Semiconductor device

Abstract

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 including a metal element having a diffusion coefficient smaller than that of 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 including a first region facing the semiconductor element with the second solder interposed therebetween; a resin 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 of the first conductive member, which is in direct contact with the resin, and which is located around a region where the semiconductor element overlaps.

Description

[0001] Cross - reference to related applications This application is based on and claims the priority of Japanese Patent Application No. 2023 - 198843, filed on November 24, 2023, the entire content of which is incorporated herein by reference. Technical field

[0002] Embodiments of the present invention generally relate to semiconductor devices. Background art

[0003] Soft solder can be used to join semiconductor elements and conductive members such as die pads. For example, when the soft solder contains Sn - containing metal and the die pad contains Cu - containing metal, there is a risk of Kirkendall voids being generated in the die pad due to the mutual diffusion between different metal elements. Summary of the invention

[0004] A semiconductor device according to an embodiment includes: A first conductive member; A first conductive film provided on a part of the first conductive member and containing a metal element having a diffusion coefficient smaller than that of 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 including a first region facing the semiconductor element with the second solder material interposed therebetween; A resin 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 of the first conductive member in contact with the resin portion and located around the region where the semiconductor element overlaps.

[0005] This embodiment can provide a semiconductor device in which the generation of Kirkendall voids is suppressed and the reliability is improved. Brief description of the drawings

[0006] Figure 1 FIG. is a perspective view showing a semiconductor device 101 according to the first embodiment.

[0007] Figure 2 FIG. is a perspective view showing the internal wiring structure of the semiconductor device 101 according to the first embodiment.

[0008] Figure 3 FIG. is a cross - sectional view taken along the line A - A' shown in Figure 2 FIG.

[0009] Figure 4A A top view showing the positional relationship between the first conductive film 21 and the first welding material 31.

[0010] Figure 4B A top view showing the positional relationship between the first conductive film 21 and the first welding material 31.

[0011] Figure 4C A top view showing the positional relationship between the first conductive film 21 and the first welding material 31.

[0012] Figure 5 A cross-sectional view showing the semiconductor device 102 according to the second embodiment.

[0013] Figure 6 A top view showing the positional relationship between the first conductive film 21 and the first welding material 31.

[0014] Figure 7 A cross-sectional view showing the semiconductor device 103 according to the third embodiment.

[0015] Figure 8 A cross-sectional view showing the semiconductor device 104 according to the fourth embodiment.

[0016] Figure 9 A cross-sectional view showing the semiconductor device 105 according to the fifth embodiment. Detailed Description

[0017] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0018] The semiconductor device according to the embodiment includes: a first conductive member; a first conductive film provided on a part of the first conductive member and containing a metal element having a diffusion coefficient smaller than that of the first conductive member; a first welding material provided on the first conductive film; a semiconductor element provided on the first welding material; a second welding material provided on the semiconductor element; a second conductive member including a first region facing the semiconductor element with the second welding material interposed therebetween; a resin sealing the first conductive member, the second conductive member, the first conductive film, the first welding material, the second welding material, and the semiconductor element; and a first peripheral region of the first conductive member that contacts the resin and is located around a region where the semiconductor element overlaps.

[0019] Note that the accompanying drawings are schematic or conceptual. For example, the relationship between the thickness and width of each part and the dimensional ratios between these parts may not necessarily be the same as those of the actual parts. Additionally, even when representing the same part, the dimensions and ratios may be shown differently in the accompanying drawings.

[0020] For example, some laminated structures are shown in the cross-sectional views described in the specification of the present application. However, the thickness ratios of the layers in the laminated structure are not necessarily the same as those of the actual layers. Even when one layer is shown to be thicker than another layer in each cross-sectional view, in reality, the thicknesses of one layer and another layer may be substantially the same as each other, or one layer may be thinner than another layer. That is, the dimensions such as thickness shown in the accompanying drawings in the specification of the present application may be different from the actual dimensions.

[0021] The direction from the first conductive member 11 toward the semiconductor element 40 is defined as the Z direction (first direction). Additionally, the direction orthogonal to the Z direction is defined as the X direction (second direction), and the direction intersecting the X direction and the Z direction is defined as the Y direction (third direction). Figure 3 The semiconductor device 101 shown is in a cross-sectional view on the X-Z plane. Note that the X direction, Y direction, and Z direction shown as orthogonal in this embodiment are not limited to an orthogonal relationship, but may be a relationship in which the directions intersect each other.

[0022] Additionally, for the sake of explanation, the positive direction of the Z direction is referred to as "up", and the negative direction of the Z direction is referred to as "down". However, the "up" and "down" directions are not limited to the direction of gravity or the direction when the semiconductor device is mounted.

[0023] Note that in the specification and each of the accompanying drawings of the present application, elements that are the same as those previously described in the accompanying drawings of the previous description are assigned the same reference numerals and the detailed description is omitted as appropriate.

[0024] (First Embodiment) Figure 1 and Figure 2 are perspective views respectively showing the semiconductor device 101 according to the first embodiment. Figure 1 shows the appearance including the resin 50, Figure 2 shows an example of the internal wiring structure. As Figure 1 shown, portions of the first conductive member 11 and the second conductive member 12 included in the semiconductor device 101 protrude from the resin 50. The first conductive member 11 is, for example, a lead frame. Multiple said portions of each of the first conductive member 11 and the second conductive member 12 may be exposed from the resin 50. Note that the case where a part is exposed includes the case where a part protrudes as shown in Figure 1 and Figure 2 shown and the case where a part is exposed on the lower surface of the package.

[0025] Figure 2 shows the Figure 1 internal wiring structure sealed by the resin 50 shown. The semiconductor element 40 is disposed between the first conductive member 11 and the second conductive member 12. In the second conductive member 12, the region facing the semiconductor element 40 in the Z direction is referred to as the first region 12a. The semiconductor element 40 is sealed by the resin 50. The first conductive member 11 and the second conductive member 12 are each electrically coupled to the semiconductor element 40. A part of the first conductive member 11 and a part of the second conductive member 12 are sealed by the resin 50.

[0026] For example, a metal oxide semiconductor field effect transistor (MOSFET) is formed in the semiconductor element 40. The first conductive member 11 is coupled to, for example, the drain electrode of the semiconductor element 40, and the second conductive member 12 is coupled to, for example, the source electrode. In addition, the semiconductor device 101 may further include a third conductive member 13. The third conductive member 13 is electrically coupled to, for example, the gate electrode of the MOSFET. The third conductive member 13 is not limited to Figure 2 the plate-like member shown. The third conductive member 13 may include, for example, a bonding wire.

[0027] The first conductive member 11 includes first protrusions 11p that respectively protrude from the resin 50. Figure 2 The first protrusions 11p provided at 4 in may not necessarily be provided at 4. In addition, the second conductive member 12 includes second protrusions 12p that respectively protrude from the resin 50. Figure 2 The second protrusions 12p provided at 3 in may not necessarily be provided at 3.

[0028] The shapes of the first protrusions 11p and the second protrusions 12p are not limited to Figure 2 the shapes shown. For example, the shapes may be respectively gull-wing shaped or J-shaped. The gull-wing shape is a shape having steps at different positions in the Z direction. Steps are provided toward the ends of the first protrusions 11p or the second protrusions 12p in the negative direction of the Z direction. The J-shaped is a shape in which, for example, each of the first protrusions 11p is bent in the X-Z plane and the end of each of the first protrusions 11p points in the positive direction of the X direction. In addition, the first protrusions 11p and the second protrusions 12p do not need to protrude from the resin 50 in the X direction, and external electrical coupling may be allowed on the lower surface of the resin 50.

[0029] Figure 3 shows a cross-section taken along Figure 2 the line A-A' shown. The A-A' cross-section is a cross-section passing through Figure 2 one of the first protrusions 11p of the first conductive member 11 and one of the second protrusions 12p of the second conductive member 12 shown.

[0030] A first conductive film 21, a first solder material 31, a semiconductor element 40, and a second solder material 32 are provided between a first conductive member 11 and a second conductive member 12. The first conductive film 21 is provided on a part of the first conductive member 11. The first solder material 31 is provided on the first conductive film 21 and contacts at least a part of a part of the first conductive member 11 and the first conductive film 21. The semiconductor element 40 is provided on the first solder material 31.

[0031] The first conductive film 21 is not provided on the first protrusion 11p of the first conductive member 11. The first conductive film 21 covered by the first solder material 31 and not in contact with the resin 50 is preferable because, as described later, this can improve the adhesion of the resin 50.

[0032] The second conductive member 12 includes a first region 12a facing the semiconductor element 40 in the Z direction. The 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 across the second solder material 32 and are electrically coupled to each other.

[0033] The first conductive member 11 and the second conductive member 12 include, for example, a Cu-containing metal. The first conductive member 11 and the second conductive member 12 may each include the same material.

[0034] The first conductive film 21 includes, for example, a Ni-containing metal. The first conductive film 21 functions as a barrier metal on the bonding surface between the first conductive member 11 and the first solder material 31. The first conductive film 21 includes a metal element having a diffusion coefficient smaller than that of the first conductive member 11. Here, note that a smaller diffusion coefficient means a smaller possibility that metal atoms rarely move on the bonding surface between different kinds of metals. In other words, the diffusion coefficient quantifies the ease of atomic migration (i.e., the atomic migration rate).

[0035] The first solder material 31 and the second solder material 32 include, for example, a Sn-containing soft solder. The first solder material 31 and the second solder material 32 each include, for example, the same material. The first solder material 31 and the second solder material 32 may contain, for example, Sn at a mass percentage concentration of 50% or more. In addition to Sn, the first solder material 31 may further contain at least Pb, Sb, Ni, Ag, Bi, Cu, or Zn.

[0036] The resin 50 seals the first conductive film 21, the first solder material 31, the semiconductor element 40, the second solder material 32, a part of the first conductive member 11, and a part of the second conductive member 12. The resin 50 includes, for example, an epoxy resin.

[0037] The first conductive member 11 includes a first peripheral region 11r located around the region where the semiconductor element 40 overlaps. Here, note that the region where the semiconductor element 40 overlaps refers to the region where the shadow of the semiconductor element 40 extends in the first conductive member 11 when the semiconductor element 40 is projected in one direction (e.g., the Z direction). As will be referred to Figure 3 as described, the first peripheral region 11r is a part of the upper surface of the first conductive member 11 and is positioned to surround the region where the first conductive member 11 contacts the first solder material 31 or the first conductive film 21 with each other. The first conductive member 11 is in direct contact with the resin 50 in at least a part of the first peripheral region 11r.

[0038] The first protrusion 11p and the second protrusion 12p protrude from the resin 50. The first protrusion 11p and the second protrusion 12p are provided for electrical coupling to an external electrode. For example, when a voltage is applied between one first protrusion 11p and one second protrusion 12p, current can flow from the first conductive member 11 through the semiconductor element 40 to the second conductive member 12.

[0039] The first peripheral region 11r does not include the first protrusion 11p that protrudes from the resin 50.

[0040] The above has been referred to Figure 3 to illustrate the cross-sectional view of the semiconductor device 101 according to the first embodiment.

[0041] Next, now will be referred to Figures 4A to 4C to illustrate 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. Figure 4A 、 Figure 4B and Figure 4C are X-Y plan views showing the first conductive member 11 and the first conductive film 21.

[0042] In Figures 4A to 4C , the resin 50 is located in the region surrounded by alternating long and short dashed lines. In addition, the first solder material 31 is located in the region surrounded by a dashed line. The hatching of the resin 50 and the first solder material 31 is omitted.

[0043] The first protrusion 11p protrudes from the resin 50. Figures 4A to 4C An example in which four first protrusions 11p are provided is shown. However, the present invention is not limited to these examples. Note that, for example, the first solder material 31 and the semiconductor element 40 on the first solder material 31 may have the same outer shape as each other. That is, the region surrounded by the dashed line can be regarded as the region where the first solder material 31 is located, or this region can be understood as the region where the semiconductor element 40 is located.

[0044] The first peripheral region 11r of the first conductive member 11 is a region surrounding the region where the semiconductor element 40 overlaps. The first peripheral region 11r is located around the semiconductor element 40 in the positive and negative directions of the X direction and the positive and negative directions of the Y direction. In Figures 4A to 4C it, the first peripheral region 11r is shown as the region outside the region (the region where the semiconductor element 40 is provided) indicated by a dotted line in the first conductive member 11, and does not include the first protrusion 11p.

[0045] Note that the shape of the first conductive film 21 can be determined according to the arrangement of the electrodes of the semiconductor element 40 provided on the first welding material 31. For example, it is preferably determined such that when viewed from the Z direction, the first conductive film 21 exists at a position overlapping the electrodes, which can suppress the generation of Kirkendall voids in the portion where the current mainly flows.

[0046] First, reference will be made to Figure 4A for description. The first conductive film 21 is covered by the first welding material 31 in the X-Y plane. Therefore, the resin 50 does not contact the first conductive film 21. At least the first welding material 31 is located between the resin 50 and the first conductive film 21. In other words, the outer shape of the first conductive film 21 in the X-Y plane is smaller than the outer shape of the first welding material 31 (semiconductor element 40). In this case, a part of the first welding material 31 is in direct contact with the first conductive member 11.

[0047] In Figure 4A the illustrated example, the first conductive film 21 does not directly contact the resin 50. The first peripheral region 11r directly contacts the resin 50. In particular, the region of the first peripheral region 11r near the first protrusion 11p directly contacts the resin 50. In other words, the first peripheral region 11r in contact with the resin 50 is located between the first conductive film 21 and the first protrusion 11p.

[0048] Figure 4B shows a case where the shape of the first conductive film 21 is not square and has no corners. For a shape with corners, there is a risk that stress concentrates on the portion with a large curvature (small radius of curvature) in the interface between the first conductive film 21 and the first welding material 31. This stress can be alleviated, for example, by setting the first conductive film 21 to an oval or elliptical shape without corners.

[0049] In addition, as Figure 4C shown, the first conductive film 21 can be divided into multiple parts. Figure 4C shows a case where it is divided into 2 columns in both the X direction and the Y direction. However, finer division can be performed. In addition to this, it can also be divided into parts with different numbers in the X direction and the Y direction.

[0050] In Figure 4A 、Figure 4B and Figure 4C In Figure 4C , for example, the area of the region where the first conductive film 21 is provided may be within the range of 20% - 90% of the area of the region where the first solder material 31 is provided (the region surrounded by the dashed line). Additionally, the range of this area may be 30% - 80%.

[0051] With the semiconductor device 101 according to this embodiment, where the first conductive film 21 is provided on a part of the first conductive member 11 and is located between the first conductive member 11 and the first solder material 31, this can suppress the generation of Kirkendall voids in the first conductive member 11 and can suppress the deterioration of the characteristics of the semiconductor device. Moreover, the first conductive member 11 can be made to closely adhere to the resin 50 in the first peripheral region 11r, improving the adhesion of the resin 50 and enhancing the reliability of the semiconductor device.

[0052] With the semiconductor device 101 according to this embodiment, the generation of Kirkendall voids can be suppressed. Here, for the purpose of explanation, an example where the first conductive member 11 contains Cu, the first conductive film 21 contains Ni, and the first solder material 31 contains Sn will now be described.

[0053] First, consider the 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. An alloy containing Cu and Sn is formed at the interface where the Cu-containing metal and the Sn-containing metal are joined. Cu atoms and Sn atoms diffuse at different rates at the interface, and the diffusion progress of Cu atoms is faster than that of Sn atoms (the diffusion coefficient is larger). As a result, the amount of Cu atoms diffusing from the first conductive member 11 towards the first solder material 31 is greater than the amount of Sn atoms diffusing in the reverse direction. As described above, the mutual diffusion effect at the interface where different metals are joined is called the Kirkendall effect.

[0054] Due to the different diffusion coefficients between Cu and Sn, Cu atoms disappear from the alloy region or interface generated in the first conductive member 11 containing Cu, resulting in voids. The voids generated due to the Kirkendall effect are called Kirkendall voids.

[0055] That is to say, when the first conductive member 11 containing Cu and the first solder material 31 containing Sn are in contact with each other, Kirkendall voids may be generated in the first conductive member 11. When Kirkendall voids are generated, the conductivity of the first conductive member 11 deteriorates. Therefore, there is a risk of an increase in the conduction voltage of the semiconductor element 40.

[0056] On the other hand, consider a case where a Ni-containing first conductive film 21 is provided similar to the semiconductor device 101 according to the present embodiment. The diffusion coefficient of Ni is smaller than that of Cu. Therefore, the Ni-containing first conductive film 21 can suppress the diffusion of atoms from the first conductive member 11 to the first solder material 31. Thus, Kirkendall voids in the first conductive member 11 can be suppressed.

[0057] By providing the first conductive film 21 at least in part between the first conductive member 11 and the first solder material 31, Kirkendall voids can be suppressed, thereby suppressing deterioration of the characteristics of the semiconductor device.

[0058] In addition, with the semiconductor device 101 according to the present embodiment, the adhesion of the resin 50 can be improved. Here, for the sake of explanation, an example in which the first conductive member 11 contains Cu and the first conductive film 21 contains Ni will now be described. The resin 50 includes, for example, an epoxy resin. It is known that the adhesion between Cu and an epoxy resin is better than the adhesion between Ni and an epoxy resin.

[0059] When the first conductive film 21 is formed on the entire upper surface of the first conductive member 11 and is also provided in the first peripheral region and the first protrusion 11p, different from the present embodiment, the adhesion of the resin 50 is reduced. One of the reasons is that the first conductive film 21 is also formed on the first peripheral region 11r, and the first conductive film 21 and the resin 50 are in direct contact with each other. Since the adhesion of the Ni-containing first conductive film 21 to the resin 50 containing an epoxy resin is lower than the adhesion of the Cu-containing first conductive member 11 to the resin 50 containing an epoxy resin, the risk of resin peeling may increase, reducing the reliability of the semiconductor device.

[0060] There is a risk that the peeling (crack) generated between the first conductive film 21 on the first peripheral region 11r and the resin 50 reaches the first solder material 31 or the semiconductor element 40 from the region near the first protrusion 11p. For example, when moisture or the like enters from the outside through the crack, there is a risk of performance deterioration 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, there is a risk of cracks in the resin 50, impairing the reliability of the semiconductor device.

[0061] On the other hand, according to the present embodiment, as Figure 3 shown, by not providing the first conductive film 21 in at least the vicinity of the first protrusion 11p in the first peripheral region 11r, the first conductive member 11 contacts the resin 50 at least in part in the first peripheral region 11r. Since the adhesion of the Cu-containing first conductive member 11 to the resin 50 is greater than the adhesion of the Ni-containing first conductive film 21 to the resin 50, the risk of resin peeling in the first peripheral region 11r is small.

[0062] AsFigure 4A As shown, the first conductive film 21 is covered by the first welding material 31, for example. In other words, the first conductive film 21 does not contact the resin 50. By covering the first conductive film 21 with the first welding material 31, it is possible to suppress a decrease in the adhesion caused when the first conductive film 21 and the resin 50 come into contact with each other. In order to improve the adhesion of the resin 50, it is preferable that the first conductive film 21 is covered by the first welding material 31.

[0063] With the semiconductor device 101 according to the present embodiment, the resin 50 and the first conductive member 11 are in contact with each other in the first peripheral region 11r, suppressing resin peeling in the first peripheral region 11r and improving the reliability of the semiconductor device. In order to improve the adhesion of the resin 50, it is preferable that the first conductive film 21 is covered by the first welding material 31.

[0064] Note that when the first conductive film 21 is covered by the first welding material 31, the adhesion of the resin 50 can be more reliably improved. Even if, for example, a positional deviation occurs when the first welding material 31 and the semiconductor element 40 are provided in the case where the first conductive film 21 is formed as shown, as long as the degree of the positional deviation is equal to or less than a predetermined amplitude, the first conductive film 21 will not protrude from the first welding material 31. If a positional deviation occurs in the case where the first conductive film 21 having the same outer dimensions as the first conductive member 11 or the semiconductor element 40 is formed, there is a risk that the first conductive film 21 will protrude from the first welding material 31. Figure 4A As shown

[0065] With the semiconductor device 101 according to the present embodiment, the first conductive film 21 is formed in at least a part between the first conductive member 11 and the first welding material 31, which makes it possible to suppress Kirkendall voids and suppress deterioration of the characteristics of the semiconductor device. In addition, by not forming the first conductive film 21 in at least a part of the first peripheral region 11r, it is also possible to suppress peeling of the resin 50 and improve the reliability of the semiconductor device.

[0066] (Second Embodiment) Figure 5 FIG. is a cross-sectional view taken along line A - A' of the semiconductor device 102 according to the second embodiment. When referring to the cross-sectional view taken along line A - A', in each embodiment, it means a cross-sectional view taken at a position corresponding to the line A - A' shown in accordance with the first embodiment. Figure 2 As shown Figure 6 FIG. is a plan view showing the arrangement of the first conductive film 21 in the second embodiment. Description of parts common to the semiconductor device 101 according to the first embodiment will be omitted.

[0067] First, the cross-sectional structure will be described with reference to Figure 5 As Figure 5As shown, the first conductive film 21 is provided on a part of the first conductive member 11. The first welding material 31 is provided on the first conductive film 21. The first conductive film 21 is provided between the first welding material 31 and the first conductive member 11, and the first welding material 31 and the first conductive member 11 do not directly contact each other.

[0068] A part of the first conductive film 21 contacts the resin 50. At least a part of the first peripheral region 11r of the first conductive member 11 directly contacts the resin 50. The first conductive film 21 protruding from the first welding material 31 is provided in a part of the first peripheral region 11r. In a part of the first peripheral region 11r, the first conductive member 11 and the resin 50 face each other with the first conductive film 21 therebetween.

[0069] On the other hand, the first conductive film 21 is not provided near the first protrusion 11p in the first peripheral region 11r. In other words, the first protrusion 11p and the first conductive film 21 are separated from each other. The first peripheral region 11r in contact with the resin 50 is provided between the first protrusion 11p and the first conductive film 21.

[0070] Next, the positional relationship between the first conductive film 21 and the first welding material 31 will now be described with reference to Figure 6 Except for the shape of the first conductive film 21, Figure 6 the configuration shown is the same as that of Figure 4A , Figure 4B and Figure 4C shown. For example, in Figure 6 , the resin 50 is located in the region surrounded by the alternately long and short dashed lines. The first welding material 31 is located in the region surrounded by the dashed line. In addition, it can be understood that the region surrounded by the dashed line represents the semiconductor element 40 provided on the first welding material 31. The hatching of the resin 50 and the first welding material 31 is omitted.

[0071] The first welding material 31 is formed on the first conductive film 21. The area where the first welding material 31 is provided is smaller than the area where the first conductive film 21 is provided. The first conductive film 21 is located between the first welding material 31 and the first conductive member 11.

[0072] The first peripheral region 11r of the first conductive member 11 is located around the region where the semiconductor element 40 overlaps in the positive and negative directions of the X direction and the positive and negative directions of the Y direction. The first conductive film 21 is provided in at least a part of the first peripheral region 11r in the positive and negative directions of the X direction and the positive and negative directions of the Y direction, respectively. However, the first conductive film 21 is separated from the first protrusion 11p.

[0073] That is to say, as long as the first conductive film 21 does not reach the first protrusion 11p, the first conductive film 21 can be formed to have a large area protruding from the first welding material 31. In the positive direction of the X direction and the positive and negative directions of the Y direction of the first conductive member, the first conductive film 21 can be formed to be larger than Figure 6 the area in the case shown.

[0074] For example, the first conductive film 21 can be formed on the entire surface of the first peripheral region 11r except for the region near the first protrusion 11p. That is, the first conductive film 21 is formed by plating, for example. However, the mask for plating is limited to the region near the first protrusion 11p in the first peripheral region 11r. In other words, the mask for plating only needs to cover at least the first protrusion 11p. It is not necessary to form a mask in the region further in the positive X direction than the predetermined position between the first protrusion 11p and the semiconductor element 40 in the X direction, which makes mask formation easier.

[0075] With the semiconductor device 102 according to the second embodiment, in which the first conductive film 21 is set to have a larger area than the first conductive film 21 in the semiconductor device 101 according to the first embodiment, resin peeling near the first protrusion 11p in the first peripheral region 11r can be suppressed, and the reliability of the semiconductor device can be improved. In addition, compared with the semiconductor device 101 according to the first embodiment, the generation of Kirkendall voids can be further suppressed, and the deterioration of the characteristics of the semiconductor device can be suppressed.

[0076] In Figure 5 the semiconductor device 102 shown, the first conductive film 2 is set to be wider than the first conductive film in the semiconductor device 101 according to the first embodiment. However, the first conductive film 21 is not formed near the first protrusion 11p in the first peripheral region 11r. That is to say, even if the first conductive film 21 and the resin 50 come into contact with each other in the first peripheral region 11r, it is in the region close to the semiconductor element 40. Even if resin peeling occurs, the growth of cracks and the situation of reaching one of the first protrusions 11p can be suppressed. One of the reasons is that in the region near the first protrusion 11p in the first peripheral region 11r, the first peripheral region 11r and the resin 50 are in direct contact with each other, resulting in a high adhesion. Resin peeling near the first protrusion 11p in the first peripheral region 11r is suppressed. The entry of, for example, moisture and the like from the outside into the resin 50 is suppressed.

[0077] In addition, as Figure 6As shown, the first conductive film 21 is formed to have an area larger than that of the first welding material 31, so that the contact between the first conductive member 11 and the first welding material 31 can be reliably suppressed. Even if there is a positional deviation in the first welding material 31 or the semiconductor element 40, the wide first conductive film 21 can suppress the contact between the first welding material 31 and the first conductive member 11.

[0078] That is, according to this embodiment, the first conductive film 21 can be formed more reliably between the first conductive member 11 and the first welding material 31, instead of allowing the first conductive film 21 and the resin 50 to partially contact each other. Since the first conductive film 21 can suppress the generation of Kirkendall voids, the deterioration of the characteristics of the semiconductor device can be further suppressed compared with the first embodiment.

[0079] (Third Embodiment) Figure 7 FIG. is a cross-sectional view of a semiconductor device 103 according to the third embodiment. The description of the parts common to the semiconductor device 101 according to the first embodiment will be omitted.

[0080] The second conductive film 22 is provided on at least a part between the second welding material 32 and the first region 12a of the second conductive member 12. The second conductive film 22 is covered by the second welding material 32. In other words, the second conductive film 22 does not contact the resin 50.

[0081] The second conductive film 22 contains a metal element having a diffusion coefficient smaller than that of the metal element forming the first region 12a of the second conductive member 12. The second welding material 32 includes, for example, a Sn-containing soft solder. The second conductive film 22 includes, for example, a Ni-containing metal. The first region 12a of the second conductive member 12 includes, for example, a Cu-containing metal.

[0082] The second conductive film 22 is, for example, a Ni-containing metal film provided on at least a part between the Sn-containing metal and the Cu-containing metal. The second conductive film 22 functions as a barrier metal for suppressing the Kirkendall effect generated between the Sn-containing metal and the Cu-containing metal.

[0083] In addition, for the shape of the second conductive film 22, similar to the case described with reference to Figure 4A , Figure 4B and Figure 4C , various shapes such as a square or an oval can be adopted, and it can be divided into multiple parts.

[0084] By using the semiconductor device 103 according to the present embodiment, in which the second conductive film 22 is provided on at least a part between the second solder 32 and the first region 12a, the Kirkendall effect between the second solder 32 and the first region 12a can be suppressed, so that the generation of Kirkendall voids in the first region 12a can be suppressed.

[0085] Kirkendall voids can be suppressed on both the upper and lower sides of the semiconductor element 40, so that the deterioration of the characteristics of the semiconductor device 103 can be suppressed. By using the semiconductor device 103 according to the present embodiment, compared with the semiconductor device 101 according to the first embodiment, the generation of Kirkendall voids can be further suppressed, and thus the deterioration of the characteristics of the semiconductor device can be suppressed.

[0086] (Fourth Embodiment) Figure 8 FIG. is a cross-sectional view showing a semiconductor device 104 according to the fourth embodiment. Descriptions common to the semiconductor device 103 of the third embodiment are partially omitted.

[0087] Figure 8 The second conductive member 12 shown is different from the semiconductor device 103 of the third embodiment in the structure between the first region 12a and the second protrusion 12p. In addition to the first region 12a and the second protrusion 12p, the second conductive member 12 further includes a second region 12b, a third conductive film 23, a third solder 33, a fourth conductive film 24, and a third region 12c.

[0088] The second region 12b is formed continuously with the first region 12a. The second region 12b includes, for example, a Cu-containing metal. A portion having a different position in the Z direction from the first region 12a and the second region 12b may be provided between the first region 12a and the second region 12b. For example, as Figure 8 shown, it is located in the positive direction of the Z direction compared with the first region 12a and the second region 12b, so that a structure for suppressing a short-circuit failure caused by the second solder 32 can be provided.

[0089] The third conductive film 23 is formed between the second region 12b and the third solder 33. The third conductive film 23 includes, for example, a Ni-containing metal and may be formed of the same material as the second conductive film 22. The third conductive film 23 is formed by plating, for example.

[0090] The third solder 33 is provided between the third conductive film 23 and the fourth conductive film 24. The third solder 33 includes, for example, a Sn-containing soft solder. The third solder 33 may also be formed of the same material as the first solder 31 and the second solder 32.

[0091] The fourth conductive film 24 is formed between the third welding material 33 and the third region 12c. The fourth conductive film 24 includes, for example, a Ni-containing metal and may be formed of the same material as the third conductive film 23.

[0092] The third region 12c is provided below the fourth conductive film 24 and is formed, for example, continuously with the second protrusion 12p. Preferably, the fourth conductive film 24 is formed on the third region 12c and not on the second protrusion 12p.

[0093] The region between the third region 12c and the second protrusion 12p is referred to as the second peripheral region 12r. Even when the third region 12c and the second protrusion 12p are integrally formed, it is preferable to selectively form the fourth conductive film 24 between the third welding material 33 and the third region 12c, and not to provide the fourth conductive film 24 in the second peripheral region 12r. The adhesion between the second conductive member 12 and the resin 50 can be improved.

[0094] Note that, for example, the portion including the second protrusion 12p and the third region 12c is formed of the same material as the first conductive member 11. Now, an example of the process for forming the second protrusion 12p and the third region 12c will be described herein.

[0095] First, a single conductive member continuous from the first protrusion 11p of the first conductive member 11 to the second protrusion 12p of the second conductive member 12 is prepared. Next, the single conductive member is cut to obtain Figure 8 the first conductive member 11 shown as the side including the first protrusion 11p. On the other hand, for the side including the second protrusion 12p, a process of bending the conductive member is further required. By the process of bending the conductive member, a step in the Z direction is provided between the second protrusion 12p and the third region 12c, and thus Figure 8 the structure shown can be obtained.

[0096] That is, for Figure 8 the structure shown, the process of forming the first conductive member 11 and the process of forming the portion of the second conductive member 12 that extends from the second protrusion 12p and reaches the third region 12c can be partially performed simultaneously. In the semiconductor device 103 according to the third embodiment, it is necessary to separately prepare the second conductive member 12 different from the first conductive member 11. On the other hand, according to the present embodiment, since the first conductive member 11 and a part of the second conductive member 12 can be formed of the same material, the manufacturing efficiency can be improved.

[0097] With the semiconductor device 104 according to the present embodiment, the second conductive member 12 may include a second region 12b and a third region 12c electrically coupled to the second region 12b through a third bonding material 33. The member including the third region 12c can be formed of the same material as the first conductive member 11. Therefore, manufacturing efficiency can be improved and manufacturing cost can be reduced.

[0098] In addition, the second conductive member 12 is not integrally formed. The third bonding material 33 is disposed between the second region 12b and the third region 12c. By providing the third conductive film 23 and the fourth conductive film 24, the Kirkendall effect between the second region 12b and the third bonding material 33 and between the third region 12c and the third bonding material 33 can be suppressed.

[0099] On the other hand, it is preferable to selectively provide the fourth conductive film 24 under the third bonding material 33. By preventing the fourth conductive film 24 and the resin 50 from being in close contact with each other in the second peripheral region 12r, the adhesion between the second conductive member 12 and the resin 50 can be improved.

[0100] With the semiconductor device 104 according to the present embodiment, the manufacturing efficiency of the first conductive member 11 and the second conductive member 12 can be improved. The generation of Kirkendall voids between the second region 12b, the third region 12c, and the third bonding material 33 can be suppressed. The risk of resin peeling in the second peripheral region 12r can be reduced.

[0101] (Fifth Embodiment) Figure 9 FIG. is a cross-sectional view of a semiconductor device 105 according to the fifth embodiment. Description of the common parts with the semiconductor device 104 according to the fourth embodiment will be omitted in part.

[0102] In Figure 9 , the second conductive film 22 is continuously formed from the first region 12a to the second region 12b. The second conductive film 22 includes, for example, a Ni-containing metal.

[0103] Figure 8 The second conductive film 22 and the third conductive film 23 are illustrated as conductive films formed separately from each other. On the other hand, as Figure 9 shown, by performing plating integrally and uniformly on the surface, 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. Compared with the case of selectively performing plating similar to the semiconductor device 104 according to the fourth embodiment, a mask does not need to be formed, so that manufacturing cost can be reduced.

[0104] The second conductive film 22 is provided only on the lower surface of the portion including the first region 12a and the second region 12b that faces the second welding material 32 and the third welding material 33. In other words, the second conductive member 12 is in contact with the resin 50 on the opposite surface. The second conductive member 12 includes, for example, a Cu-containing metal, which can improve the adhesion to the resin on the upper surface.

[0105] With the semiconductor device 105 according to the present embodiment, the second conductive film 22 extending from the first region 12a and reaching the second region 12b is integrally formed, so that the manufacturing cost can be reduced.

[0106] Note that between the first region 12a and the second region 12b, there is a portion where the second conductive film 22 and the resin 50 are in contact with each other, which may cause a risk of resin peeling. However, the interface between the second conductive film 22 and the resin 50 is located in the resin 50 at a position far from the first protrusion 11p and the second protrusion 12p, which can reduce the risk that cracks caused by resin peeling reach the region near one of the first protrusion 11p or the second protrusion 12p, allowing moisture to enter from the outside, for example.

[0107] According to at least one of the above embodiments, by forming the first conductive film 21 on at least a part between the first conductive member 11 and the first welding material 31, Kirkendall voids can be suppressed and the characteristic deterioration of the semiconductor device can be suppressed. At the same time, by not forming the first conductive film 21 on at least a part of the first peripheral region 11r, the peeling of the resin 50 can be suppressed and the reliability of the semiconductor device can be improved.

[0108] The embodiments have been described above with reference to specific examples. However, the embodiments are not limited to these specific examples. That is, a solution obtained by appropriately designing and changing these specific examples by those skilled in the art is also included in the scope of the embodiments as long as it exhibits the characteristics of the embodiments. For example, the components included in each of the above specific examples, their arrangements, materials, conditions, shapes, and sizes are not limited to those illustrated, and can be appropriately changed.

[0109] In addition, as long as it is technically feasible, the components included in the above embodiments can be combined. Such a combination is also included in the scope of the embodiments as long as it exhibits the characteristics of the embodiments. Furthermore, within the scope of the idea of the embodiments, those skilled in the art can conceive various modifications and corrections. It should be understood that these modifications and corrections also belong to the scope of the embodiments.

[0110] While some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the present invention. These novel embodiments can be implemented in various other forms. Various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the present invention, and are included in the invention described in the claims and its equivalents.

Claims

1. A semiconductor device, comprising: a first conductive member; a first conductive film provided on a portion of the first conductive member and containing a metal element having a diffusion coefficient smaller than that of the first conductive member; a first soldering material disposed on the first conductive film; A semiconductor element is disposed on the first soldering material; A second solder material is disposed on the semiconductor element; a second conductive member including a first region facing the semiconductor element via the second solder material; A resin 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; as well as The first peripheral region of the first conductive member is in contact with the resin and is located around a region overlapping the semiconductor element.

2. The semiconductor device according to claim 1, wherein The first conductive member includes a first protrusion exposed from the resin, and The first peripheral region and the resin are in direct contact with each other near the first protrusion in the first peripheral region.

3. The semiconductor device according to claim 1, wherein An area where the first solder material is provided is larger than an area where the first conductive film is provided.

4. The semiconductor device according to claim 1, wherein: A portion of the first welding material is in direct contact with the first conductive member.

5. The semiconductor device according to claim 1, wherein The area where the first conductive film is provided is 20% to 90% of the area where the first solder material is provided.

6. The semiconductor device according to claim 1, wherein An area where the first solder material is provided is smaller than an area where the first conductive film is provided.

7. The semiconductor device according to claim 1, wherein The first welding material and the first conductive member are not in direct contact with each other.

8. The semiconductor device according to claim 1, further comprising a second conductive film, the second conductive film being formed in at least a portion between the first region and the second solder material and containing a metal element having a diffusion coefficient smaller than a diffusion coefficient of a metal element forming the first region.

9. The semiconductor device according to claim 8, wherein the second conductive member further comprises: a second protrusion exposed from the resin; a second region provided between the second protrusion of the second conductive member and the first region and formed continuously with the first region; as well as The third region is formed continuously with the second projection and is separated from the second region.

10. The semiconductor device according to claim 9, further comprising: a third welding material disposed between the second region and the third region; as well as The third conductive film is provided in at least a portion between the second region and the third solder material.

11. The semiconductor device according to claim 10, further comprising: The fourth conductive film is provided in at least a portion between the third region and the third solder material.

12. The semiconductor device according to claim 10, wherein: The second conductive film and the third conductive film are continuously formed from a region between the first region and the first solder material to a region between the second region and the third solder material.

13. The semiconductor device according to claim 12, wherein: The second conductive member further includes a second peripheral region that is located between the third region and the second protrusion and is in direct contact with the resin.

14. The semiconductor device according to claim 1, wherein The first conductive member includes a metal containing Cu, The first conductive film is a metal containing Ni, and The first solder material includes a metal containing Sn.

15. The semiconductor device according to claim 1, wherein The first welding material contains Sn at a mass percent concentration of 50% or more.

16. The semiconductor device according to claim 1, wherein The first welding material contains at least Pb, Sb, Ni, Ag, Bi, Cu or Zn.

17. The semiconductor device according to claim 1, wherein forming a metal oxide semiconductor field effect transistor MOSFET in the semiconductor element, The first conductive member is electrically coupled to the drain electrode of the MOSFET, and The second conductive member is electrically coupled to a source electrode of the MOSFET.

18. A semiconductor device comprising: a first conductive member; a first conductive film provided on a portion of the first conductive member and containing a metal element having a diffusion coefficient smaller than that of the first conductive member; a first soldering material disposed on the first conductive film; A semiconductor element is disposed on the first soldering material; A second solder material is disposed on the semiconductor element; as well as a second conductive member including a first region facing the semiconductor element via the second solder material; The area where the first welding material is provided is larger than the area where the first conductive film is provided.

19. A semiconductor device comprising: a first conductive member; A first soldering material is disposed on the first conductive film; A semiconductor element is disposed on the first soldering material; A second solder material is disposed on the semiconductor element; a second conductive member including a first region facing the semiconductor element via the second solder material; The first conductive film is provided between the second solder material and the second conductive member and contains a metal element having a diffusion coefficient smaller than a diffusion coefficient of the second conductive member.

20. The semiconductor device according to claim 19, wherein An area where the second solder material is provided is larger than an area where the first conductive film is provided.

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