Semiconductor device

Abstract

The embodiment of the invention provides a semiconductor device capable of improving performance. A semiconductor device according to one embodiment includes: a first conductive member; a second conductive member; a semiconductor chip provided between the first conductive member and the second conductive member; a first connection member provided between the semiconductor chip and the second conductive member; and a thin film provided on the second conductive member and including a material different from that of the first connection member. The second conductive member has a first plate portion, a second plate portion, and a third plate portion. The first plate portion extends in a first direction along a first surface of the semiconductor chip, and is connected to the semiconductor chip via the first connection member. The second plate portion extends obliquely with respect to the first direction from the first plate portion. The third plate portion extends from the second plate portion in the first direction. The film is disposed on a surface of the second plate portion that is continuous with a surface on which the first connecting member is provided.

Description

[0001] Related applications

[0002] This application claims priority to Japanese Patent Application No. 2024-163642 (filed on September 20, 2024). This application incorporates the entire contents of the basic application by reference to that basic application. Technical Field

[0003] Embodiments of the present invention relate to semiconductor devices. Background Technology

[0004] A semiconductor device is known to include a semiconductor package containing a semiconductor chip. Summary of the Invention

[0005] Embodiments of the present invention provide semiconductor devices capable of improving performance.

[0006] One embodiment of a semiconductor device includes: a first conductive member; a second conductive member; a semiconductor chip disposed between the first conductive member and the second conductive member; a first connecting member disposed between the semiconductor chip and the second conductive member; and a thin film disposed on the second conductive member, comprising a material different from that of the first connecting member. The second conductive member has a first plate portion, a second plate portion, and a third plate portion. The first plate portion extends in a first direction along a first surface of the semiconductor chip and is connected to the semiconductor chip via the first connecting member. The second plate portion extends obliquely from the first plate portion relative to the first direction. The third plate portion extends from the second plate portion in the first direction. The thin film is disposed on a surface of the second plate portion that is continuous with the surface where the first connecting member is disposed. Attached Figure Description

[0007] Figure 1 This is a perspective view showing the external shape of the semiconductor device according to the first embodiment.

[0008] Figure 2 This is a top view showing the external shape of the semiconductor device according to the first embodiment.

[0009] Figure 3 This is a cross-sectional view showing the structure of the semiconductor device according to the first embodiment.

[0010] Figure 4 This is a cross-sectional view showing the connection structure between the semiconductor chip and the conductive component according to the first embodiment.

[0011] Figure 5 This is a cross-sectional view showing the connection structure between the semiconductor chip and the conductive component in a comparative example.

[0012] Figure 6 This is a cross-sectional view showing the connection structure between the semiconductor chip and the conductive component according to the second embodiment.

[0013] Figure 7 This is a cross-sectional view showing the connection structure between the semiconductor chip and the conductive component according to the third embodiment. Detailed Implementation

[0014] Hereinafter, embodiments will be described with reference to the accompanying drawings. In the following description, common reference numerals are used to denote constituent elements having the same function and structure. Furthermore, the embodiments shown below are illustrative of apparatuses and methods for embodying the technical concept of these embodiments, and are not intended to specifically limit the materials, shapes, structures, and arrangements of constituent components to the manner described below.

[0015] 1. First Implementation Method

[0016] The semiconductor device of the first embodiment will be described. Figure 1 This is a perspective view showing the external shape of the semiconductor device according to the first embodiment. Figure 2 This is a top view showing the external shape of the semiconductor device according to the first embodiment.

[0017] Figure 3 It is along Figure 1 and Figure 2 A cross-sectional view of the semiconductor device along line III-III. Figure 1 and Figure 2 This is an image obtained by transmission viewing of the resin component covering the semiconductor device. In the following description, in... Figures 1 to 3 In this diagram, the direction of the arrow pointing in the X direction is abbreviated as X direction, and the direction opposite to the arrow is abbreviated as -X direction. Similarly, the direction of the arrow pointing in the Y and Z directions is abbreviated as Y direction and Z direction respectively, and the direction opposite to the arrow is abbreviated as -Y direction and -Z direction respectively. Additionally, sometimes the Z direction is written as "up" and the -Z direction as "down".

[0018] like Figure 3 As shown, the semiconductor device 1 includes a semiconductor chip 10, conductive components 21-25, connecting components 31-33, and a resin component 40. The semiconductor chip 10 is disposed between the conductive components 21 and 23. Furthermore, the conductive component 23 is disposed on top of the conductive component 22.

[0019] Semiconductor chip 10 includes, for example, a MOS type field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). Here, the case where semiconductor chip 10 is a MOSFET will be described.

[0020] The semiconductor chip 10 includes, for example, a source electrode 10s, a drain electrode 10d, a gate electrode 10g, and a semiconductor layer 10a. The semiconductor layer 10a is disposed between the source electrode 10s and the drain electrode 10d. Furthermore, the source electrode 10s and the drain electrode 10d can be interchanged as needed.

[0021] The semiconductor chip 10 has a first surface and a second surface. The first surface is disposed on the Z-direction side, and the second surface is disposed on the -Z-direction side. A source electrode 10s is disposed on the first surface of the semiconductor chip 10. A drain electrode 10d is disposed on the second surface of the semiconductor chip 10.

[0022] The conductive component 21 is part of the lead frame on which the semiconductor chip 10 is mounted. The conductive component 21 has a base portion 21a and a plurality of protrusions 21b. The conductive component 21 mainly comprises, for example, a conductive material such as copper.

[0023] The base portion 21a is a region for mounting the semiconductor chip 10. The semiconductor chip 10 is disposed on the base portion 21a of the conductive member 21. The conductive member 21 is configured to face the drain electrode 10d of the semiconductor chip 10 and is electrically connected to the drain electrode 10d.

[0024] Multiple protrusions 21b are regions extending in the -X direction from the base portion 21a. The multiple protrusions 21b function as lead terminals (e.g., drain terminals) capable of enabling connection to the outside.

[0025] A connecting member 31 is provided between the semiconductor chip 10 and the conductive component 21. The connecting member 31 fixes the semiconductor chip 10 to the base portion 21a of the conductive component 21. Thus, the drain electrode 10d of the semiconductor chip 10 is electrically connected to the conductive component 21 via the connecting member 31. The connecting member 31 mainly comprises a conductive material such as solder or silver.

[0026] Multiple conductive components 22 are arranged with a spacing in the X direction relative to conductive components 21 and are arranged in the Y direction. The conductive components 22 are part of the lead frame. The conductive components 22 function as lead terminals (e.g., source terminals) enabling connection to the outside. The conductive components 22 primarily comprise, for example, a conductive material such as copper.

[0027] A conductive component 23 is disposed on the source electrode 10s and conductive component 22 of the semiconductor chip 10. The conductive component 23 is configured to face the source electrode 10s and conductive component 22 of the semiconductor chip 10 and to be electrically connected to the source electrode 10s and conductive component 22. The conductive component 23 mainly comprises, for example, a conductive material such as copper.

[0028] The conductive member 23 has a portion (or, a first plate portion) 23a, a portion (or, a second plate portion) 23b, a portion (or, a third plate portion) 23c, and a portion (or, a fourth plate portion) 23d. Portion 23a is a region that faces and is electrically connected to the semiconductor chip 10. Portion 23a is a region extending along the first surface of the semiconductor chip 10, i.e., a region extending linearly in the X direction. Portion 23d is a region that faces and is electrically connected to the conductive member 22. Portions 23b and 23c are regions between portions 23a and 23d, which are regions that do not face either the semiconductor chip 10 or the conductive member 22. Portion 23b is continuous with portion 23a and extends linearly from portion 23a in a direction inclined relative to both the X and Z directions. Portion 23c is continuous with portion 23b and extends linearly from portion 23b in the X direction. Furthermore, portion 23d is continuous with portion 23c, bends in the -Z direction from portion 23c, and extends along the upper surface of the conductive member 22, i.e., extends in a straight line in the X direction. With the configuration described above, by increasing the distance between portion 23c of the conductive member 23 and the conductive member 21, the insulation between the conductive member 23 and the conductive member 21 can be improved.

[0029] A thin film 51 is provided on the lower surface of portion 23b of the conductive component 23. Details about the thin film 51 will be described later.

[0030] A connecting member 32 is provided between a portion 23a of the conductive component 23 and the semiconductor chip 10. The connecting member 32 fixes the conductive component 23 to the semiconductor chip 10. Thus, the source electrode 10s of the semiconductor chip 10 is electrically connected to the conductive component 23 via the connecting member 32. The connecting member 32 mainly comprises a conductive material such as solder or silver.

[0031] A connecting member 33 is provided between portion 23d of the conductive member 23 and the conductive member 22. The connecting member 33 fixes the conductive member 23 to the conductive member 22. Thus, the conductive member 22 is electrically connected to the conductive member 23 via the connecting member 33. The connecting member 33 mainly comprises a conductive material such as solder or silver.

[0032] like Figure 1 and Figure 2As shown, conductive member 24 is disposed at a distance from conductive member 22 in the Y direction. Conductive member 24 is part of the lead frame. Conductive member 24 functions as a lead terminal (e.g., a gate terminal) capable of enabling connection to the outside. Conductive member 24 mainly comprises, for example, a conductive material such as copper.

[0033] A conductive member 25 is disposed on the gate electrode 10g and conductive member 24 of the semiconductor chip 10. The conductive member 25 is configured to face the gate electrode 10g and conductive member 24 of the semiconductor chip 10 and to be electrically connected to the gate electrode 10g and conductive member 24. The conductive member 25 mainly comprises, for example, a conductive material such as copper.

[0034] Furthermore, the resin component 40 covers the semiconductor chip 10, a portion of the conductive component 21, a portion of the conductive component 22, the conductive component 23, a portion of the conductive component 24, and the conductive component 25. The resin component 40 seals the semiconductor chip 10 and the conductive components 21 to 25 with resin.

[0035] Next, refer to Figure 4 The connection structure between the semiconductor chip 10 and the conductive component 23 will be described. Figure 4 yes Figure 3 The enlarged view of part A in the figure is a cross-sectional view showing the connection structure between the source electrode 10s of the semiconductor chip 10 and the conductive component 23.

[0036] As described above, the source electrode 10s of the semiconductor chip 10 is connected to a portion 23a of the conductive member 23 via the connection member 32. The conductive member 23 has a portion 23a extending linearly in the X direction, a portion 23b extending linearly from the portion 23a at an angle relative to the X and Z directions, and a portion 23c extending linearly from the portion 23b in the X direction.

[0037] A connecting member 32 is provided between the source electrode 10s of the semiconductor chip 10 and a portion 23a of the conductive member 23. A thin film 51 is provided on the lower surface of the portion 23b of the conductive member 23, that is, on the surface of the portion 23b in the X direction (or, -Z direction). In other words, a thin film 51 is provided on the lower surface of the portion 23b of the conductive member 23 on the connecting member 32, that is, on the surface continuous with the surface on which the connecting member 32 is provided. The thin film 51 is in contact with the connecting member 32.

[0038] Thin film 51 is disposed on a linearly extending surface (or region) of portion 23b of conductive member 23. Thin film 51 is disposed from the beginning of the linearly extending surface of portion 23b to the midpoint of the linearly extending surface. For example, thin film 51 is disposed to a length of approximately 200 μm from the beginning of the linearly extending surface of portion 23b. This 200 μm length is a limitation imposed by deposition; if a film can be formed at or below this length by deposition or other methods, the length can be set to 200 μm or more.

[0039] Alternatively, the film 51 may be disposed from the beginning of the linearly extending surface of portion 23b to the middle of portion 23c, or to the end of portion 23c, or to the middle of portion 23d. Preferably, as described above, the film 51 may be disposed from the beginning of the linearly extending surface of portion 23b to the middle of the linearly extending surface. Alternatively, the film 51 may be disposed from the beginning of the linearly extending surface of portion 23b to the end. In other words, it may be disposed from the beginning of the linearly extending surface of portion 23b to the end of portion 23b.

[0040] The adhesion between the resin constituting the resin component 40 and the thin film 51 is worse than that between the copper constituting the conductive component 23 and the resin. Therefore, the smaller the area where the thin film 51 is disposed, the better. By disposing the thin film 51 from the beginning of the linearly extending surface of the portion 23b to the middle of the linearly extending surface, or to the end of the linearly extending surface, the contact area between the thin film 51 and the resin can be reduced, and the reduction in the adhesion between the conductive component 23 and the resin can be suppressed.

[0041] like Figure 2 As shown, the length of the thin film 51 in the Y direction is set to be equal to or less than the length of the portion 23b of the conductive component 23 in the Y direction.

[0042] The conductive component 23, as described above, contains, for example, copper.

[0043] Thin film 51 primarily comprises a material different from that of connecting member 32 and conductive member 23. Thin film 51 comprises a metal whose wettability to connecting member 32 is worse than that of copper; in other words, it comprises a metal that is less prone to wettability and spread to connecting member 32 compared to copper. Thin film 51, for example, primarily comprises nickel (Ni) or aluminum (Al). Thin film 51 comprising nickel or aluminum is formed, for example, by plating.

[0044] Additionally, thin film 51 may comprise a metal oxide film, such as copper oxide, nickel oxide, or aluminum oxide. The thickness of the metal oxide film is, for example, approximately 30 nm. Alternatively, thin film 51 may be an organic film, such as a solder resist.

[0045] Furthermore, when the thin film 51 is copper oxide and the conductive component 23 is copper, a copper oxide film is formed as a natural oxide film on the surface of the conductive component 23 that is not in contact with the thin film 51 or other components. The thin film 51 is distinguished from the natural oxide film described above. For example, the thickness of the natural oxide film is approximately 2 nm, while the thickness of the thin film 51 is approximately 30 nm. The thin film 51 is thicker than the natural oxide film. Furthermore, the oxygen density contained in the thin film 51 is also higher than the oxygen density contained in the natural oxide film.

[0046] The following is for reference Figure 5 The problems in the comparative example semiconductor device 100 will be explained, and then the effects of this embodiment will be explained. Figure 5 This is an enlarged cross-sectional view showing the connection structure between the semiconductor chip 10 and the conductive component 23 in the semiconductor device 100 of the comparative example.

[0047] In the comparative example semiconductor device 100, no thin film is provided on the lower surface of portion 23b of the conductive member 23. In the configuration described above, as... Figure 5 As shown, sometimes the connecting member 32 rises from the end of the region where the semiconductor chip 10 is connected to the portion 23a to the portion 23b, forming a large solder pad 32f for the connecting member 32. If the solder pad 32f is formed as described above, the amount of connecting member 32 will be insufficient, thereby sometimes forming a cavity between the semiconductor chip 10 and the conductive member 23 where the connecting member 32 is absent. In this case, the connection area between the semiconductor chip 10 and the conductive member 23 becomes insufficient, and the resistance value in the source electrode increases. Furthermore, the current supply to the semiconductor chip 10 decreases, resulting in the problem that the performance of the semiconductor chip 10 cannot be fully utilized.

[0048] Furthermore, if a cavity exists between the semiconductor chip 10 and the conductive component 23, some resin from the resin component may sometimes enter the cavity during the formation of the resin component 40. If resin enters the cavity, thermal stress caused by temperature changes due to the external environment and heat generated within the semiconductor device may increase the thermal stress on the front ends of the semiconductor chip 10 and the conductive component 23 where the resin has entered. This increased thermal stress may cause damage at the interface between the semiconductor chip 10 and the connecting component 32, and at the interface between the conductive component 23 and the connecting component 32.

[0049] In the semiconductor device 1 of this embodiment, a thin film 51 is provided on the lower surface of the portion 23b of the conductive member 23, that is, on the same surface as the surface on which the connecting member (e.g., solder) 32 is provided.

[0050] A thin film 51 is provided on portion 23b of the conductive component 23, thereby limiting the amount of climbing of the connecting component 32 to portion 23b and enabling control over the size of the solder joint formed at the end of portion 23a. The thin film 51 is a film with poorer wettability than the copper constituting the conductive component 23, thus preventing the connecting component 32 from climbing to portion 23b.

[0051] This reduces the likelihood of cavities forming between the semiconductor chip 10 and the conductive component 23. Consequently, the connection area between the semiconductor chip 10 and the conductive component 23 is sufficiently ensured, preventing an increase in resistance. Furthermore, it prevents a decrease in the current supplied to the semiconductor chip 10, allowing the semiconductor chip 10 to perform at its full potential.

[0052] Furthermore, it can reduce the formation of cavities, thus preventing resin from entering the cavities and suppressing the thermal stress applied to the front end of the semiconductor chip 10 and the conductive component 23.

[0053] Furthermore, in this embodiment, a thin film 51 is provided on the surface extending linearly from the beginning of the region extending linearly from the portion 23b of the conductive member 23 to the middle of the region extending linearly. However, the thin film 51 is not provided on the surface of the portion 23c of the conductive member 23. This reduces the contact area between the resin constituting the resin member 40 and the thin film 51. Since the adhesion between the thin film 51 and the resin is less than that between the copper constituting the conductive member 23 and the resin, reducing the contact area between the thin film 51 and the resin can suppress the decrease in adhesion between the conductive member 23 and the resin. This reduces peeling between the conductive member 23 and the resin, thereby improving the reliability of the semiconductor device.

[0054] Furthermore, if there are no problems with the adhesion between the conductive component 23 and the resin, a thin film 51 can be provided from the beginning of the linearly extending surface of portion 23b of the conductive component 23 to the end of the linearly extending surface. Also, a thin film 51 can be provided on the surface of portion 23c of the conductive component 23.

[0055] 2. Second Implementation Method

[0056] Next, the semiconductor device according to the second embodiment will be described. In the second embodiment, a thin film 51 is provided in a region extending linearly from the bend between portions 23a and 23b of the conductive member 23 to portion 23b. In the second embodiment, the differences from the first embodiment will be mainly described. Other structures not described are the same as those in the first embodiment.

[0057] Reference Figure 6 The connection structure between the semiconductor chip 10 and the conductive component 23 in the second embodiment will be described.Figure 6 yes Figure 3 The enlarged view of part A in the figure is a cross-sectional view showing the connection structure between the source electrode 10s of the semiconductor chip 10 and the conductive component 23.

[0058] A connecting member 32 is provided between the source electrode 10s of the semiconductor chip 10 and a portion 23a of the conductive member 23. A thin film 51 is provided on the lower surface of the portion 23b of the conductive member 23, that is, on the surface of the portion 23b in the X direction (or, -Z direction).

[0059] A curved portion (or curved portion) 23ab is provided between (or at the boundary) portions 23a and 23b of the conductive component 23. The curved portion 23ab is a region (or surface) that is curved between portions 23a and 23b.

[0060] Thin film 51 is disposed from the bend 23ab between portions 23a and 23b of conductive member 23 to the linearly extending surface (or region) of portion 23b. That is, thin film 51 is disposed on a portion of the bend 23ab between portions 23a and 23b and the linearly extending surface of portion 23b. Thin film 51 extends from the bend 23ab to the midway point of the linearly extending surface of portion 23b. Alternatively, thin film 51 may extend from the bend 23ab to the end of the linearly extending surface of portion 23b, i.e., to the position reaching portion 23c.

[0061] In the second embodiment, the thin film 51 is disposed on a portion of the curved portion 23ab between portions 23a and 23b, and on the straight-extending surface of portion 23b. Therefore, compared to the first embodiment, the amount of climbing of the connecting component (e.g., solder) 32 towards portion 23b can be limited, and the size of the solder joint formed at the end of portion 23a can be controlled. The other effects of the second embodiment are the same as those of the first embodiment.

[0062] 3. Third Implementation Method

[0063] Next, the semiconductor device according to the third embodiment will be described. In the third embodiment, the thin film 51 is provided only in the bent portion 23ab between portions 23b and 23c of the conductive member 23. In the third embodiment, the differences from the first embodiment will be mainly described. Other structures not described are the same as those in the first embodiment.

[0064] Reference Figure 7 The connection structure between the semiconductor chip 10 and the conductive component 23 in the third embodiment will be described. Figure 7 yes Figure 3The enlarged view of part A in the figure is a cross-sectional view showing the connection structure between the source electrode 10s of the semiconductor chip 10 and the conductive component 23.

[0065] The thin film 51 is disposed only on the surface of the curved portion 23ab between portions 23a and 23b of the conductive member 23, and is not disposed on the surface of portion 23b that extends in a straight line.

[0066] In the third embodiment, the range for the thin film 51 to be disposed is narrower than that in the first and second embodiments, but with the structure described above, it is also possible to limit the amount of climbing of the connecting component (e.g., solder) 32 and to control the size of the solder foot formed at the end of the portion 23a.

[0067] Furthermore, in the third embodiment, compared to the first and second embodiments, the contact area between the resin constituting the resin component 40 and the thin film 51 can be reduced. This further suppresses the decrease in the adhesion between the conductive component 23 and the resin. The other effects of the third embodiment are the same as those of the first embodiment.

[0068] Furthermore, in the aforementioned first to third embodiments, an example of a semiconductor device constituting a MOS-type field-effect transistor (i.e., MOSFET) was described. However, the semiconductor device can also be constituting other switching elements, such as an IGBT (insulated-gate bipolar transistor). When the semiconductor device is constituting an IGBT, the source corresponds to the emitter, and the drain corresponds to the collector.

[0069] Several embodiments of the present invention have been described, but these embodiments are given by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are equally included within the scope of the invention as set forth in the claims and its equivalents.

Claims

1. A semiconductor device, wherein, have: First conductive component; Second conductive component; A semiconductor chip is disposed between the first conductive component and the second conductive component; The first connecting component is disposed between the semiconductor chip and the second conductive component; as well as A thin film, disposed on the second conductive component, comprises a different material than that of the first connecting component. The second conductive component has a first plate portion, a second plate portion, and a third plate portion. The first plate extends along a first direction on a first surface of the semiconductor chip and is connected to the semiconductor chip via the first connecting member. The second plate portion extends obliquely from the first plate portion relative to the first direction. The third plate portion extends from the second plate portion in the first direction. The thin film is disposed on the surface of the second plate portion that is continuous with the surface on which the first connecting member is disposed.

2. The semiconductor device of claim 1, wherein, The film is in contact with the first connecting component.

3. The semiconductor device as claimed in claim 1, wherein, The second conductive component has a bent portion between the first plate portion and the second plate portion. The thin film is disposed on the surface of the curved portion.

4. The semiconductor device of claim 3, wherein, The curved portion is the area between the first plate portion and the second plate portion that is arranged in a curved shape.

5. The semiconductor device of claim 1, wherein, The second plate portion of the second conductive component has a surface extending in a straight line. The film is disposed on a surface that extends in the straight line.

6. The semiconductor device of claim 5, wherein, The film is positioned from the beginning of the surface extending in the straight line to the middle.

7. The semiconductor device of claim 5, wherein, The film is disposed from the beginning to the end of the surface that extends in the straight line.

8. The semiconductor device of claim 1, wherein, It also has: The third conductive component is disposed at a distance from the first conductive component; and Second connecting component, The second conductive component has a fourth plate portion. The fourth plate extends from the third plate in a second direction intersecting the first direction, and also extends in the first direction. The second connecting component is disposed between the third conductive component and the fourth plate.

9. The semiconductor device of claim 1, wherein, The thin film contains a different material than the second conductive component.

10. The semiconductor device of claim 1, wherein, The film contains either nickel or aluminum.

11. The semiconductor device of claim 1, wherein, The thin film comprises a metal oxide film.

12. The semiconductor device of claim 11, wherein, The metal oxide film comprises any one of copper oxide, nickel oxide, or aluminum oxide.

13. The semiconductor device of claim 1, wherein, The film comprises an organic film.

14. The semiconductor device of claim 1, wherein, The first connecting component includes solder.

15. The semiconductor device of claim 1, wherein, The second conductive component contains copper.

16. The semiconductor device of claim 1, wherein, The semiconductor chip includes a MOS-type field-effect transistor.

17. The semiconductor device of claim 1, wherein, The semiconductor chip includes an insulated gate bipolar transistor, i.e., an IGBT.

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