur in the resin part 50, compromising the reliability of the semiconductor device.

[0051] 3, the first conductive film 21 is not provided at least in the vicinity of the first exposed portion 11p in the first peripheral region 11r, so that the first conductive member 11 contacts the resin portion 50 in at least a part of the first peripheral region 11r. The first conductive member 11 containing Cu has stronger adhesion to the resin portion 50 than the first conductive film 21 containing Ni, so there is less risk of the resin peeling off in the first peripheral region 11r.

[0052] 4A, the first conductive film 21 is covered with, for example, the first solder material 31. In other words, the first conductive film 21 does not contact the resin part 50. By covering the first conductive film 21 with the first solder material 31, it is possible to suppress a decrease in adhesion caused by contact between the first conductive film 21 and the resin part 50. In order to increase the adhesion of the resin part 50, it is desirable for the first conductive film 21 to be covered with the first solder material 31.

[0053] According to the semiconductor device 101 of this embodiment, the resin portion 50 and the first conductive member 11 are in contact with each other in the first peripheral region 11r, thereby suppressing peeling of the resin in the first peripheral region 11r and improving the reliability of the semiconductor device. In order to improve the adhesion of the resin portion 50, it is desirable that the first conductive film 21 is covered with the first solder material 31.

[0054] In addition, when the first conductive film 21 is covered with the first solder material 31, it is possible to more reliably improve the adhesion of the resin part 50. For example, when the first conductive film 21 is formed as shown in Fig. 4A, even if a positional deviation occurs when the first solder material 31 and the semiconductor element 40 are provided, the first conductive film 21 does not protrude from the first solder material 31 as long as the degree of the positional deviation is equal to or less than a predetermined value. When the first conductive film 21 is formed to have the same size as the outer shape of the first conductive member 11 or the semiconductor element 40, there is a risk that the first conductive film 21 will protrude from the first solder material 31 if a positional deviation occurs.

[0055] According to the semiconductor device 101 of this embodiment, it is possible to suppress Kirkendall voids and suppress deterioration of the characteristics of the semiconductor device by forming the first conductive film 21 at least partially between the first conductive member 11 and the first solder material 31. Furthermore, by not forming the first conductive film 21 in at least a part of the first peripheral region 11r, it is possible to suppress peeling of the resin part 50 and improve the reliability of the semiconductor device.

[0056] Second embodiment Fig. 5 is an AA' cross-sectional view of a semiconductor device 102 according to the second embodiment. In the following, when referring to an AA' cross-sectional view, it is intended to mean a cross-sectional view at a position corresponding to the AA' line in Fig. 2 according to the first embodiment in each embodiment. Fig. 6 is a plan view showing the arrangement of a first conductive film 21 in the second embodiment. Some descriptions of parts common to the semiconductor device 101 according to the first embodiment will be omitted.

[0057] First, the cross-sectional structure will be described with reference to Fig. 5. As shown in Fig. 5, the first conductive film 21 is provided on a portion of the first conductive member 11. The first solder material 31 is provided on the first conductive film 21. In other words, the first conductive film 21 is provided between the first solder material 31 and the first conductive member 11, and the first solder material 31 and the first conductive member 11 are not in direct contact with each other.

[0058] A portion of the first conductive film 21 contacts the resin portion 50. At least a portion of the first peripheral region 11r of the first conductive member 11 directly contacts the resin portion 50. The first conductive film 21 protruding from the first solder material 31 is provided in a portion of the first peripheral region 11r. In a portion of the first peripheral region 11r, the first conductive member 11 and the resin portion 50 face each other with the first conductive film 21 interposed therebetween.

[0059] On the other hand, in the first peripheral region 11r, the first conductive film 21 is not provided in the vicinity of the first exposed portion 11p. In other words, the first exposed portion 11p and the first conductive film 21 are separated from each other, and the first peripheral region 11r in contact with the resin portion 50 is provided between the first exposed portion 11p and the first conductive film 21.

[0060] Next, the positional relationship between the first conductive film 21 and the first solder material 31 will be described with reference to FIG. 6. The configuration of FIG. 6 is the same as the configuration of FIGS. 4A, B, and C except for the shape of the first conductive film 21. For example, in FIG. 6, the resin part 50 is located in the area surrounded by the dashed line. The first solder material 31 is located in the area surrounded by the dotted line. It can also be understood that the area surrounded by the dotted line indicates the semiconductor element 40 provided on the first solder material 31. Hatching of the resin part 50 and the first solder material 31 is omitted.

[0061] The first solder material 31 is formed on the first conductive film 21. The area where the first solder material 31 is provided is smaller than the area where the first conductive film 21 is provided. The first conductive film 21 is interposed between the first solder material 31 and the first conductive member 11.

[0062] The first peripheral region 11r of the first conductive member 11 is a periphery of the region where the semiconductor element 40 overlaps, and is located in the positive and negative X-direction and the positive and negative Y-direction. The first conductive film 21 is provided in at least a portion of the first peripheral region 11r in the positive and negative X-direction and the positive and negative Y-direction. However, the first conductive film 21 is separated from the first exposed portion 11p.

[0063] In other words, as long as the first conductive film 21 does not reach the first exposed portion 11p, the first conductive film 21 can be formed with a large area protruding from the first solder material 31. In the positive X direction and the positive and negative Y directions of the first conductive member, the first conductive film 21 may be formed larger than the case shown in FIG.

[0064] For example, the first conductive film 21 may be formed on the entire surface of the first peripheral region 11r except for the vicinity of the first exposed portion 11p. That is, the first conductive film 21 is formed by, for example, a plating process, but the mask for the plating process can be limited to the vicinity of the first exposed portion 11p in the first peripheral region 11r. In other words, the mask for the plating process only needs to cover at least the first exposed portion 11p. There is no need to form a mask in the region located in the positive direction in the X direction from a predetermined position between the first exposed portion 11p and the semiconductor element 40 in the X direction, which makes it easier to form the mask.

[0065] According to the semiconductor device 102 of the second embodiment, while the first conductive film 21 is provided over a larger area than the semiconductor device 101 of the first embodiment, resin peeling is suppressed in the vicinity of the first exposed portion 11p in the first peripheral region 11r, and the reliability of the semiconductor device can be improved. Moreover, compared to the semiconductor device 101 of the first embodiment, the occurrence of Kirkendall voids can be further suppressed, and therefore deterioration of the characteristics of the semiconductor device can be suppressed.

[0066] In the semiconductor device 102 shown in FIG. 5, the first conductive film 21 is provided wider than that of the semiconductor device 101 according to the first embodiment, but the first conductive film 21 is not formed in the vicinity of the first exposed portion 11p in the first peripheral region 11r. In other words, the first conductive film 21 and the resin portion 50 are in contact with each other in the region of the first peripheral region 11r that is close to the semiconductor element 40, and even if resin peeling occurs, it is possible to suppress the growth of a crack that reaches the first exposed portion 11p. This is because the first peripheral region 11r and the resin portion 50 are in direct contact with each other in the vicinity of the first exposed portion 11p in the first peripheral region 11r, and have high adhesion. Resin peeling is suppressed in the vicinity of the first exposed portion 11p in the first peripheral region 11r, and moisture and the like are suppressed from entering the inside of the resin portion 50 from the outside.

[0067] 6, by forming the first conductive film 21 with an area larger than the first solder material 31, it is possible to reliably prevent the first conductive member 11 from coming into contact with the first solder material 31. Even if the first solder material 31 or the semiconductor element 40 is misaligned, the first conductive film 21 being provided widely can prevent the first solder material 31 from coming into contact with the first conductive member 11.

[0068] That is, in this embodiment, instead of allowing partial contact between the first conductive film 21 and the resin part 50, the first conductive film 21 can be more reliably formed between the first conductive member 11 and the first solder material 31. The first conductive film 21 can suppress the occurrence of Kirkendall voids, so that deterioration of the characteristics of the semiconductor device can be further suppressed compared to the first embodiment.

[0069] Third embodiment 7 is a cross-sectional view of a semiconductor device 103 according to a third embodiment. Description of some of the common parts with the semiconductor device 101 according to the first embodiment will be omitted.

[0070] The second conductive film 22 is provided at least partially between the second solder material 32 and the first region 12a of the second conductive member 12. The second conductive film 22 is covered with the second solder material 32. In other words, the second conductive film 22 is not in contact with the resin portion 50.

[0071] The second conductive film 22 contains a metal element having a smaller diffusion coefficient than the metal element constituting the first region 12a of the second conductive member 12. The second solder material 32 is, for example, a solder containing Sn. The second conductive film 22 is, for example, a metal containing Ni. The first region 12a of the second conductive member 12 is, for example, a metal containing Cu.

[0072] The second conductive film 22 is, for example, a film of a metal containing Ni provided at least partially between a metal containing Sn and a metal containing Cu. The second conductive film 22 functions as a barrier metal that suppresses the Kirkendall effect that occurs between a metal containing Sn and a metal containing Cu.

[0073] As for the shape of the second conductive film 22, similarly to the case described with reference to Figures 4A, 4B, and 4C, the shape may be various, such as a square or an oval, and may be divided into multiple parts.

[0074] According to the semiconductor device 103 of this embodiment, the second conductive film 22 is provided at least partially between the second solder material 32 and the first region 12a, thereby suppressing the Kirkendall effect between the second solder material 32 and the first region 12a and suppressing the occurrence of Kirkendall voids in the first region 12a.

[0075] Kirkendall voids can be suppressed on both the upper and lower sides of the semiconductor element 40, and deterioration of the characteristics of the semiconductor device 103 can be suppressed. According to the semiconductor device 103 of this embodiment, compared to the semiconductor device 101 of the first embodiment, the generation of Kirkendall voids can be further suppressed, and deterioration of the characteristics of the semiconductor device can be suppressed.

[0076] (Fourth embodiment) 8 is a cross-sectional view showing a semiconductor device 104 according to a fourth embodiment. A description of parts common to the semiconductor device 103 according to the third embodiment will be partially omitted.

[0077] 8 differs from the semiconductor device 103 according to the third embodiment in the structure between the first region 12a and the second exposed portion 12p. In addition to the first region 12a and the second exposed portion 12p, the second conductive member 12 further includes a second region 12b, a third conductive film 23, a third solder material 33, a fourth conductive film 24, and a third region 12c.

[0078] The second region 12b is formed continuously with the first region 12a. The second region 12b is, for example, a metal containing Cu. Between the first region 12a and the second region 12b, a portion may be provided that is located at a different position in the Z direction from the first region 12a and the second region 12b. For example, as shown in FIG. 8, the second region 12b is located in the positive direction of the Z direction from the first region 12a and the second region 12b, and a structure that suppresses short circuit defects due to the second solder material 32 is possible.

[0079] The third conductive film 23 is formed between the second region 12b and the third solder material 33. The third conductive film 23 is, for example, a metal containing Ni, and may be formed from the same material as the second conductive film 22. The third conductive film 23 is formed, for example, by a plating process.

[0080] The third solder material 33 is provided between the third conductive film 23 and the fourth conductive film 24. The third solder material 33 is, for example, a solder containing Sn. The third solder material 33 may be formed from the same material as the first solder material 31 and the second solder material 32.

[0081] The fourth conductive film 24 is formed between the third solder material 33 and the third region 12c. The fourth conductive film 24 is, for example, a metal containing Ni, and may be formed from the same material as the third conductive film 23.

[0082] The third region 12c is provided under the fourth conductive film 24 and is formed, for example, continuously with the second exposed portion 12p. It is preferable that the fourth conductive film 24 is formed in the third region 12c, while the fourth conductive film 24 is not formed in the second exposed portion 12p.

[0083] The region located between the third region 12c and the second exposed portion 12p is called the second peripheral region 12r. Even if the third region 12c and the second exposed portion 12p are integrally formed, it is preferable that the fourth conductive film 24 is selectively formed between the third solder material 33 and the third region 12c and not provided in the second peripheral region 12r. This can improve the adhesion between the second conductive member 12 and the resin portion 50.

[0084] The portion including the second exposed portion 12p and the third region 12c is formed, for example, from the same material as the first conductive member 11. An example of a process for forming the second exposed portion 12p and the third region 12c will be described below.

[0085] First, the first exposed portion 11p of the first conductive member 11 to the second exposed portion 12p of the second conductive member 12 are prepared as a continuous single conductive member. Next, the single conductive member is cut to obtain the first conductive member 11 shown in FIG. 8 as the side including the first exposed portion 11p. On the other hand, the side including the second exposed portion 12p requires a further process of bending the conductive member. Through the process of bending the conductive member, a step is provided in the Z direction between the second exposed portion 12p and the third region 12c, thereby obtaining the structure shown in FIG. 8.

[0086] 8, the process of forming first conductive member 11 and the process of forming the portion of second conductive member 12 extending from second exposed portion 12p to third region 12c can be performed partially at the same time. In semiconductor device 103 according to the third embodiment, second conductive member 12 must be prepared separately from first conductive member 11. On the other hand, according to this embodiment, first conductive member 11 and part of second conductive member 12 can be formed from the same material, which allows for efficient manufacturing.

[0087] According to the semiconductor device 104 of this embodiment, the second conductive member 12 has the second region 12b and the third region 12c electrically connected to the second region 12b by the third solder material 33, and the member including the third region 12c can be formed from the same material as the first conductive member 11. Therefore, it is possible to improve the manufacturing efficiency and reduce the manufacturing cost.

[0088] Furthermore, the second conductive member 12 is not integrally formed, and a third solder material 33 is provided between the second region 12b and the third region 12c. By forming the third conductive film 23 and the fourth conductive film 24, the Kirkendall effect can be suppressed between the second region 12b and the third solder material 33, and between the third region 12c and the third solder material 33.

[0089] On the other hand, it is desirable to selectively provide the fourth conductive film 24 below the third solder material 33. By preventing the fourth conductive film 24 from coming into contact with the resin portion 50 in the second peripheral region 12r, it is possible to improve the adhesion between the second conductive member 12 and the resin portion 50.

[0090] According to the semiconductor device 104 of this embodiment, the efficiency of manufacturing the first conductive member 11 and the second conductive member 12 can be improved, and the occurrence of Kirkendall voids between the second region 12b and the third region 12c and the third solder material 33 can be suppressed, thereby reducing the risk of resin peeling in the second peripheral region 12r.

[0091] Fifth embodiment 9 is a cross-sectional view of a semiconductor device 105 according to a fifth embodiment. Some of the common parts with the semiconductor device 104 according to the fourth embodiment will not be described.

[0092] 9, the second conductive film 22 is formed continuously from the first region 12a to the second region 12b. The second conductive film 22 is a metal containing, for example, Ni.

[0093] In Fig. 8, the second conductive film 22 and the third conductive film 23 are illustrated as separate conductive films formed at a distance from each other. On the other hand, as shown in Fig. 9, a structure in which the second conductive film 22 is continuously formed from the first region 12a to the second region 12b can be formed by uniformly plating the entire surface. Compared to the case of selectively plating as in the case of the semiconductor device 104 according to the fourth embodiment, the manufacturing cost can be reduced because no mask formation is required.

[0094] Of the portion including the first region 12a and the second region 12b, the second conductive film 22 is provided only on the lower surface facing the second solder material 32 and the third solder material 33. In other words, on the opposite surface, the second conductive member 12 is in contact with the resin part 50. The second conductive member 12 is a metal containing, for example, Cu, and can improve adhesion with the resin part on the upper surface.

[0095] According to the semiconductor device 105 of this embodiment, the second conductive film 22 is integrally formed from the first region 12a to the second region 12b, thereby making it possible to reduce manufacturing costs.

[0096] Between the first region 12a and the second region 12b, there is a portion where the second conductive film 22 and the resin portion 50 contact each other, and there is a possibility that the resin may peel off. However, the interface between the second conductive film 22 and the resin portion 50 is located in the resin portion 50 away from the first exposed portion 11p and the second exposed portion 12p, and this reduces the possibility that a crack caused by the resin peeling will reach the vicinity of the first exposed portion 11p and the second exposed portion 12p, causing moisture or the like to invade from the outside.

[0097] According to at least one of the embodiments described above, by forming the first conductive film 21 at least partially between the first conductive member 11 and the first solder material 31, Kirkendall voids are suppressed and deterioration of the characteristics of the semiconductor device is suppressed, and at the same time, by not forming the first conductive film 21 in at least a portion of the first peripheral region 11r, peeling of the resin portion 50 is suppressed and the reliability of the semiconductor device is improved.

[0098] The above describes the embodiments with reference to specific examples. However, the embodiments are not limited to these specific examples. In other words, designs that are appropriately modified by a person skilled in the art from these specific examples are also included within the scope of the embodiments as long as they have the characteristics of the embodiments. The elements, arrangements, materials, conditions, shapes, sizes, etc. of each of the above-mentioned specific examples are not limited to those exemplified, and can be appropriately modified.

[0099] In addition, the elements of each of the above-described embodiments can be combined to the extent technically possible, and combinations of these are also included in the scope of the embodiments as long as they include the features of the embodiments. In addition, within the scope of the concept of the embodiments, a person skilled in the art may come up with various modifications and alterations, and it is understood that these modifications and alterations also belong to the scope of the embodiments.

[0100] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0101] 101, 102, 103, 104, 105... Semiconductor device 11... First conductive member 12...Second conductive member 13...Third conductive member 11r...First peripheral area 11p...1st exposed part 12p...2nd exposed part 12a...First area 12b...Second area 12c...Third area 12r: Second peripheral area 21... First conductive film 22...Second conductive film 23...Third conductive film 24...Fourth conductive film 31...First solder material 32...Second solder material 33...Third solder material 40 Semiconductor element 50...Resin part

Claims

1. A first conductive member; a first conductive film provided on a portion of the first conductive member and including a metal element having a smaller diffusion coefficient than the first conductive member; a first solder material covering the first conductive film; a semiconductor element provided on the first solder material; A second solder material provided on the semiconductor element; a second conductive member having a first region facing the semiconductor element via the second solder material; a resin portion that seals the first conductive member, the second conductive member, the first conductive film, the first solder material, the second solder material, and the semiconductor element; a first peripheral region of the first conductive member that is located around a region where the semiconductor element overlaps and that is in direct contact with the resin portion; The semiconductor device has

2. the first conductive member has a first exposed portion exposed from the resin portion, The first peripheral region and the resin portion are in direct contact with each other in a vicinity of the first exposed portion in the first peripheral region. The semiconductor device according to claim 1 .

3. A first conductive member; a first conductive film provided on a portion of the first conductive member and including a metal element having a smaller diffusion coefficient than the first conductive member; a first solder material provided on the first conductive film and facing the first conductive member via the first conductive film; a semiconductor element provided on the first solder material; A second solder material provided on the semiconductor element; a second conductive member having a first region facing the semiconductor element via the second solder material; a resin portion that seals a portion of the first conductive member, the second conductive member, the first conductive film, the first solder material, the second solder material, and the semiconductor element; a first peripheral region of the first conductive member that is located around a region where the semiconductor element overlaps and that is in direct contact with at least a portion of the resin portion; having the first conductive member has a first exposed portion exposed from the resin portion, The first peripheral region and the resin portion are in direct contact with each other in a vicinity of the first exposed portion in the first peripheral region. Semiconductor device.

4. 4. The semiconductor device according to claim 1, further comprising a second conductive film formed at least partially between the first region and the second solder material, the second conductive film containing a metal element having a smaller diffusion coefficient than the metal element constituting the first region.

5. The second conductive member is a second exposed portion exposed from the resin portion; a second region provided between the second exposed portion of the second conductive member and the first region and formed continuously with the first region; a third region formed continuously with the second exposed portion and spaced apart from the second region; a third solder material provided between the second region and the third region; a third conductive film provided at least partially between the second region and the third solder material; a fourth conductive film provided at least partially between the third region and the third solder material; Further comprising The semiconductor device according to claim 4.

6. the second conductive film is formed continuously with the third conductive film from between the first region and the first solder material to between the second region and the third solder material; The semiconductor device according to claim 5 .

7. the second conductive member further has a second peripheral region located between the third region and the second exposed portion and in direct contact with the resin portion. The semiconductor device according to claim 6.

8. the first conductive member is a metal containing Cu, the first conductive film is a metal containing Ni, The first solder material is a metal containing Sn. The semiconductor device according to claim 4.

9. The first solder material contains Sn in a mass percent concentration of 50% or more. The semiconductor device according to claim 8.

10. The first solder material contains at least one of Pb, Sb, Ni, Ag, Bi, Cu, and Zn. The semiconductor device according to claim 9.

11. The semiconductor element has a MOSFET formed thereon, the first conductive member is electrically connected to a drain electrode of a MOSFET; The second conductive member is electrically connected to a source electrode of a MOSFET. The semiconductor device according to claim 5 .

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