Semiconductor device and manufacturing method of the same

Abstract

To define a thickness of each sinter layer accurately in a semiconductor device in which the sinter layers are formed on both surfaces of a semiconductor element by sintered members.SOLUTION: A semiconductor device 100 includes: a semiconductor element 101 which has an upper surface and a lower surface and in which an upper surface electrode is formed on the upper surface and a lower surface electrode is formed on the lower surface; a source lead member 102 which is a conductor electrically connected to the upper surface electrode of the semiconductor element 101; a drain lead member 103 which is a conductor electrically connected to the lower surface electrode of the semiconductor element 101; a sinter joint layer 104 which is formed of a conductive sintered body and joins the upper surface electrode of the semiconductor element 101 and the source lead member 102 to each other; a sinter joint layer 105 which is formed of a conductive sintered body and joins the lower surface electrode of the semiconductor element 101 and the drain lead member 103 to each other; and a stopper 106 which is disposed between the upper surface of the semiconductor element 101 and the source lead member 102.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a semiconductor device and a manufacturing method thereof. [Background technology]

[0002] Power conversion devices that convert DC power and AC power mutually by the switching operation of semiconductor elements have high conversion efficiency and are therefore widely used in consumer applications, vehicle-mounted applications, railway applications, substation equipment, etc. Since semiconductor elements generate heat due to their switching operation, semiconductor devices in which semiconductor elements are encapsulated are required to have high heat dissipation properties.

[0003] Patent Document 1 discloses a semiconductor device that includes a semiconductor element having a source electrode on one side and a drain electrode on the other side, and a conductive spacer that constitutes a wiring member, in which the source electrode and the conductive spacer are bonded with a bonding material, and the drain electrode and a surface metal body of a substrate are bonded with a bonding material. It is also disclosed that in this semiconductor device, a sintered material (sinter) such as sintered silver may be used as the bonding material instead of general solder.

[0004] In the semiconductor device described in Patent Document 1, when sinter is used as the bonding material, it can generally be manufactured by the following manufacturing process. That is, in a state where a conductive spacer and a substrate are arranged on both sides of a semiconductor element via uncured sinter, the conductive spacer and the substrate are pressed in the direction in which the semiconductor element is sandwiched to thinly crush the sinter, forming a sinter layer between the semiconductor element and the conductive spacer and between the semiconductor element and the substrate, and making the entire semiconductor device a desired thickness. By hardening the sinter layer in this state, the source electrode and drain electrode of the semiconductor element are bonded to the conductive spacer and the surface metal body of the substrate via the sinter layer, respectively, and a semiconductor device having a desired thickness is formed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2022-181814 Summary of the Invention [Problem to be solved by the invention]

[0006] In the manufacturing process of the semiconductor device as described above, the thickness of the sinter layer formed on each side of the semiconductor element varies depending on the pressure applied. However, in the structure of the semiconductor device described in Patent Document 1, the semiconductor element is not fixed when pressure is applied, so it is difficult to arbitrarily control the pressure applied to each side of the semiconductor element, and the thickness of the sinter layer cannot be precisely specified.

[0007] The thickness of the sinter layer formed between the semiconductor element and the conductive spacer or substrate to bond them has a large effect on the properties such as bonding strength, durability, and heat dissipation of the semiconductor element. In other words, if the sinter layer is too thin, the necessary bonding strength and durability cannot be obtained, while if it is too thick, the semiconductor element cannot dissipate heat sufficiently. Therefore, in order to obtain the desired properties in the semiconductor device, it is preferable to precisely specify the thickness of the sinter layer, but as described above, this is difficult with the structure of conventional semiconductor devices.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its main object is to accurately specify the thickness of each sinter layer in a semiconductor device in which sinter layers made of sintered materials are formed on both sides of a semiconductor element. [Means for solving the problem]

[0009] A semiconductor device according to the present invention comprises a semiconductor element having an upper surface and a lower surface, with an upper surface electrode formed on the upper surface and a lower surface electrode formed on the lower surface, a first conductor electrically connected to the upper surface electrode, a second conductor electrically connected to the lower surface electrode, a first sintered bonding layer made of a conductive sintered body and bonding the upper surface electrode and the first conductor, a second sintered bonding layer made of a conductive sintered body and bonding the lower surface electrode and the second conductor, and a stopper arranged between the upper surface and the first conductor, wherein the area of ​​the surface of the second sintered bonding layer in contact with the lower surface is larger than the area of ​​the surface of the first sintered bonding layer in contact with the upper surface, and the stopper has a lower end abutting the semiconductor element and an upper end abutting the first conductor. A method for manufacturing a semiconductor device according to a first aspect of the present invention includes placing a sintering paste on a second conductor, placing a semiconductor element having an upper surface on which an upper electrode is formed and a lower surface on which a lower electrode is formed, on the sintering paste placed on the second conductor so that at least a portion of the lower electrode is in contact with the sintering paste, placing a first conductor on which the sintering paste is placed and on which a stopper is formed around the sintering paste, above the semiconductor element with the sintering paste and the stopper facing the upper surface side, and removing the sintering paste placed on the first conductor from the front side. By contacting the stopper with the upper surface, a circuit body is formed in which the first conductor, the semiconductor element, and the second conductor overlap each other via the sintering paste, and the stopper abuts the upper surface, and pressure is applied to the circuit body in a direction in which the first conductor and the second conductor approach each other until the thickness of the sintering paste placed on the second conductor reaches a specified value, thereby sintering the sintering paste and performing a sintering process to form a first sintered bonding layer that bonds the upper electrode and the first conductor and a second sintered bonding layer that bonds the lower electrode and the second conductor, and then sealing the circuit body after the sintering process. A method for manufacturing a semiconductor device according to a second aspect of the present invention includes placing a sintering paste on a second conductor, placing a semiconductor element having an upper surface on which an upper electrode is formed and a lower surface on which a lower electrode is formed on the sintering paste on the second conductor such that at least a portion of the lower electrode is in contact with the sintering paste, further placing the sintering paste on the upper surface of the semiconductor element placed on the sintering paste, placing a first conductor having a stopper formed at a position outside the sintering paste placed on the upper surface above the semiconductor element with the stopper facing the upper surface side, By bringing the sintering paste into contact with the first conductor, a circuit body is formed in which the first conductor, the semiconductor element, and the second conductor overlap each other via the sintering paste, the stopper abuts the upper surface, and pressure is applied to the circuit body in a direction in which the first conductor and the second conductor approach each other until the thickness of the sintering paste placed on the second conductor reaches a specified value, the sintering paste is sintered, and a sintering process is performed to form a first sintered bonding layer that bonds the upper electrode and the first conductor and a second sintered bonding layer that bonds the lower electrode and the second conductor, and the circuit body after the sintering process is sealed. Effect of the Invention

[0010] According to the present invention, in a semiconductor device in which sintered layers made of sintered members are formed on both sides of a semiconductor element, the thickness of each sintered layer can be precisely defined. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view of a circuit body from which a sealing material has been removed, according to a first embodiment of the present invention. [Diagram 3] 11A and 11B are diagrams illustrating examples of arrangement of stoppers. [Figure 4] 1A to 1C are diagrams illustrating an example of a manufacturing process of a semiconductor device. [Diagram 5] 11A to 11C are diagrams illustrating another example of a manufacturing process of a semiconductor device. [Figure 6] FIG. 4 is a diagram showing a configuration of a semiconductor device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0013] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0014] (First embodiment) Fig. 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention. The semiconductor device 100 shown in Fig. 1 includes a semiconductor element 101, a source lead member 102, a drain lead member 103, sintered junction layers 104 and 105, and a stopper 106. The semiconductor device 100 has a structure in which these members are sealed with a non-conductive sealing material 110. The sealing material 110 may be, for example, a resin.

[0015] The semiconductor element 101 is a semiconductor chip such as a MOSFET whose main material is, for example, Si or SiC. The semiconductor element 101 is used, for example, as a switching element of an inverter, and has an upper surface on the source lead member 102 side and a lower surface on the drain lead member 103 side. An upper surface electrode (source electrode) electrically connected to the source lead member 102 is provided on the upper surface of the semiconductor element 101, and a lower surface electrode (drain electrode) electrically connected to the drain lead member 103 is provided on the lower surface of the semiconductor element 101. In this way, by configuring the semiconductor device 100 using the semiconductor element 101 having electrodes on both the upper and lower surfaces, the semiconductor device 100 can be made smaller.

[0016] The source lead member 102 and the drain lead member 103 are both conductors and are formed using a conductive material such as copper. The source lead member 102 is electrically connected to the upper electrode of the semiconductor element 101, and the drain lead member 103 is electrically connected to the lower electrode of the semiconductor element 101. A source terminal (not shown) is connected to the source lead member 102, and drain terminals 103a and 103b protruding from the resin 110 are provided on the drain lead member 103. In the switching operation of the semiconductor element 101, the flow of current supplied from a power source (not shown) through these terminals is controlled by switching the conduction state between the source electrode and the drain electrode. The source terminal may be formed by exposing a part of the source lead member 102 from the sealing material 110, or the drain lead member 103 and the drain terminals 103a and 103b may be configured as separate members.

[0017] The sintered junction layer 104 is formed between the source lead member 102 and the upper electrode of the semiconductor element 101, and bonds them together. The sintered junction layer 105 is formed between the drain lead member 103 and the lower electrode of the semiconductor element 101, and bonds them together. The sintered junction layers 104 and 105 are made of a sintered body of a conductive material such as silver or copper, and are known to have high reliability and thermal conductivity compared to solder, which is often commonly used as a conductive bonding material.

[0018] The sintered junction layers 104 and 105 are formed in the manufacturing process of the semiconductor device 100 by compressing a sintering paste, which is a flexible conductive paste material, to thin it, and then heating it to a predetermined sintering temperature to sinter it. As shown in FIG. 1, the sintered junction layer 104 formed on the upper surface side of the semiconductor element 101 has a smaller bonding area than the sintered junction layer 105 formed on the lower surface side of the semiconductor element 101. That is, the area of ​​the surface of the sintered junction layer 105 that contacts the lower surface of the semiconductor element 101 is larger than the area of ​​the surface of the sintered junction layer 104 that contacts the upper surface of the semiconductor element 101. This makes it easier for a pressure force to be applied to the sintered junction layer 104 when pressure is applied. Details of the method of forming the sintered junction layers 104 and 105 in the manufacturing process of the semiconductor device 100 will be described later.

[0019] The stopper 106 is disposed between the upper surface of the semiconductor element 101 and the source lead member 102. When the sintering paste is compressed to form the sintered junction layers 104, 105 as described above, the stopper 106 plays a role in ensuring a certain distance between the upper surface of the semiconductor element 101 and the source lead member 102, thereby defining the thickness of the sintered junction layer 104. That is, in the manufacturing process of the semiconductor device 100, by disposing the stopper 106 between the upper surface of the semiconductor element 101 and the source lead member 102, the thickness of the sintered junction layer 104 is prevented from becoming too thin even when the pressure applied to the sintered junction layer 104 is excessive.

[0020] The stopper 106 is preferably made of an insulator such as a heat-resistant resin or ceramic. By making the stopper 106 an insulator, inadvertent electrical conduction in the semiconductor element 101 and the source lead member 102 can be prevented.

[0021] 2 is a cross-sectional view of a circuit body in which the sealing material 110 is removed from the semiconductor device 100 of FIG. 1 according to the first embodiment of the present invention. As shown in FIG. 2, the stopper 106 has a lower end 106a that contacts the upper surface of the semiconductor element 101 and an upper end 106b that contacts the source lead member 102. In this way, the lower end 106a and the upper end 106b of the stopper 106 contact the upper surface of the semiconductor element 101 and the source lead member 102, respectively, thereby ensuring a constant gap between them and defining the thickness of the sintered junction layer 104. That is, the thickness of the sintered junction layer 104 that bonds the upper electrode of the semiconductor element 101 and the source lead member 102 is adjusted according to the length of the stopper 106 in the thickness direction of the semiconductor device 100.

[0022] 3 is a diagram showing an example of the arrangement of the stopper 106 in the source lead member 102. In FIG. 3, three examples of the arrangement of the stopper 106 are shown in layout diagrams (a), (b), and (c). These layout diagrams show the example of the arrangement of the stopper 106 in the structure of the semiconductor device 100 shown in FIG. 1, as a plan view of the source lead member 102, the sintered junction layer 104, and the stopper 106 as viewed from the semiconductor element 101 side.

[0023] In the arrangement example of Fig. 3(a), the stoppers 106 are arranged at the four corners around the sintered junction layer 104 arranged at the center of the source lead member 102. By arranging the stoppers 106 in this manner, even if the range in which the stoppers 106 can be arranged in the source lead member 102 is limited, the stoppers 106 can be freely arranged within that range. Note that, although the arrangement example of Fig. 3(a) shows an example in which the stoppers 106 are arranged at the four corners around the sintered junction layer 104, the stoppers 106 may be arranged at any multiple positions around the sintered junction layer 104.

[0024] In the arrangement example of Fig. 3(b), the stopper 106 is arranged so as to surround the outer periphery of the sintered junction layer 104 arranged at the center of the source lead member 102. By arranging the stopper 106 in this manner, the stopper 106 can be made into an integrated member, so that the time required to install the stopper 106 at a predetermined location in the manufacturing equipment during the manufacturing process can be shortened. Note that, although the arrangement example of Fig. 3(b) shows an example in which the stopper 106 is arranged so as to surround the entire periphery of the sintered junction layer 104, the stopper 106 may be arranged so as to surround only a part of the outer periphery of the sintered junction layer 104.

[0025] In the arrangement example of FIG. 3(c), the stopper 106 is arranged along two opposing short sides of the four sides of a rectangle that forms the periphery of the sintered junction layer 104 arranged at the center of the source lead member 102. By arranging the stopper 106 in this manner, it is possible to achieve both the degree of freedom in the layout of the stopper 106 described in the arrangement example of FIG. 3(a) and the shortening of the installation time in the manufacturing equipment of the stopper 106 described in the arrangement example of FIG. 3(b). In addition, since the shape of the stopper 106 is simplified, it is also possible to reduce the material cost of the stopper 106. Note that, in the arrangement example of FIG. 3(c), an example in which the stopper 106 is arranged along the two short sides of the sintered junction layer 104 is shown, but the stopper 106 may be arranged along any multiple sides of the four sides of a rectangle that forms the periphery of the sintered junction layer 104.

[0026] 3(a), (b), and (c), the stopper 106 is preferably disposed at a position overlapping the sintered junction layer 105 when viewed in the thickness direction of the semiconductor element 101. In this manner, the pressure can be effectively transmitted to the sintering paste 105a forming the sintered junction layer 105 in the additional pressurizing step described below. Therefore, when the sintering paste 105a is thinned in the additional processing step, the thickness can be made uniform with high precision.

[0027] FIG. 4 is a diagram showing an example of a manufacturing process for the semiconductor device 100. As shown in FIG.

[0028] First, as shown in FIG. 4(1), a sintering paste 105a for forming a sintered junction layer 105 is placed on the drain lead member 103.

[0029] 4(2), the semiconductor element 101 is placed on the sintering paste 105a placed on the drain lead member 103. At this time, the semiconductor element 101 is placed such that at least a part of the lower electrode of the upper and lower electrodes of the semiconductor element 101 is in contact with the sintering paste 105a.

[0030] 4(3), the source lead member 102 on which the sintering paste 104a for forming the sintered junction layer 104 is placed is placed above the semiconductor element 101. At this time, the source lead member 102 is placed with the sintering paste 104a facing the upper surface side of the semiconductor element 101.

[0031] Next, as shown in FIG. 4(4), a stopper 106 is placed around the sintering paste 104a on the surface of the source lead member 102 facing the semiconductor element 101.

[0032] 4(3) and (4), the sintering paste 104a may be placed on the source lead member 102 on which the stopper 106 has been formed in advance. In either case, the sintering paste 104a is placed, and a conductor on which the stopper 106 has been formed around the sintering paste 104a is used as the source lead member 102. The sintering paste 104a and the stopper 106 are disposed above the semiconductor element 101 facing the upper surface side of the semiconductor element 101, thereby performing the steps of FIG. 4(3) and (4). Also, the stopper 106 may be disposed on the upper surface of the semiconductor element 101 instead of on the source lead member 102.

[0033] Next, the source lead member 102 arranged above the semiconductor element 101 is lowered, and the sintering paste 104a placed on the source lead member 102 is brought into contact with the upper surface of the semiconductor element 101, as shown in Fig. 4(5). At this time, at least a part of the upper surface electrode formed on the upper surface of the semiconductor element 101 is brought into contact with the sintering paste 104a. As a result, a circuit body is formed in which the source lead member 102, the semiconductor element 101, and the drain lead member 103 overlap each other via the sintering pastes 104a and 105a.

[0034] Next, the circuit body formed as described above is pressurized in a direction in which the source lead member 102 and the drain lead member 103 approach each other. As a result, the sintering pastes 104a and 105a are compressed, and their thickness is gradually reduced while being crushed in the vertical direction to be thinned. At this time, since the sintering paste 104a has a smaller mounting area, it is more likely to be pressed as described above, and is crushed and thinned before the sintering paste 105a. This pressurizing process is continued until the stopper 106 abuts on the upper surface of the semiconductor element 101, as shown in FIG. 4(6), that is, until the thickness of the sintering paste 104a mounted on the source lead member 102 becomes a specified value according to the length of the stopper 106.

[0035] Next, pressure is further applied to the circuit body in which the stopper 106 has come into contact with the upper surface of the semiconductor element 101 by the above-mentioned pressure application process. At this time, the thickness of the sintering paste 104a is restricted by the stopper 106 and does not become any thinner, so the sintering paste 105a is compressed and thinned. This additional pressure application process is continued until the thickness of the sintering paste 105a placed on the drain lead member 103 reaches a specified value, as shown in FIG. 4(7).

[0036] The pressurizing step and the additional pressurizing step described above are preferably performed using a manufacturing facility capable of controlling the pressurizing force and the pressurizing distance. In this case, the manufacturing facility is operated, for example, until the pressurizing force reaches a predetermined value or the thickness of the circuit body after pressurization reaches a predetermined value. As a result, as shown in FIG. 4(7), the stopper 106 abuts on the upper surface of the semiconductor element 101, and the circuit body can be pressed in a direction in which the source lead member 102 and the drain lead member 103 approach each other until the thickness of the sintering paste 105a placed on the drain lead member 103 reaches a specified value.

[0037] Next, the circuit body that has been subjected to the above-mentioned pressurizing step and additional pressurizing step is heated to a predetermined temperature for sintering, thereby sintering the sintering pastes 104a and 105a. As a result, as described in FIG. 1, a sintered junction layer 104 that connects the upper electrode of the semiconductor element 101 to the source lead member 102 and a sintered junction layer 105 that connects the lower electrode of the semiconductor element 101 to the drain lead member 103 are formed. Thereafter, as shown in FIG. 4(8), the circuit body after the sintering step is sealed with a sealing material 110 to form the semiconductor device 100. In this way, the semiconductor device 100 is manufactured.

[0038] FIG. 5 is a diagram showing another example of the manufacturing process of the semiconductor device 100. In FIG.

[0039] In Fig. 5(1) and (2), the same steps as those in Fig. 4(1) and (2), respectively, are carried out.

[0040] 5(3), a sintering paste 104a for forming a sintered junction layer 104 is further placed on the upper surface of the semiconductor element 101 placed on the sintering paste 105a, and a source lead member 102 is placed above the semiconductor element 101 and the sintering paste 104a. At this time, at least a part of the upper surface electrode formed on the upper surface of the semiconductor element 101 is in contact with the sintering paste 104a.

[0041] Next, as shown in FIG. 5(4), a stopper 106 is placed on the surface of the source lead member 102 on the semiconductor element 101 side, at a position outside the sintering paste 104a.

[0042] 5(3) and (4), the source lead member 102 on which the stopper 106 has been formed in advance may be disposed above the semiconductor element 101 and the sintering paste 104a. In either case, the sintering paste 104a is further placed on the upper surface of the semiconductor element 101 disposed on the sintering paste 105a, and a conductor on which the stopper 106 has been formed at a position outside the sintering paste 104a is used as the source lead member 102, and the stopper 106 is disposed above the semiconductor element 101 facing the upper surface side of the semiconductor element 101, thereby performing the steps of FIG. 5(3) and (4). Also, the stopper 106 may be disposed on the upper surface of the semiconductor element 101 instead of the source lead member 102.

[0043] Next, the source lead member 102 arranged above the semiconductor element 101 is lowered, and as shown in Fig. 5(5), the sintering paste 104a placed on the upper surface of the semiconductor element 101 is brought into contact with the source lead member 102. As a result, a circuit body is formed in which the source lead member 102, the semiconductor element 101, and the drain lead member 103 are overlapped with each other via the sintering pastes 104a and 105a.

[0044] 5(6) to 5(8), the same steps as those in Fig. 4(6) to 4(8) are carried out, respectively, to manufacture the semiconductor device 100.

[0045] According to the first embodiment of the present invention described above, the following advantageous effects are achieved.

[0046] (1) A semiconductor device 100 includes a semiconductor element 101 having an upper surface and a lower surface, with an upper surface electrode formed on the upper surface and a lower surface electrode formed on the lower surface, a source lead member 102 which is a conductor electrically connected to the upper surface electrode of the semiconductor element 101, a drain lead member 103 which is a conductor electrically connected to the lower surface electrode of the semiconductor element 101, a sintered junction layer 104 which is made of a conductive sintered body and which joins the upper surface electrode of the semiconductor element 101 to the source lead member 102, a sintered junction layer 105 which is made of a conductive sintered body and which joins the lower surface electrode of the semiconductor element 101 to the drain lead member 103, and a stopper 106 which is disposed between the upper surface of the semiconductor element 101 and the source lead member 102. In this semiconductor device 100, the area of ​​the surface of the sintered junction layer 105 which contacts the lower surface of the semiconductor element 101 is larger than the area of ​​the surface of the sintered junction layer 104 which contacts the upper surface of the semiconductor element 101. Further, the stopper 106 has a lower end 106a that contacts the semiconductor element 101 and an upper end 106b that contacts the source lead member 102. As a result, in the semiconductor device 100 in which sinter layers (sintered bonding layers 104, 105) made of sintered members are formed on both sides of the semiconductor element 101, the thickness of each sinter layer can be precisely defined.

[0047] (2) The semiconductor device 100 is manufactured by the manufacturing method described in the manufacturing steps of Figures 4 and 5. That is, in the manufacturing step of Figure 4, a sintering paste 105a is placed on the drain lead member 103 (Figure 4(1)), and a semiconductor element 101 having an upper surface on which an upper electrode is formed and a lower surface on which a lower electrode is formed is placed on the sintering paste 105a so that at least a part of the lower electrode is in contact with the sintering paste 105a (Figure 4(2)). Then, a source lead member 102 on which a sintering paste 104a is placed and a stopper 106 is formed around the sintering paste 104a is placed above the semiconductor element 101 with the sintering paste 104a and the stopper 106 facing the upper surface side of the semiconductor element 101 (Figures 4(3) and (4)). Thereafter, the sintering paste 104a placed on the source lead member 102 is brought into contact with the upper surface of the semiconductor element 101, thereby forming a circuit body in which the source lead member 102, the semiconductor element 101, and the drain lead member 103 overlap one another via the sintering pastes 104a and 105a (FIG. 4(5)). Then, the stopper 106 comes into contact with the upper surface of the semiconductor element 101, and pressure is applied to the circuit body in a direction in which the source lead member 102 and the drain lead member 103 approach each other until the thickness of the sintering paste 105a placed on the drain lead member 103 reaches a specified value (FIGS. 4(6) and (7)). Furthermore, the sintering pastes 104a and 105a are sintered to form a sintered junction layer 104 that joins the surface electrode of the semiconductor element 101 to the source lead member 102, and a sintered junction layer 105 that joins the bottom electrode of the semiconductor element 101 to the drain lead member 103, and the circuit body after this sintering process is sealed (FIG. 4(8)). In this manner, the thicknesses of the sintered junction layers 104 and 105 can be precisely defined, and the semiconductor device 100 having the structure shown in FIG. 1 can be manufactured.

[0048] (3) In the manufacturing process of FIG. 5, sintering paste 105a is placed on drain lead member 103 (FIG. 5(1)), and semiconductor element 101 having an upper surface on which an upper electrode is formed and a lower surface on which a lower electrode is formed is placed on this sintering paste 105a so that at least a part of the lower electrode is in contact with sintering paste 105a (FIG. 5(2)). Then, sintering paste 104a is further placed on the upper surface of semiconductor element 101 placed on sintering paste 105a (FIG. 5(3)), and source lead member 102 having stopper 106 formed at a position outside sintering paste 104a is placed above semiconductor element 101 with stopper 106 facing the upper surface side of semiconductor element 101 (FIG. 5(4)). Thereafter, the sintering paste 104a placed on the upper surface of the semiconductor element 101 is brought into contact with the source lead member 102, forming a circuit body in which the source lead member 102, the semiconductor element 101, and the drain lead member 103 overlap one another via the sintering pastes 104a and 105a (FIG. 5(5)). Then, the stopper 106 comes into contact with the upper surface of the semiconductor element 101, and pressure is applied to the circuit body in a direction in which the source lead member 102 and the drain lead member 103 approach each other until the thickness of the sintering paste 105a placed on the drain lead member 103 reaches a specified value (FIGS. 5(6), (7)). Furthermore, the sintering pastes 104a and 105a are sintered to form a sintered junction layer 104 that joins the surface electrode of the semiconductor element 101 to the source lead member 102, and a sintered junction layer 105 that joins the lower electrode of the semiconductor element 101 to the drain lead member 103, and the circuit body after this sintering process is sealed (FIG. 5(8)). In this manner, the thicknesses of the sintered junction layers 104 and 105 can be precisely defined in the same manner as in the manufacturing process of FIG. 4, and the semiconductor device 100 having the structure shown in FIG. 1 can be manufactured.

[0049] Second Embodiment Next, a second embodiment of the present invention will be described.

[0050] Fig. 6 is a diagram showing the configuration of a semiconductor device according to a second embodiment of the present invention. Like Fig. 2 in the first embodiment, Fig. 6 shows a cross-sectional view of a circuit body in which the sealing material 110 (Fig. 1) has been removed from the semiconductor device of this embodiment. That is, the semiconductor device of this embodiment has a structure in which the circuit body shown in Fig. 6 is sealed with sealing material 110. The semiconductor device of this embodiment will be described below using the circuit body in Fig. 6.

[0051] The semiconductor device of this embodiment is different from the semiconductor device 100 of FIG. 1 described in the first embodiment in that it further includes a stopper 107. This stopper 107 is disposed between the source lead member 102 and the drain lead member 103. When the sintering paste is compressed to form the sintering junction layers 104 and 105 as described in the first embodiment, the stopper 107 plays a role of ensuring a certain distance between the source lead member 102 and the drain lead member 103 and defining the thickness of the sintering junction layer 105. That is, in the manufacturing process of FIG. 4 and FIG. 5 described in the first embodiment, when forming a circuit body (see FIG. 4(5) and FIG. 5(5)) in which the source lead member 102, the semiconductor element 101, and the drain lead member 103 overlap each other via the sintering pastes 104a and 105a, the stopper 107 is disposed between the source lead member 102 and the drain lead member 103. Then, in the subsequent additional pressurizing step (see FIG. 4(7) and FIG. 5(7)), the circuit body is pressed until the stoppers 107 come into contact with the source lead member 102 and the drain lead member 103, respectively, thereby setting the thickness of the sintering paste 105a placed on the drain lead member 103 to a specified value. This prevents the thickness of the sinter junction layer 105 from becoming too thin.

[0052] Like the stopper 106, the stopper 107 is preferably made of an insulator such as a heat-resistant resin or ceramic. By making the stopper 107 an insulator, inadvertent electrical conduction through the source lead member 102 and the drain lead member 103 can be prevented.

[0053] According to the second embodiment of the present invention described above, the semiconductor device further includes the stopper 107 disposed between the source lead member 102 and the drain lead member 103. This makes it possible to more accurately define the thickness of the sintered junction layer 105.

[0054] The present invention is not limited to the above-described embodiment, and other embodiments that are conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention as long as they do not impair the characteristics of the present invention. In addition, the above-described embodiment may be combined with a number of modified examples. [Explanation of symbols]

[0055] 100: semiconductor device, 101: semiconductor element, 102: source lead member, 103: drain lead member, 104, 105: sintered junction layers, 104a, 104b: sintering paste, 106, 107: stopper, 110: sealing material

Claims

1. a semiconductor element having an upper surface and a lower surface, an upper surface electrode formed on the upper surface, and a lower surface electrode formed on the lower surface; a first conductor electrically connected to the upper electrode; a second conductor electrically connected to the lower electrode; a first sintered bonding layer made of a conductive sintered body and bonding the upper electrode and the first conductor; a second sintered bonding layer made of a conductive sintered body and bonding the lower electrode and the second conductor; a stopper disposed between the upper surface and the first conductor; an area of ​​a surface of the second sintered bonding layer in contact with the lower surface is larger than an area of ​​a surface of the first sintered bonding layer in contact with the upper surface; the stopper has a lower end that contacts the semiconductor element and an upper end that contacts the first conductor. Semiconductor device.

2. 2. The semiconductor device according to claim 1, The stopper is formed of an insulator. Semiconductor device.

3. 2. The semiconductor device according to claim 1, a second stopper disposed between the first conductor and the second conductor; Semiconductor device.

4. 2. The semiconductor device according to claim 1, the stopper is disposed at a position overlapping the second sintered junction layer when viewed in a thickness direction of the semiconductor element; Semiconductor device.

5. 2. The semiconductor device according to claim 1, The stoppers are disposed at a plurality of positions around the first sintered junction layer. Semiconductor device.

6. 2. The semiconductor device according to claim 1, The stopper is disposed so as to surround the outer periphery of the first sintered bonding layer. Semiconductor device.

7. 2. The semiconductor device according to claim 1, The stoppers are disposed along a plurality of sides among four sides of a rectangle that forms an outer periphery of the first sintered junction layer. Semiconductor device.

8. A sintering paste is placed on the second conductor; a semiconductor element having an upper surface on which an upper electrode is formed and a lower surface on which a lower electrode is formed is disposed on the sintering paste placed on the second conductor such that at least a portion of the lower electrode is in contact with the sintering paste; a first conductor on which the sintering paste is placed and on which a stopper is formed around the sintering paste is disposed above the semiconductor element with the sintering paste and the stopper facing the upper surface side; By bringing the sintering paste placed on the first conductor into contact with the upper surface, a circuit body is formed in which the first conductor, the semiconductor element, and the second conductor are overlapped with each other via the sintering paste; The circuit body is pressed in a direction in which the first conductor and the second conductor approach each other until the stopper comes into contact with the upper surface and the thickness of the sintering paste placed on the second conductor reaches a specified value; A sintering process is performed to sinter the sintering paste to form a first sintered bonding layer that bonds the upper electrode and the first conductor, and a second sintered bonding layer that bonds the lower electrode and the second conductor; The circuit body is sealed after the sintering process. A method for manufacturing a semiconductor device.

9. A sintering paste is placed on the second conductor; a semiconductor element having an upper surface on which an upper electrode is formed and a lower surface on which a lower electrode is formed is disposed on the sintering paste placed on the second conductor such that at least a portion of the lower electrode is in contact with the sintering paste; The sintering paste is further placed on the upper surface of the semiconductor element disposed on the sintering paste; a first conductor having a stopper formed at a position outside the sintering paste placed on the upper surface is placed above the semiconductor element with the stopper facing the upper surface; by bringing the sintering paste placed on the upper surface into contact with the first conductor, a circuit body is formed in which the first conductor, the semiconductor element, and the second conductor are overlapped with each other via the sintering paste; The circuit body is pressed in a direction in which the first conductor and the second conductor approach each other until the stopper comes into contact with the upper surface and the thickness of the sintering paste placed on the second conductor reaches a specified value; A sintering process is performed to sinter the sintering paste to form a first sintered bonding layer that bonds the upper electrode and the first conductor, and a second sintered bonding layer that bonds the lower electrode and the second conductor; The circuit body is sealed after the sintering process. A method for manufacturing a semiconductor device.

10. 10. The method for manufacturing a semiconductor device according to claim 8, further comprising the steps of: When forming the circuit body, a second stopper is disposed between the first conductor and the second conductor; by applying pressure to the circuit body until the second stopper abuts against the first conductor and the second conductor, respectively, the thickness of the sintering paste placed on the second conductor is set to the specified value. A method for manufacturing a semiconductor device.

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