Semiconductor device

Abstract

To prevent a metal electrode from being destroyed by thermal stress in a semiconductor device in which a metal spacer and a semiconductor chip having metal electrodes are sinter-bonded.SOLUTION: A semiconductor device according to an embodiment includes a metal spacer, a semiconductor chip having a metal electrode, and a joint disposed between the metal spacer and the metal electrode. The joint is formed of a porous metal sintered body, and includes a first void formed in the metal spacer and not contained in the metal sintered body, and a second void contained in the metal sintered body, such that the Young's modulus of the joint is equal to or less than the Young's modulus of the metal spacer and the metal electrode.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] There is a method for joining components in which a metal sintered material for connection is formed in a predetermined printing pattern by printing in the connection areas of each component, the printing pattern consisting of areas where the metal sintered material is applied and areas where the metal sintered material is not applied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-079883 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is known a semiconductor device in which a metal spacer and a semiconductor chip having a metal electrode are sinter-bonded. In this type of semiconductor device, when the metal spacer and the semiconductor chip are sinter-bonded, the thermal expansion coefficient of the metal spacer differs from the thermal expansion coefficient of the semiconductor chip, which generates thermal stress and may cause deformation of the bonded portion and the metal electrode. In particular, when the Young's modulus of the bonded portion is larger than that of the metal electrode, thermal stress is concentrated on the metal electrode of the semiconductor chip, which may cause deformation and destruction, and therefore suppression of deformation of the metal electrode is an issue.

[0005] An embodiment of the present invention provides a semiconductor device that can suppress deformation of the metal electrodes of a semiconductor chip when thermal stress occurs, for a semiconductor chip having a metal spacer and a metal electrode connected via a metal sintered body. [Means for solving the problem]

[0006] According to an embodiment, a semiconductor device includes a metal spacer, a semiconductor chip having a metal electrode, and a joint formed between the metal spacer and the metal electrode. The joint is formed of a porous metal sintered body, and the metal sintered body includes a first void formed without being contained in the metal sintered body and a second void contained in the metal sintered body, so that the Young's modulus of the joint is equal to or lower than the Young's modulus of the metal spacer and the metal electrode. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of a structure of a semiconductor device. [Diagram 2] FIG. 4 is a top view showing an example of the shape of a first gap provided in a joint portion. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of the AA cross section of FIG. 2. [Figure 4] FIG. 4 is a diagram showing an example of an enlarged area W in FIGS. 2 and 3. [Diagram 5] FIG. 13 is a diagram showing an example of a range of porosity that can reduce thermal stress when the parent phase metal of the metal sintered material is silver and the metal electrode of the semiconductor chip is aluminum. [Figure 6] FIG. 13 is a diagram showing an example of the range of porosity that can suppress an increase in thermal resistance when the parent phase metal of the metal sintered material is silver and the metal electrode of the semiconductor chip is aluminum. [Figure 7] FIG. 13 is a diagram showing an example of a range in which thermal stress can be reduced and an increase in thermal resistance can be suppressed when the parent phase metal of the metal sintered material is silver and the metal electrodes of the semiconductor chip are aluminum. [Figure 8] FIG. 13 is a diagram showing an example of a range of porosity that can reduce thermal stress when the parent phase metal of the metal sintered material is copper and the metal electrode of the semiconductor chip is aluminum. [Figure 9] FIG. 13 is a diagram showing an example of the range of porosity that can suppress an increase in thermal resistance when the parent phase metal of the metal sintered material is copper and the metal electrodes of the semiconductor chip are aluminum. [Figure 10] FIG. 13 is a diagram showing an example of a range in which thermal stress can be reduced and an increase in thermal resistance can be suppressed when the parent phase metal of the metal sintered material is copper and the metal electrodes of the semiconductor chip are aluminum. [Figure 11] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 12] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 13] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 14] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 15] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 16] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 17] 13A and 13B are top views showing modified examples of the shape of the first gap in the joint portion. [Figure 18] FIG. 13 is a top view showing an example in which hexagonal first voids are arranged in a staggered pattern in a joint portion. [Figure 19] FIG. 13 is a top view showing an example of a case where circular joints are formed in a staggered pattern. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 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 those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. 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.

[0009] (First embodiment) FIG. 1 is a cross-sectional view showing an example of the configuration of a semiconductor device 1. As shown in FIG. 1, in the semiconductor device 1, a metal electrode portion 12a, a joint portion 13a, and a metal spacer 14a are provided in this order on the upper side of a semiconductor chip 11. In addition, a metal electrode portion 12b, a joint portion 13b, and a metal spacer 14b are provided in this order on the lower side of the semiconductor chip 11. The metal electrode portions 12a, 12b, the joint portions 13a, 13b, and the metal spacers 14a, 14b are each made of the same material.

[0010] In the semiconductor device 1, the metal electrode portions 12a, 12b and the metal spacers 14a, 14b are sinter-bonded via the bonding portions 13a, 13b, respectively.

[0011] The material of the semiconductor chip 11 is, for example, silicon (Si). The thermal expansion coefficient of the semiconductor chip 11 is, for example, 2.6×10 -6 [ / K]. The material of the metal electrode portions 12a, 12b is, for example, aluminum (Al). In this embodiment, aluminum is used as an example, but an aluminum alloy containing aluminum may also be used. The metal electrode portions 12a, 12b may be configured to be connected to the semiconductor chip 11 via nickel-gold or nickel-silver. The thermal expansion coefficient of the metal electrode portions 12a, 12b is, for example, 23.9×0 -6 [ / K]. The joints 13a, 13b are porous sintered metal bodies arranged between the metal electrode parts 12a, 12b and the metal spacers 14a, 14b. In this embodiment, the metal type of the sintered metal body forming the joints 13a, 13b is, for example, silver (Ag), and its thermal expansion coefficient is 19.7×10 -6 [ / K]. The material of the metal spacers 14a and 14b is, for example, molybdenum (Mo). The thermal expansion coefficient of the metal spacers 14a and 14b is 4.8×10 -6 [ / K].

[0012] Fig. 2 is a top view showing an example of the shape of the bonding portion 13a formed on the metal spacer 14a. Fig. 3 is a cross-sectional view showing an example of the AA cross section of Fig. 2. In this embodiment, the semiconductor device 1 has a rectangular shape when viewed from above. Region W indicates a partial region of the bonding portion 13a.

[0013] As shown in FIG. 2 and FIG. 3, the joint 13a is disposed on the metal spacer 14a. The joint 13a has a plurality of first voids G1 in a top view. In this embodiment, the first voids G1 are, for example, circular in a top view. The first voids G1 are formed between the metal electrode parts 12a, 12b and the metal spacers 14a, 14b. The radius of the first voids G1 is, for example, a radius r1. The plurality of first voids are disposed at intervals R. In the even-numbered columns and the odd-numbered columns, the intervals between the plurality of first voids are shifted by R / 2 (half). In the even-numbered rows and the odd-numbered rows, the interval between the plurality of first voids is the diameter R of G1. In this way, the first voids G1 are disposed in a staggered pattern in the joint 13a in a top view.

[0014] FIG. 4 is a diagram showing an example in which the region W in FIG. 2 and FIG. 3 is enlarged. As shown in FIG. 4, a plurality of second voids G2 are provided. The second voids G2 are voids contained within the joint portion 13a. The ratio of the second voids G2 within the joint portion 13a is determined, for example, by the material of the joint portion 13a, its shape and dimensions, and the process during sinter bonding. The second voids G2 are very small voids compared to the first voids G1. In other words, the first voids G1 are macro voids, and the second voids G2 are micro voids. The first voids G1 are, for example, circular holes with a diameter of 0.1 mm or more in top view, and the second voids G2 are, for example, spaces with a diameter of about 1 to 10 μm. The second voids G2 are generated in the joint portion 13a in a scattered manner during the sinter bonding process. Like the region W, the joint portion 13b and the portion of the joint portion 13a other than the region W also include the second gap G2 during sinter bonding.

[0015] Next, a method for suppressing deformation of the metal electrode portions 12a and 12b due to thermal stress occurring between the semiconductor chip 11 and the metal spacers 14a and 14b in the semiconductor device 1 will be described. In the semiconductor device 1, in order to reduce thermal stress occurring in the metal electrode portions 12a and 12b, the Young's modulus of the bonding portions 13a and 13b is set to be equal to or lower than the Young's modulus of the metal electrode portions 12a and 12b. Here, Young's modulus is E=σ / ε (E: Young's modulus, σ: stress, ε: strain). In this embodiment, since the metal electrode portions 12a and 12b are made of aluminum, the Young's modulus of the bonding portions 13a and 13b is set to be equal to or lower than the Young's modulus of aluminum. To achieve this, the above-mentioned multiple first voids G1 and multiple second voids G2 are provided in the bonding portions 13a and 13b.

[0016] 5 is a diagram showing an example of a range of porosity capable of reducing thermal stress occurring in the metal electrode portions 12a and 12b. The vertical axis shows the second porosity y indicating the proportion of the second voids G2 in the bonding portions 13a and 13b, and the horizontal axis shows the first porosity x indicating the proportion of the first voids G1 in the bonding portions 13a and 13b. Here, E W is defined as the Young's modulus of a region W that is a part of the joints 13a and 13b that does not include the first gap G1 and includes only the second gap G2, E Ag is the Young's modulus of silver, E 接合部 is the Young's modulus of the joints 13a and 13b, E Al is the Young's modulus of aluminum, then E 接合部 ≦E Al The range in which the above formula (1) and formula (2) are satisfied is the case where the following formula (1) and formula (2) are satisfied. The Young's modulus of the region other than the region W, which does not include the first gap G1 and includes only the second gap G2, is E W is the same as: E W =E Ag (1-y) …(1) E 接合部 =E W (1-x)=E Ag (1-x)(1-y) …(2)

[0017] The range that satisfies formulas (1) and (2) is the region AR1 in FIG. 5. The region AR1 is the upper region of the figure that connects positions P11 (15,0), P12 (15,4), P13 (4,15), and P14 (0,15). The first gap G1 and the second gap G2 are provided in the joints 13a and 13b so that the first porosity x and the second porosity y are within the region AR1, and thus the Young's modulus of the joints 13a and 13b is equal to or less than the Young's modulus of aluminum (metal electrode portions 12a and 12b). Therefore, the thermal stress generated in the metal electrode portions 12a and 12b is reduced, and deformation is suppressed.

[0018] Next, a method for suppressing an increase in thermal resistance caused by providing a gap at the bonding portions 13a and 13b of the semiconductor device 1 will be described. In the semiconductor device 1, in order to suppress the thermal resistance of the joints 13a, 13b, the thermal conductivity of the joints 13a, 13b is set to a predetermined value or less. For example, in this embodiment, the thermal conductivity of the joints 13a, 13b is set to 200 W / mK or more. A thermal conductivity of 200 W / mK is about four times that of solder. However, the value of the thermal conductivity is not limited to this.

[0019] Fig. 6 is a diagram showing an example of a range of porosity that can suppress an increase in the thermal resistance of the joints 13a and 13b. Regarding the increase in the thermal resistance of the joints 13a and 13b due to the introduction of voids, it is desirable to specify the ratio of voids within a range in which the apparent thermal conductivity of the joints 13a and 13b including the voids does not decrease significantly. As in the case of Fig. 5, the vertical axis shows the second porosity y indicating the ratio of the second voids G2 in the joints 13a and 13b, and the horizontal axis shows the first porosity x indicating the ratio of the first voids G1 in the joints 13a and 13b. Here, λ W is the thermal conductivity of a region W that is a part of the joints 13a, 13b that does not include the first gap G1 and includes only the second gap G2, λ Ag is the thermal conductivity of silver, λ 接合部 is the thermal conductivity of the joints 13a and 13b, λ 接合部 The range that satisfies ≧200 W / mK is the range that satisfies the following formulas (3) and (4). Note that the thermal conductivity of the region that does not include the first gap G1 other than the region W and includes only the second gap G2 is λW is the same as: λ W = λ Ag (1-y) …(3) λ 接合部 = λ W (1-x)=λ Ag (1-x)(1-y) …(4)

[0020] The range that satisfies formulas (3) and (4) is region AR2 in Fig. 6. Region AR2 is the region below the figure that connects position P21 (52,0), position P22 (52,15), position P23 (15,52), and position P24 (0,52). By providing first gap G1 and second gap G2 in joints 13a and 13b so that first porosity x and second porosity y are within region AR2, the thermal conductivity of joints 13a and 13b becomes 200 W / mK or more, and an increase in the thermal resistance of joints 13a and 13b is suppressed.

[0021] Fig. 7 is a diagram showing an example of a range of porosity capable of reducing thermal stress generated in the metal electrode portions 12a and 12b and suppressing an increase in the thermal resistance of the joint portions 13a and 13b. In other words, Fig. 7 is a combination of Figs. 5 and 6. 7, the range of porosity that can reduce thermal stress and suppress an increase in thermal resistance is region AR3. Region AR3 is the region surrounded by position P11 (15,0), position P12 (15,4), position P13 (4,15), position P14 (0,15), position P21 (52,0), position P22 (52,15), position P23 (15,52), and position P24 (0,52).

[0022] Next, the process of forming the joints 13a, 13b will be described. The method of forming the metal sintered material on the metal spacers 14a, 14b may be, for example, by applying the metal sintered material to the metal spacers 14a, 14b by squeegee printing. Squeegee printing is a printing method in which a screen plate is pressed against the metal spacers 14a, 14b, and the paste-like metal sintered material applied to the screen plate is scraped off. In addition, the metal sintered material may be supplied by, for example, a jet dispenser. Furthermore, for example, a sheet-like metal sintered material may be transferred onto the metal spacers 14a, 14b. In this case, a first gap G1 is provided in advance in the sheet-like metal sintered material.

[0023] Next, the metal electrode parts 12a, 12b and the metal spacers 14a, 14b are sinter-bonded. In this sinter-bonding process, the bonding parts 13a, 13b are formed. With the formation of the bonding parts 13a, 13b, the first gap G1 and the second gap G2 appear in the proportion of the area AR3 shown in FIG. 7. As a result, the Young's modulus of the bonding parts 13a, 13b becomes equal to or smaller than that of the metal electrode parts 12a, 12b and the metal spacers 14a, 14b. Therefore, it is possible to suppress the deformation of the metal electrode parts 12a, 12b due to the reduction in thermal stress generated in the metal electrode parts 12a, 12b, and the increase in the thermal resistance of the bonding parts 13a, 13b.

[0024] Second embodiment The second embodiment is different from the first embodiment in that copper (Cu) is used as the metal type of the metal sintered body forming the joints 13a and 13b. The difference due to the use of copper as the material of the joints 13a and 13b will be described in detail below. Note that the same reference numerals are used for the same components as those in the first embodiment, and detailed description of these components will be omitted.

[0025] 8 is a diagram showing an example of a range of porosity capable of reducing thermal stress occurring in the metal electrode portions 12a and 12b. The vertical axis shows the second porosity y indicating the proportion of the second voids G2 in the bonding portions 13a and 13b, and the horizontal axis shows the first porosity x indicating the proportion of the first voids G1 in the bonding portions 13a and 13b. Here, E Wis defined as the Young's modulus of a region W that is a part of the joints 13a and 13b that does not include the first gap G1 and includes only the second gap G2, E Cu is the Young's modulus of copper, E 接合部 is the Young's modulus of the joints 13a and 13b, E Al is the Young's modulus of aluminum, then E 接合部 ≦E Al The range in which the above formula (5) and formula (6) are satisfied is the case where the following formula (5) and formula (6) are satisfied. The Young's modulus of the region other than the region W that does not include the first gap G1 and includes only the second gap G2 is E W is the same as: E W =E Cu (1-y) …(5) E 接合部 =E W (1-x)=E Cu (1-x)(1-y) …(6)

[0026] The range that satisfies formulas (5) and (6) is the region AR4 in FIG. 8. The region AR4 is the region above the figure L11 that connects the position P31 (46,0) and the position P32 (0,46). By providing the first gap G1 and the second gap G2 in the joints 13a and 13b so that the first porosity x and the second porosity y are within the region AR4, the Young's modulus of the joints 13a and 13b is equal to or less than the Young's modulus of aluminum (metal electrode portions 12a and 12b). Therefore, the thermal stress generated in the metal electrode portions 12a and 12b is reduced, and deformation is suppressed.

[0027] Fig. 9 is a diagram showing an example of a range of porosity capable of suppressing an increase in the thermal resistance of the bonding parts 13a and 13b. The vertical axis shows the second porosity y indicating the proportion of the second gaps G2 in the bonding parts 13a and 13b, and the horizontal axis shows the first porosity x indicating the proportion of the first gaps G1 in the bonding parts 13a and 13b, as in the case of Fig. 8. Here, λ W is the thermal conductivity of a region W that is a part of the joints 13a, 13b that does not include the first gap G1 and includes only the second gap G2, λ Cu is the thermal conductivity of copper, λ 接合部 is the thermal conductivity of the joints 13a and 13b, λ 接合部9, which satisfies the following formulas (7) and (8): Note that the same applies to a region other than the region W that does not include the first gap G1 and includes only the second gap G2. λ W = λ Cu (1-y) …(7) λ 接合部 = λ W (1-x)=λ Cu (1-x)(1-y) …(8)

[0028] The range that satisfies formulas (7) and (8) is region AR5 in the figure. Region AR5 is the region below figure L12 that connects position P41 (49,0) and position P42 (0,49). By providing first gap G1 and second gap G2 in joints 13a and 13b so that first porosity x and second porosity y are within region AR5, the thermal conductivity of joints 13a and 13b becomes 200 W / mK or more, and an increase in thermal resistance is suppressed.

[0029] Fig. 10 is a diagram showing an example of a range of porosity capable of reducing thermal stress generated in the metal electrode portions 12a and 12b and suppressing an increase in the thermal resistance of the joint portions 13a and 13b. In other words, Fig. 10 is a combination of Figs. 8 and 9. 10, the range of porosity that can reduce thermal stress and suppress an increase in thermal resistance is region AR6. Region AR6 is a region surrounded by curve L11 connecting position P31 (46,0) and position P32 (0,46), and curve L12 connecting position P41 (49,0) and position P42 (0,49).

[0030] By providing the first gap G1 and the second gap G2 in the joints 13a and 13b so that the first porosity x and the second porosity y are within the region AR6, the Young's modulus of the joints 13a and 13b is equal to or less than that of the metal electrode parts 12a and 12b and the metal spacers 14a and 14b. Therefore, it is possible to suppress the deformation of the metal electrode parts 12a and 12b due to the reduction in thermal stress generated in the metal electrode parts 12a and 12b, and the increase in the thermal resistance of the joints 13a and 13b. In this way, even when copper is used as the material for the joints 13a and 13b, it is possible to achieve the same effect as the first embodiment.

[0031] (Modification) Next, modified examples of the bonding portions 13a and 13b formed on the metal spacers 14a and 14b will be described. 11 to 13 are top views showing modified shapes of the first gaps of the joints 13a and 13b. In Fig. 11 to 13, a sheet-shaped metal sintered material is transferred to metal spacers 14a and 14b, which are then sinter-bonded to the metal electrode parts 12a and 12b to form the joints 13a and 13b. The joints 13a and 13b have the same configuration, so the joint 13a will be described as an example.

[0032] 11 is a top view showing a case where the radius of the first gap is changed. The radius of the first gap G11 formed at the end A1 and the central portion A2 of the metal spacer 14a, and the radius of the first gap G12 formed at the intermediate portion A3 formed between the end A1 and the central portion A2 are changed. The end A1 and the central portion A2 are areas where stress and heat are more likely to concentrate than the intermediate portion A3. In this embodiment, the first gap G11 is smaller than the first gap G12. In other words, the size of the first gap G12 is larger than that of the first gap G11.

[0033] Fig. 12 is a top view showing a case where the radius of the first gaps G1 in the joint 13a is the same but the distribution is changed. As shown in Fig. 12, a first distribution of the first gaps G1 formed in the end portion A1 and the central portion A2 is different from a second distribution of the first gaps G1 formed in the intermediate portion A3 formed between the end portion A1 and the central portion A2. The end portion A1 and the central portion A2 are regions where stress and heat are more likely to concentrate than the intermediate portion A3. In this embodiment, the first distribution of the end portion A1 and the central portion A2 is sparser than the second distribution of the intermediate portion A3, and the proportion of the first gaps G1 is reduced.

[0034] FIG. 13 is a top view showing a case where the radius of the first gap is changed for each of the first and second distributions in addition to having the first and second distributions shown in FIG. 12. In this embodiment, the radius of the first gap G11 formed at the end A1 and the center A2 is different from that of the first gap G12 formed at the intermediate portion A3. The end A1 and the center A2 are areas where stress and heat are more likely to concentrate than the intermediate portion A3. The size of the first gap G11 in the first distribution is made smaller than the first gap G12 in the second distribution. In other words, the size of the first gap G11 at the end A1 and the center A2 where stress and heat are more likely to concentrate is smaller than the size of the first gap G12.

[0035] 14 to 17 are top views showing modified shapes of the first gaps of the joints 13a and 13b. In Fig. 14 to 17, a paste-like metal sintering material is applied to metal spacers 14a and 14b, which are then sinter-bonded to the metal electrode parts 12a and 12b to form the joints 13a and 13b. Since the joints 13a and 13b are similar, the joints 13a and the metal spacer 14a will be described as an example.

[0036] Fig. 14 is a top view showing an example in which the first gaps are arranged in a staggered pattern. In Fig. 14, the number of first gaps G1 is different from that of the example of the joint 13a shown in Fig. 2. Since a paste-like sintered member is used, lines L31 are formed that connect the first gaps G1 of each row in the horizontal direction shown in the figure. Figs. 15 to 17 correspond to Figs. 11 to 13 described above, respectively. In Figs. 15 to 17, lines L32, L33, and L34 are also provided that connect the first gaps G1 (G11, G12) of each row in the horizontal direction shown in the figure.

[0037] In the above embodiment, the shape of the first gap G1 in top view is described as being circular, but the shape is not limited thereto. For example, the shape of the first gap G1 in top view may be polygonal. The polygonal shape may be, for example, a triangular shape, a rectangular shape, a hexagonal shape, etc., and the more corners there are, the more preferable the shape is. FIG. 18 is a top view showing an example in which the hexagonal first gap G13 is arranged in a staggered pattern in the joint 13a.

[0038] As shown in Figures 11 to 18, by forming the joints 13a and 13b, the first gap G1 (or G11, G12, G13) and the second gap G2 of the joints 13a and 13b can reduce the thermal stress generated in the metal electrode portions 12a and 12b in the semiconductor device 1 and suppress an increase in the thermal resistance of the joints 13a and 13b.

[0039] In addition, in the joints 13a, 13b shown in Figs. 11 to 18, the first gap G1 and the metal sintered material may be reversed. That is, a joint is provided in the first gap G1, and the other parts are voids. Fig. 19 is a top view showing an example of the joints 13a, 13b made of a plurality of circular metal sintered bodies 13a1 arranged in a staggered pattern. In this way, the first gap G1 (region outside the metal sintered bodies 13a1) and the second gap G2 are formed in the joints 13a, 13b by the plurality of metal sintered bodies 13a1, and it is possible to reduce the thermal stress generated in the metal electrode parts 12a, 12b and suppress the increase in the thermal resistance of the joints 13a, 13b. Even when the joints 13a, 13b are formed in this way, the same effects as those of the first embodiment can be achieved.

[0040] In the first embodiment, silver is used as the material of the joints 13a and 13b, and in the second embodiment, copper is used as the material of the joints 13a and 13b, but the material of the joints 13a and 13b is not limited to these. For example, gold (Au), nickel (Ni), aluminum (Al), and platinum (Pt) may be used. In other words, the material of the joints 13a and 13b may contain any of silver, copper, gold, nickel, aluminum, and platinum.

[0041] Furthermore, the Young's modulus differs depending on the type of metal. Therefore, when a metal having a higher Young's modulus than silver is used for the bonding portions 13a and 13b, the ratio of the first gap G1 and the second gap G2 becomes larger than that in the case of silver. When a metal having a lower Young's modulus than silver is used for the bonding portions 13a and 13b, the ratio of the first gap G1 and the second gap G2 becomes smaller than that in the case of silver.

[0042] Although several embodiments of the present invention have been described above, 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 gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. In addition, the above-mentioned embodiments can be implemented in combination with each other.

[0043] The embodiments include the following aspects.

[0044] (Appendix 1) A metal spacer; A semiconductor chip having a metal electrode; a joint disposed between the metal spacer and the metal electrode; Equipped with the joint is formed of a porous metal sintered body, The metal sintered body includes a first void formed without being contained in the metal sintered body, and a second void contained in the metal sintered body, The Young's modulus of the joint is lower than the Young's modulus of each of the metal spacer and the metal electrode. Semiconductor device.

[0045] (Appendix 2) The Young's modulus of the joint is determined by the Young's modulus of a metal bulk forming the metal sintered body and the ratio of the first voids and the second voids. 2. The semiconductor device according to claim 1.

[0046] (Appendix 3) The ratio x of the first voids and the ratio y of the second voids satisfy the following formula, E 接合部 =E 金属 (1-x)(1-y)≦E 電極 The above E 接合部 is the Young's modulus of the joint, The above E金属 is the Young's modulus of the metal bulk forming the metal sintered body, The above E 電極 is the Young's modulus of the metal electrode; 3. The semiconductor device according to claim 1 or 2.

[0047] (Appendix 4) The thermal conductivity of the joint is higher than 200 W / mK and is determined by the thermal conductivity of the metal forming the metal sintered body and the ratio of the first voids and the second voids. 4. The semiconductor device according to claim 1, wherein the first and second electrodes are arranged in a first direction.

[0048] (Appendix 5) The ratio x of the first voids and the ratio y of the second voids satisfy the following formula, λ 接合部 = λ 金属 (1-x)(1-y)≧200 Said λ 接合部 is the thermal conductivity of the joint, Said λ 金属 is the thermal conductivity of the metal bulk forming the metal sintered material; 5. The semiconductor device according to claim 1,

[0049] (Appendix 6) The first voids are arranged in a staggered pattern in the joint portion, Furthermore, in the joint, the ratio of the first voids is reduced in an area where stress and heat are concentrated. 6. The semiconductor device according to claim 1,

[0050] (Appendix 7) The first gap is circular or polygonal in top view. 7. The semiconductor device according to claim 1,

[0051] (Appendix 8) In the joint, the size of the first gap is reduced in an area where stress and heat are concentrated. 8. The semiconductor device according to claim 1,

[0052] (Appendix 9) The joint contains any one of metals selected from Ag, Cu, Au, Ni, Al, and Pt. 9. The semiconductor device according to any one of claims 1 to 8. [Explanation of symbols]

[0053] 1...semiconductor device, 11...semiconductor chip, 12a, 12b...metal electrode portion, 13a, 13b, 13a1...joint portion, 14a, 14b...metal spacer, A1...end portion, A2...center portion, A3...middle portion, G1, G11, G12, G13...first gap, G2...second gap, x...first porosity, y...second porosity, W...area

Claims

1. A metal spacer; A semiconductor chip having a metal electrode; a joint disposed between the metal spacer and the metal electrode; Equipped with the joint is formed of a porous metal sintered body, The metal sintered body includes a first void formed without being contained in the metal sintered body, and a second void contained in the metal sintered body, the Young's modulus of the joint is lower than the Young's modulus of each of the metal spacer and the metal electrode; Semiconductor device.

2. The Young's modulus of the joint is determined by the Young's modulus of a metal bulk forming the metal sintered body and a ratio of the first voids and the second voids. The semiconductor device according to claim 1 .

3. The ratio x of the first voids and the ratio y of the second voids satisfy the following formula: E 接合部 =E 金属 (1-x)(1-y)≦E 電極 The above E 接合部 is the Young's modulus of the joint, The above E 金属 is the Young's modulus of the metal bulk forming the metal sintered body, The above E 電極 is the Young's modulus of the metal electrode; The semiconductor device according to claim 1 .

4. The thermal conductivity of the joint is higher than 200 W / mK and is determined by the thermal conductivity of the metal forming the metal sintered body and the ratio of the first void and the second void. The semiconductor device according to claim 1 .

5. The ratio x of the first voids and the ratio y of the second voids satisfy the following formula, l 接合部 =λ 金属 (1-x)(1-y)≧200 Said λ 接合部 is the thermal conductivity of the joint, Said λ 金属 is the thermal conductivity of the metal bulk forming the metal sintered body; The semiconductor device according to claim 1 .

6. The first gaps are arranged in a staggered pattern in the joint portion, Furthermore, in the joint, the ratio of the first voids is reduced in a region where stress and heat are concentrated. The semiconductor device according to claim 1 .

7. The first gap is circular or polygonal in top view. The semiconductor device according to claim 1 .

8. In the joint, the size of the first gap is reduced in an area where stress and heat are concentrated. The semiconductor device according to claim 1 .

9. The joint contains any one of metals selected from Ag, Cu, Au, Ni, Al, and Pt. The semiconductor device according to claim 1 .

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