Semiconductor device and manufacturing method thereof

Abstract

To provide a semiconductor device capable of improving quality and a method for manufacturing the same.SOLUTION: A semiconductor device includes: a lead frame 2 having a plurality of die bonding units 3 each being electrically independent; a power semiconductor element 4 provided on each of the die bonding units 3; a wire 7 electrically connecting the power semiconductor element 4 and the lead frame 2; epoxy resin 12 provided at least at part of the lead frame 2; and sealing resin 8 for covering at least each of the die bonding units 3, the power semiconductor element 4, the wire 7, and the epoxy resin 12.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor device and a method for manufacturing the same. [Background technology]

[0002] A conventional semiconductor device includes a lead frame having a shape disclosed in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-63688 Summary of the Invention [Problem to be solved by the invention]

[0004] Before transfer molding, i.e., before covering a portion of the lead frame with insulating sealing resin, the semiconductor device has exposed components such as the lead frame and metal wires. Therefore, conventional semiconductor devices have problems such as lead frame deformation, metal wire deformation, or breakage of metal wire bonds due to vibration during handling in the manufacturing process. Such deformation or breakage can cause short circuits between different electrodes, posing a challenge to the quality assurance of the semiconductor device.

[0005] Furthermore, the molding resin typically used in transfer molding is an opaque black resin primarily composed of epoxy, designed to provide heat resistance and reduce internal stress. This makes it difficult to check for deformation or fracture after transfer molding, and requires a significant amount of time for screening out defective or deteriorated products.

[0006] As described above, there is still room for improvement in the quality of conventional semiconductor devices.

[0007] The present disclosure has been made to solve such problems, and has an object to provide a semiconductor device and a manufacturing method thereof that enable improvement in quality. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, a semiconductor device according to the present disclosure includes a lead frame having a plurality of die pad portions each electrically independent from the other, a semiconductor element provided on each die pad portion, wires electrically connecting the semiconductor element and the lead frame, an epoxy-based resin provided on at least a part of the lead frame, and a sealing resin covering at least each die pad portion, the semiconductor element, the wires, and the epoxy-based resin, wherein the epoxy-based resin is provided on at least one of the top surface and the side surface of the end of each of the opposing sides of adjacent die pad portions. A sealing resin is interposed between the epoxy resins provided on the adjacent die pad portions. are. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to improve the quality of semiconductor devices. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing an example of the appearance of a semiconductor device according to a first embodiment. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] 1A to 1C are diagrams illustrating an example of a manufacturing process of the semiconductor device according to the first embodiment. [Figure 4] FIG. 3 is a diagram for explaining a step of applying an epoxy liquid resin according to the first embodiment. [Figure 5] 1A to 1C are diagrams illustrating an example of a manufacturing process of the semiconductor device according to the first embodiment. [Figure 6] 1A to 1C are diagrams illustrating an example of a manufacturing process of the semiconductor device according to the first embodiment. [Figure 7] 1A to 1C are diagrams illustrating an example of a manufacturing process of the semiconductor device according to the first embodiment. [Figure 8]1 is a cross-sectional view showing an example of the configuration of a molding device according to a first embodiment. [Figure 9] 1 is a top view showing an example of the configuration of a molding apparatus according to a first embodiment. [Figure 10] 1 is a cross-sectional view showing an example of the configuration of a molding apparatus according to a first embodiment. [Figure 11] 1 is a top view showing an example of the configuration of a molding apparatus according to a first embodiment. [Figure 12] FIG. 10 is a diagram showing an example of the configuration of a semiconductor device according to a second embodiment. [Figure 13] FIG. 10 is a diagram showing an example of the configuration of a semiconductor device according to a third embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing an example of the configuration of a semiconductor device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] <First Embodiment> <Configuration> Fig. 1 is a schematic diagram showing an example of the appearance of a semiconductor device 1 according to embodiment 1. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1.

[0012] 2, the semiconductor device 1 includes a lead frame 2, a die pad portion 3, a power semiconductor element 4, an IC chip 5, a bonding material 6, metal wires 7, a mold resin 8 (sealing resin), an insulating layer 9, a heat dissipation layer 10, and an epoxy-based liquid resin 12 (epoxy-based resin). Note that the epoxy-based liquid resin 12 is not shown in FIG.

[0013] The lead frame 2 has a plurality of die pad portions 3, for example, as shown in FIG. 3. Each die pad portion 3 is electrically independent. A power semiconductor element 4 is provided on each die pad portion 3 via a bonding material 6. In the example of FIG. 2, two power semiconductor elements 4 are provided on one die pad portion 3. The power semiconductor elements 4 are, for example, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) or IGBTs (Insulated Gate Bipolar Transistors).

[0014] The power semiconductor element 4 is electrically connected to other power semiconductor elements 4 provided on the same die pad portion 3 by metal wires 7, and is also electrically connected to the lead frame 2 protruding to the outside from one side of the molded resin 8 by metal wires 7.

[0015] An IC chip 5 is provided on the lead frame 2, which protrudes to the outside from the other surface of the molded resin 8, via a bonding material 6. Here, the other surface of the molded resin 8 refers to the surface opposite to the one surface of the molded resin 8. The IC chip 5 is electrically connected to the other power semiconductor element 4 by a metal wire 7.

[0016] An insulating layer 9 is provided on the rear surface of the die pad portion 3. On the rear surface of the insulating layer 9, a heat dissipation layer 10 is provided.

[0017] The mold resin 8 is provided so as to cover (seal) a part of the lead frame 2, the die pad portion 3, the power semiconductor element 4, the IC chip 5, the metal wires 7, the insulating layer 9, and a part of the heat dissipation layer 10. The heat dissipation layer 10 is exposed from a part of the back surface of the mold resin 8. The mold resin 8 has insulating properties.

[0018] <Manufacturing method> 3 to 7 are diagrams showing an example of a manufacturing process for the semiconductor device 1. Note that the insulating layer 9 and the heat dissipation layer 10 are omitted from the drawings in FIGS.

[0019] First, as shown in FIG. 3, a power semiconductor element 4 is provided on a die pad portion 3, and an IC chip 5 is provided on a lead frame 2.

[0020] Next, as shown in FIGS. 4 and 5, an epoxy liquid resin 12 is applied to the upper end surface of the lead frame 2 including the die pad portion 3. Specifically, the epoxy liquid resin 12 is applied to the upper end surfaces of the lead frame 2 and the die pad portion 3 shown in FIG. 5 using a syringe 11 shown in FIG. 4. The epoxy liquid resin 12 hardens after application to form an insulating layer. The linear expansion coefficient of the epoxy liquid resin 12 is set to 15 to 18 [×10] taking into account the linear expansion coefficient of the mold resin 8. -6 / °C], but is not limited to this. The epoxy liquid resin 12 used is one that is hardenable at room temperature or at constant temperature.

[0021] Syringe 11 is provided in an epoxy liquid resin application device (not shown). The epoxy liquid resin application device can move syringe 11 in any of the X, Y, and Z directions to apply epoxy liquid resin 12 at any location. Note that the driving method of syringe 11 and the discharging method of epoxy liquid resin 12 are not particularly limited.

[0022] Next, as shown in Figure 6, two power semiconductor elements 4 provided on the same die pad portion 3 are connected by metal wires 7, the power semiconductor elements 4 and the lead frame 2 are connected by metal wires 7, and the power semiconductor elements 4 and the IC chip 5 are connected by metal wires 7.

[0023] Next, as shown in FIG. 7, a molding resin 8 is provided so as to cover a part of the lead frame 2, the die pad portion 3, the power semiconductor element 4, the IC chip 5, the metal wires 7, and the epoxy liquid resin 12.

[0024] Transfer molding using molding resin 8 is performed using, for example, a molding device shown in Figures 8 to 11. The molding device includes an upper mold 13, a lower mold 14, a plunger 15, a cavity 16, and a gate 17. Cavity 16 has a shape corresponding to the outer shape of semiconductor device 1.

[0025] As shown in Figures 8 and 9, the pot (the space surrounded by the lower mold 14 and plunger 15) is filled with molding resin 8. The lead frame 2 in the state shown in Figure 6 is placed in the cavity 16. Note that the lead frame 2 is not shown in Figures 8 to 11. As shown in Figures 10 and 11, the molding resin 8 is melted by the heat of the upper mold 13 and the lower mold 14, and is injected into the cavity 16 through the gate 17 as the plunger 15 rises. This results in the semiconductor device after molding shown in Figure 7. Thereafter, the semiconductor device is cut out from the lead frame 2, and the portions of the lead frame 2 corresponding to the terminals are bent, and the semiconductor device 1 shown in Figure 1 is obtained.

[0026] <Effects> Conventionally, in the process from wiring the metal wires to transfer molding, there has been a problem in that the lead frame or the metal wires may be deformed during handling, causing short circuits between different electrodes.

[0027] On the other hand, in the first embodiment, the epoxy liquid resin 12 is applied to the upper surfaces of the ends of the lead frame 2 and the die pad portion 3, so that it is possible to ensure an insulating distance between different electrodes (between adjacent lead frames 2, between adjacent die pad portions 3, and between adjacent lead frames 2 and die pad portions 3). This makes it possible to improve the quality of the semiconductor device 1.

[0028] Although the above describes the case where the epoxy liquid resin 12 is applied to the upper surfaces of the ends of the lead frame 2 and the die pad portion 3, the same effect can be obtained even if the epoxy liquid resin 12 is applied to the side surfaces of the lead frame 2 and the die pad portion 3. Note that the epoxy liquid resin 12 may be applied to at least one of the upper surfaces and side surfaces of the ends of the lead frame 2 and the die pad portion 3.

[0029] <Embodiment 2> <Configuration and manufacturing method> 12 is a cross-sectional view showing an example of the configuration of a semiconductor device according to the second embodiment. The semiconductor device according to the second embodiment is characterized by including metal wires 20 having an epoxy liquid resin (epoxy resin) on the surface thereof. Other configurations are the same as those of the semiconductor device 1 according to the first embodiment, and therefore detailed description thereof will be omitted here. Note that the mold resin 8, insulating layer 9, and heat dissipation layer 10 are not shown in FIG. 12.

[0030] The epoxy liquid resin application device moves a syringe 11 in any of the X, Y, and Z directions to apply epoxy liquid resin to the surface of the metal wire 7 shown in Fig. 6, for example. The epoxy liquid resin applied to the surface of the metal wire 7 is cured to obtain the metal wire 20.

[0031] <Effects> Applying an epoxy liquid resin to the metal wire makes it possible to reinforce the metal wire against deformation. In a semiconductor device including the metal wire 20, it is possible to prevent breakage of the metal wire bond due to vibration, which is a problem for metal wires with a wire diameter of 100 μm or less. As a result, the semiconductor device according to the second embodiment can have higher quality than the semiconductor device according to the first embodiment.

[0032] <Third Embodiment> <Configuration and manufacturing method> FIG. 13 is a cross-sectional view showing an example of the configuration of a semiconductor device according to the third embodiment. The semiconductor device according to the third embodiment is characterized in that an epoxy-based liquid resin 30 is provided at the joint between the metal wire 7 and the lead frame 2, the joint between the metal wire 7 and the power semiconductor element 4, and the joint between the metal wire 7 and the IC chip 5. The joints are also called stitches. The other configurations are the same as those of the semiconductor device 1 according to the first embodiment, so a detailed description will be omitted here. Note that the mold resin 8, insulating layer 9, and heat dissipation layer 10 are not shown in FIG. 13.

[0033] The epoxy liquid resin application device moves syringe 11 in any of the X, Y, and Z directions to apply epoxy liquid resin to each joint shown in Fig. 13. The epoxy liquid resin applied to each joint hardens to obtain epoxy liquid resin 30.

[0034] <Effects> Metal wire deformation develops from the bonded portion of the metal wire. As shown in FIG. 13, by providing the bonded portion with epoxy liquid resin 30 to reinforce it, it is possible to prevent the metal wire from being deformed and to prevent the metal wire bonded portion from being broken due to vibration. Furthermore, since it is only necessary to apply the epoxy liquid resin to the bonded portion, it is possible to apply the epoxy liquid resin without being affected by variations in the wiring shape of the metal wire. As a result, the semiconductor device according to the third embodiment can have improved quality compared to the semiconductor device according to the first embodiment.

[0035] Although the configuration in which the semiconductor device 1 according to the first embodiment is provided with the epoxy liquid resin 30 has been described above, the semiconductor device according to the second embodiment may also be provided with the epoxy liquid resin 30. In this configuration, the effects of the second embodiment can be obtained in addition to the effects of the third embodiment described above.

[0036] <Fourth Embodiment> <Configuration and manufacturing method> 14 is a cross-sectional view showing an example of the configuration of a semiconductor device according to embodiment 4. The semiconductor device according to embodiment 4 is characterized in that it has an epoxy-based liquid resin 40 on the underside of the die pad portion 3, and a part of the epoxy-based liquid resin 40 is exposed from the mold resin 8. That is, the semiconductor device according to embodiment 4 has the epoxy-based liquid resin 40 instead of the insulating layer 9 and the heat dissipation layer 10 in the semiconductor device 1 according to embodiment 1. Since the other configurations are the same as those of the semiconductor device 1 according to embodiment 1, detailed description thereof will be omitted here.

[0037] The epoxy liquid resin 40 has improved thermal conductivity by applying a surface treatment to the filler, which is one of the ingredients. The thermal conductivity of the epoxy liquid resin 40 is 7 W / m K or higher.

[0038] <Effects> In the semiconductor device 1 having the insulating layer 9 and heat dissipation layer 10 described in the first embodiment, a problem has been encountered in achieving the characteristics thereof, namely, a decrease in adhesion at the interface between the die pad portion 3 of the lead frame 2 and the insulating layer 9. In contrast, the semiconductor device according to the fourth embodiment uses a highly thermally conductive epoxy-based liquid resin 40, and the liquid epoxy-based liquid resin 40 improves the adhesion between the die pad portion 3 and the epoxy-based liquid resin 40. This makes it possible to improve the quality of the semiconductor device.

[0039] Furthermore, the materials constituting insulating layer 9 and heat dissipation layer 10 are expensive materials for semiconductor devices because of the high manufacturing costs and difficulty involved due to the required properties. By using epoxy-based liquid resin 40 instead of insulating layer 9 and heat dissipation layer 10 as in the semiconductor device according to the fourth embodiment, the number of materials can be reduced, thereby enabling a reduction in the manufacturing cost of the semiconductor device.

[0040] Although the above description has been made of a configuration in which the insulating layer 9 and the heat dissipation layer 10 in the semiconductor device 1 according to the first embodiment are replaced with the epoxy-based liquid resin 40, the present invention is not limited to this. For example, the semiconductor device according to the second or third embodiment may be configured to include the epoxy-based liquid resin 40 instead of the insulating layer 9 and the heat dissipation layer 10. In this configuration, the effects of the second or third embodiment can be obtained in addition to the effects of the fourth embodiment. Furthermore, instead of providing the epoxy-based liquid resin 12 on the surfaces of the lead frame 2 and the die pad portion 3 as in the first to third embodiments, the epoxy-based liquid resin 40 may be provided only on the underside of the die pad portion 3.

[0041] Within the scope of the present disclosure, the embodiments can be freely combined, modified, or omitted as appropriate. [Explanation of symbols]

[0042] 1 semiconductor device, 2 lead frame, 3 die pad portion, 4 power semiconductor element, 5 IC chip, 6 bonding material, 7 metal wire, 8 molding resin, 9 insulating layer, 10 heat dissipation layer, 11 syringe, 12 epoxy-based liquid resin, 13 upper mold, 14 lower mold, 15 plunger, 16 cavity, 17 gate, 20 metal wire, 30 epoxy-based liquid resin, 40 epoxy-based liquid resin.

Claims

1. a lead frame having a plurality of die pad portions each electrically independent from the others; a semiconductor element provided on each of the die pad portions; a wire electrically connecting the semiconductor element and the lead frame; an epoxy resin provided on at least a portion of the lead frame; a sealing resin that covers at least the die pad portions, the semiconductor element, the wires, and the epoxy resin; Equipped with the epoxy resin is provided on at least one of the top surface and the side surface of each of the opposing ends of the adjacent die pad portions, The semiconductor device, wherein the sealing resin is interposed between the epoxy resins provided on the adjacent die pad portions.

2. 2. The semiconductor device according to claim 1, wherein said epoxy resin is provided on at least one of an upper surface and a side surface of an end portion of said lead frame.

3. 3. The semiconductor device according to claim 1, wherein the epoxy resin is provided on the lower surface of the die pad portion, and at least a part of the epoxy resin is exposed from the sealing resin.

4. 4. The semiconductor device according to claim 3, wherein the thermal conductivity of said epoxy resin is 7 W / m·K or more.

5. The semiconductor device according to claim 1 , wherein the epoxy resin is provided on the surface of the wire.

6. 6. The semiconductor device according to claim 1, wherein the epoxy resin is provided at a joint between the wire and the lead frame and at a joint between the wire and the semiconductor element.

7. a first step of preparing a lead frame having a plurality of die pad portions each electrically independent from the others; a second step of providing a semiconductor element on each of the die pad portions; a third step of applying an epoxy resin to at least a portion of the lead frame; a fourth step of electrically connecting the semiconductor element and the lead frame with wires; a fifth step of covering at least the die pad portion, the semiconductor element, the wires, and the epoxy resin with a sealing resin; Equipped with In the third step, the epoxy resin is applied to at least one of the top surface and the side surface of each of the opposing sides of the adjacent die pad portions.

8. 8. The method for manufacturing a semiconductor device according to claim 7, wherein in said third step, said epoxy resin is applied to at least one of an upper surface and a side surface of an end portion of said lead frame.

9. In the third step, the epoxy resin is also applied to the lower surface of the die pad portion, 9. The method for manufacturing a semiconductor device according to claim 7, wherein in the fifth step, the sealing resin is provided so that a part of the epoxy resin provided on the lower surface of the die pad portion is exposed.

10. 10. The method for manufacturing a semiconductor device according to claim 9, wherein the thermal conductivity of the epoxy resin is 7 W / m·K or more.

11. 11. The method for manufacturing a semiconductor device according to claim 7, further comprising a sixth step between the fourth step and the fifth step of providing the epoxy resin on the surface of the wire.

12. 12. The method for manufacturing a semiconductor device according to claim 7, wherein in the third step, the epoxy resin is applied to the lead frame by an epoxy liquid resin application device.

13. The method for manufacturing a semiconductor device according to claim 7 , wherein the epoxy resin is a liquid epoxy resin.

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