Semiconductor devices

Abstract

The semiconductor device of the embodiment of the present invention has a semiconductor chip, a molded resin having a rectangular parallelepiped shape and a concave portion at the end of the bottom surface, and a first terminal provided on a first upper surface of the concave portion and electrically connected to the semiconductor chip.

Description

[0001] Related Applications

[0002] This application claims priority based on Japanese Patent Application No. 2021-46291 (filing date: March 19, 2021). This application incorporates all the contents of the basic application by reference. Technical Field

[0003] Embodiments of the present invention relate to a semiconductor device. Background Art

[0004] Power semiconductor chips designed for power control such as MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) and IGBT (Insulated Gate Bipolar Transistor) are being developed for a wide range of fields such as power generation and transmission, rotating machines such as pumps and blowers, power supply devices such as communication systems and factories, railways using AC motors, electric vehicles, and household electrical products.

[0005] In addition, semiconductor devices are being developed as power supply components using the power semiconductor chips, which require high current density, low loss, high heat dissipation and other technical conditions. Summary of the invention

[0006] Embodiments provide a semiconductor device having improved supply capability.

[0007] The semiconductor device of the embodiment includes a semiconductor chip; a molded resin having a rectangular parallelepiped shape and a recessed portion at an end of a bottom surface provided around the semiconductor chip; and a first terminal provided on a first upper surface of the recessed portion and electrically connected to the semiconductor chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 (a) to (c) are schematic diagrams of semiconductor devices according to embodiments.

[0009] Figure 2 is a schematic cross-sectional view of a semiconductor device according to an embodiment.

[0010] Figure 3 (a) and (b) are schematic bottom views of the semiconductor device according to the embodiment.

[0011] Figure 4 This is a flow chart of a process for manufacturing a semiconductor device according to an embodiment.

[0012] Figure 5(a) and (b) are schematic perspective views of a semiconductor device of a comparative embodiment. DETAILED DESCRIPTION

[0013] Below, while referring to the attached Figure 1 In the following description, the same components and the like are denoted by the same reference numerals, and the description of components and the like that have been described previously will be appropriately omitted.

[0014] In this specification, in order to indicate the positional relationship of components, the upper direction of the drawings is expressed as "up" and the lower direction of the drawings is expressed as "down". In this specification, the concepts of "up" and "down" are not necessarily terms indicating the relationship with the direction of gravity.

[0015] (Implementation Method)

[0016] The semiconductor device of the embodiment includes: a semiconductor chip; a molded resin disposed around the semiconductor chip and having a rectangular parallelepiped shape and a recessed portion at an end of a bottom surface; and a first terminal disposed on a first upper surface of the recessed portion and electrically connected to the semiconductor chip.

[0017] Figure 1 Schematic diagram of a semiconductor device 100 according to an embodiment. Figure 1 (a) is a schematic perspective view of a semiconductor device 100 according to an embodiment. Figure 1 (b) is a schematic bottom view of the semiconductor device 100 according to the embodiment. Figure 1 (c) is a schematic cross-sectional view of a main part of the semiconductor device 100 according to the embodiment in a plane parallel to the XZ plane. Figure 2 Schematic cross-sectional view of the semiconductor device 100 according to the embodiment in a plane parallel to the XZ plane.

[0018] use Figure 1 and Figure 2 , a semiconductor device 100 according to an embodiment is described.

[0019] Lead frame 2( Figure 2 ) is a plate-shaped member on which the semiconductor chip 4 is configured and which includes a conductive material such as copper (Cu).

[0020] The semiconductor chip 4 ( Figure 2) is, for example, arranged on the lead frame 2. The semiconductor chip 4 is, for example, a vertical MOSFET or IGBT (Insulated Gate Bipolar Transistor), but is not limited thereto. For example, when the semiconductor chip 4 is a MOSFET, the drain electrode 5 arranged on the bottom surface of the semiconductor chip 4 is electrically connected to the lead frame 2 through a bonding material (not shown) arranged between the semiconductor chip 4 and the lead frame 2. Here, solder or a conductive resin containing silver particles is used as the bonding material. For example, a source electrode 6 and a gate electrode 7 are arranged on the top of the semiconductor chip 4.

[0021] The injection resin 10 is disposed around the semiconductor chip 4. The injection resin 10 is a resin for sealing the semiconductor chip 4. The injection resin 10 is, for example, a resin such as epoxy resin. In addition, the injection resin 10 may further contain a filler such as silicon oxide. The injection resin 10 has a rectangular parallelepiped shape. A recess 12 is provided at an end 11a of the bottom surface 11 of the injection resin 10.

[0022] Here, an X direction, a Y direction perpendicular to the X direction, and a Z direction perpendicular to the X direction and the Y direction are defined. A bottom surface 11 of the molded resin 10 is parallel to the XY plane.

[0023] For example, Figure 1 (a) and Figure 1 As shown in (b), on the bottom surface 11 of the injection resin 10, recessed portions 12a and 12b are provided at the end portions 11a and 11b facing each other.

[0024] The first upper surface 14a is provided on the recessed portion 12a. The first terminals 20a, 20b, 20c, and 20d are provided on the first upper surface 14a.

[0025] The first upper surface 14b is provided on the recessed portion 12b. The first terminal 20e, the first terminal 20f, the first terminal 20g, and the first terminal 20h are provided on the first upper surface 14b.

[0026] like Figure 2 As shown, the first terminal 20a is connected to the lead frame 2. Here, as described above, the lead frame 2 is connected to the drain electrode 5 of the semiconductor chip 4. Therefore, the first terminal 20a is electrically connected to the drain electrode 5 of the semiconductor chip 4. In addition, although not shown in the figure, the first terminal 20b, the first terminal 20c, and the first terminal 20d are also electrically connected to the drain electrode 5 of the semiconductor chip 4.

[0027] like Figure 2As shown, the first terminal 20e is connected to the gate electrode 7 of the semiconductor chip 4 via, for example, a bonding wire 8. In addition, the first terminal 20e may be connected to the gate electrode 7 via a tape, a clamp, or a connector. In addition, although not shown in the figure, the first terminal 20f, the first terminal 20g, and the first terminal 20h are also electrically connected to the source electrode 6 of the semiconductor chip 4 via, for example, a bonding wire, a tape, a clamp, or a connector. In addition, the bonding wire 8, the tape, the clamp, or the connector includes Cu (copper), Al (aluminum), Au (gold), or Ag (silver).

[0028] The second terminal 30 is a plate-shaped member. The second terminal 30 has a second upper surface 32. The thickness of the second terminal 30 is, for example, about 100 μm. For example, the sum t3 (the thickness of the first terminal 20 in the Z direction and the thickness of the second terminal 30 in the Z direction) Figure 2 (as shown in the figure) is preferably 0.23 mm to 0.33 mm based on JEDEC MP240.

[0029] The first terminal 20 and the second terminal 30 include metal materials such as Au (gold), Ag (silver), Cu (copper), and Ni (nickel).

[0030] The sintered material 40 ( Figure 1 (c)) is disposed on the second upper surface 32. The first portion 42 of the sintered material 40 is connected to the first terminal 20. The second portion 44 and the portion of the second terminal 30 where the second portion 44 is disposed are disposed so as to protrude from the mold resin 10 and the recess 12.

[0031] The sintered material 40 has conductivity. Here, as the sintered material 40, for example, a sintered material 40 using particles of Ag (silver), Cu (copper) or Ni (nickel) is preferably used. Before sintering, for example, a protective film is provided on the surface of fine particles (nanoparticles or microparticles) such as Ag or Cu, and the material is dispersed in an organic solvent. Then, by sintering, the protective film and the organic solvent evaporate, and the sintered material 40 is formed.

[0032] In addition, the sintering material 40 may further contain a resin. This is because the heat resistance can be further ensured by containing a resin. Here, the resin is not particularly limited, and for example, epoxy resin is preferably used.

[0033] For example, when the sintered material 40 does not contain resin, it can be sintered while applying pressure to the portion joined, for example, using a crimping machine. When the sintered material 40 contains resin, it can also be sintered without applying the above pressure. In addition, the sintering process is not limited to the above description.

[0034] For example, a depletion portion 46 is provided in the first portion 42 and the second portion 44 of the sintered material 40. The depletion portion 46 is formed, for example, by evaporation of a protective film, an organic solvent, or a resin during the sintering. The proportion of the depletion portion 46 in the sintered material 40 is preferably 20% or less of the sintered material. Furthermore, the proportion of the metal in the sintered material 40 is preferably 80% or more of the sintered material 40. In addition, the number or shape of the depletion portion 46 is not limited to Figure 1 (c) as shown.

[0035] The film thickness of the sintered material 40 is preferably 5 μm to 200 μm.

[0036] The film thickness t2 of the second portion 44 is preferably thicker than the film thickness t1 of the first portion 42 .

[0037] The film thickness of the first portion 42 is, for example, approximately 20 μm. The film thickness of the second portion 44 is, for example, approximately 40 μm.

[0038] The length of the protruding portion of the second terminal 30 from the molded resin 10 is preferably as short as possible in order to improve conductivity, and is preferably 100 μm or less, for example.

[0039] The second terminal 30 preferably includes a base material portion 34 including Cu (copper), and a film 50 provided on the bottom surface 36 (an example of the surface) of the base material portion 34 or the side surface 38 (an example of the surface) of the base material portion 34. Here, as an example of the first film, the film 50 preferably includes a metal that can be soldered, such as Sn (tin), Au (gold), Cu (copper), or Ag (silver). In addition, as an example of the second film, a film containing N (nitrogen) such as BTA (benzotriazole) is preferred.

[0040] The materials used in the semiconductor device 100, the dimensions of the components of the semiconductor device 100, the proportion of the depletion portion 46, etc. can be measured by SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), Auger electron spectroscopy, XPS (X-ray Photoelectron spectroscopy), and EDX (Energy Dispersive X-ray spectroscopy).

[0041] Figure 3 FIG. 2 is a schematic bottom view of a semiconductor device according to an embodiment of the present invention. Figure 3As shown in (a), in the bottom surface 11, the second terminals 30a, 30b, 30c and 30d electrically connected to the drain electrode 5 of the semiconductor chip 4 are preferably arranged opposite to the second terminals 30f, 30g and 30h electrically connected to the source electrode 6 of the semiconductor chip 4. Figure 3 As shown in (b), the second terminal 30a, the second terminal 30b, the second terminal 30c electrically connected to the drain electrode 5 of the semiconductor chip 4 and the second terminal 30f, the second terminal 30g and the second terminal 30h electrically connected to the source electrode 6 of the semiconductor chip 4 can also be respectively arranged on adjacent edges in the bottom surface 11.

[0042] Figure 4 This is a flow chart of a process for manufacturing a semiconductor device according to an embodiment.

[0043] First, as a "lead frame" step, the lead frame 2 is prepared (S2).

[0044] Next, as a “semiconductor chip fixing” step and a “first terminal fixing” step, the semiconductor chip 4 is fixed to the lead frame 2 using a bonding material such as solder.

[0045] Next, as “flux cleaning”, when the bonding material used for fixing the semiconductor chip 4 contains flux, the flux is cleaned ( S6 ).

[0046] Next, as a "wire bonding" step, source electrode 6 and gate electrode 7 of semiconductor chip 4 are connected to first terminal 20 using bonding wire 8 (S8). Alternatively, bonding wire 8 may be replaced with a tape, a jig, or a connector for connection.

[0047] Next, as an “injection molding” step, the lead frame 2 , the semiconductor chip 4 , and the first terminal 20 are sealed using the injection resin 10 ( S10 ).

[0048] Next, as "blade cutting", in order to form the recessed portion 12, the bottom surface 11 of the injection resin 10 is cut in two stages using a blade. First, the bottom surface 11 of the injection resin 10 is cut in the Z direction using a first blade. Here, when the first blade is used, the injection resin 10 is not completely cut in the Z direction. Next, a second blade thinner than the first blade is used to cut the portion of the bottom surface 11 of the injection resin 10 cut by the first blade in the Z direction. Then, singulation is performed with the injection molding shape (S12). In this way, the recessed portion 12 can be formed.

[0049] Next, as a “second terminal fixing” step, the second terminal 30 having the sintered material 40 before sintering provided on the second upper surface 32 is fixed to the recessed portion ( S14 ).

[0050] Next, as a “pressing and pressing” step, the sintered material 40 is formed on the second upper surface 32 by heating and pressing, and the second terminal 30 and the first terminal 20 are bonded together ( S16 ).

[0051] Next, as a "plating" step, a film 50 is formed on the bottom surface 36 and the side surface 38 of the second terminal 30 by, for example, plating. In this way, the semiconductor device 100 of the embodiment is obtained.

[0052] In addition, the method for manufacturing the semiconductor device 100 according to the embodiment is not limited to the above-mentioned method.

[0053] Next, the effects of the semiconductor device according to the embodiment will be described.

[0054] Figure 5 It is a schematic perspective view of a semiconductor device 800 of a comparative embodiment.

[0055] In the semiconductor device in which the semiconductor chip 4 is sealed with the molding resin 10, there is Figure 5 (a) shows a semiconductor device 800a in which the first terminal 20 does not protrude from the molded resin 10; Figure 5 (b) A device in which the first terminal 20 protrudes from the injection resin 10, such as the semiconductor device 800b. Since the first terminal 20 of the semiconductor device 800a does not protrude from the injection resin 10, it can be mounted on a substrate such as a printed circuit board (not shown) at a high density. On the other hand, since the first terminal 20 of the semiconductor device 800b protrudes from the injection resin 10, it can be bonded to a substrate such as a printed circuit board (not shown) with a larger actual mounting area (bonding area) than the semiconductor device 800a. Therefore, since the actual mounting area is increased, higher reliability can be obtained.

[0056] Thus, even if the semiconductor device uses the same semiconductor chip 4, there are cases where semiconductor device 800a is required and cases where semiconductor device 800b is required, depending on the purpose. However, since the manufacturing processes of semiconductor device 800a and semiconductor device 800b are different, it is sometimes difficult to provide the required device according to the purpose of use or customer requirements.

[0057] Therefore, the semiconductor device of the embodiment includes: a semiconductor chip 4; a molded resin 10 arranged around the semiconductor chip 4 and having a rectangular parallelepiped shape and a recessed portion at the end of the bottom surface; and a first terminal 20 provided on the first upper surface 14 of the recessed portion and electrically connected to the semiconductor chip 4.

[0058] According to this semiconductor device, by using the semiconductor device without the second terminal 30 or the semiconductor device with the second terminal 30 separately, it is also possible to provide Figure 5Therefore, a semiconductor device having improved supply capability can be provided.

[0059] By further comprising: a second terminal 30 having a second upper surface 32; and a sintered material 40 provided on the second upper surface 32 and having a first portion 42 connected to the first terminal 20 and a second portion 44 protruding from the recess, a semiconductor device can be provided in which a terminal protrudes from the injection resin 10. In addition, by providing the second portion 44, heat dissipation from the semiconductor chip 4 via the first terminal 20 and the second terminal 30 is improved.

[0060] The sintered material 40 containing Ag (silver), Cu (copper) or Ni (nickel) shows good conductivity. In addition, when the semiconductor device 100 is actually mounted on a substrate such as a printed circuit board using solder or the like, the sintered material 40 does not melt at a temperature of about 260° C. Therefore, the semiconductor device 100 can be actually mounted on a substrate such as a printed circuit board well.

[0061] When the second terminal 30 is joined to the first terminal 20 by pressurization, the first portion 42 is crushed by the pressurization because it is connected to the first terminal 20. Therefore, the film thickness t2 of the second portion 44 not connected to the first terminal 20 is thicker than the film thickness t1 of the first portion 42.

[0062] During sintering, a depletion portion 46 is formed in the sintered material 40. When the proportion of the depletion portion 46 is 20% or less of the sintered material 40, good conductivity can be obtained due to the increase in metal.

[0063] When the second terminal 30 includes the base material portion 34 containing Cu (copper) and the film 50 containing a solder-bondable metal provided on the surface of the base material portion 34 , actual mounting on a substrate such as a printed circuit board can be easily performed.

[0064] When the second terminal 30 includes the base material portion 34 containing Cu (copper) and the film 50 containing N (nitrogen) provided on the surface of the base material portion 34 , the second terminal 30 having high oxidation resistance can be obtained.

[0065] The film thickness of the sintered material 40 is preferably 5 μm to 200 μm. This is because if the film thickness is less than 5 μm, the bonding between the first terminal 20 and the second terminal 30 is reduced. If the film thickness is greater than 200 μm, the volume of the depletion portion 46 increases and the strength tends to decrease.

[0066] According to the semiconductor device of the embodiment, it is possible to provide a semiconductor device having improved supply capability.

[0067] Several embodiments of the present invention are described, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or their variations are included in the scope or spirit of the invention, and are also included in the invention described in the claims and their equivalents.

Claims

1. A semiconductor device comprising: Semiconductor chips; A molded resin provided around the semiconductor chip and having a rectangular parallelepiped shape and having a recessed portion at an end of a bottom surface; and a first terminal disposed on a first upper surface of the recess and electrically connected to the semiconductor chip; The semiconductor device further comprises a second terminal having a second upper surface; and a sintered material provided on the second upper surface and having a first portion connected to the first terminal and a second portion protruding from the recessed portion, The sintered material has a depleted portion, The sintered material is formed by sintering, and the depletion portion is formed by evaporation of a protective film, an organic solvent, or a resin during the sintering.

2. The semiconductor device according to claim 1, wherein The film thickness of the second portion is thicker than the film thickness of the first portion.

3. The semiconductor device according to claim 2, wherein: The sintering material includes Ag (silver), Cu (copper) or Ni (nickel).

4. The semiconductor device according to claim 1 or 2, wherein: The ratio of the depleted portion of the sintered material is 20% or less of the sintered material.

5. The semiconductor device according to claim 1 or 2, wherein: The second terminal includes a base material portion containing Cu (copper) and a first film provided on a surface of the base material portion and containing a solder-bondable metal.

6. The semiconductor device according to claim 1 or 2, wherein: The second terminal includes a base material portion containing Cu (copper) and a second film provided on a surface of the base material portion and containing N (nitrogen).

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