Semiconductor device and method of manufacturing the same

Abstract

Embodiments provide a semiconductor device with high reliability and a manufacturing method thereof. The semiconductor device of the embodiments includes a die pad, a bonding member provided on the die pad and having conductivity, a semiconductor chip provided on the bonding member, and a sealing member provided on the bonding member and the semiconductor chip. The bonding member has a central portion in contact with the semiconductor chip and a peripheral portion around the central portion, and an upper surface of the peripheral portion has unevenness.

Description

[0001] Reference to relevant applications

[0002] This application enjoys priority based on Japanese Patent Application No. 2025-042803 (filed on March 17, 2025). By referring to that basic application, this application incorporates the entire contents of the basic application. Technical Field

[0003] Embodiments of the present invention relate to semiconductor devices and methods for manufacturing the same. Background Technology

[0004] Semiconductor components such as MOSFETs are commercialized as semiconductor packages. Power devices using silicon carbide (SiC) substrates can achieve high voltage withstand and low on-resistance, thus enabling the flow of large drain current.

[0005] For example, a drain electrode is disposed on the bottom surface of a semiconductor device, and a source electrode and a gate electrode are disposed on its top surface. The semiconductor device is bonded to a die pad using solder or the like, and then sealed with molding resin.

[0006] In semiconductor devices containing such semiconductor packages, the solder-resin adhesion is poor, and therefore, the resin sometimes peels off from the solder. In this case, the reliability of the semiconductor device decreases. Additionally, cracks sometimes form around the solder. In particular, when thermal cycling tests are performed on the semiconductor device, cracks forming around the solder accelerate solder embrittlement. Consequently, the resistance between the drain and source increases. Summary of the Invention

[0007] The problem to be solved by the present invention is to provide a semiconductor device with high reliability.

[0008] The semiconductor device of the embodiment includes: a die pad; a bonding member disposed on the die pad and having conductivity; a semiconductor chip disposed on the bonding member; and a sealing member disposed on the bonding member and the semiconductor chip. The bonding member has a central portion in contact with the semiconductor chip and a peripheral portion surrounding the central portion, the upper surface of the peripheral portion having irregularities. Attached Figure Description

[0009] Figure 1 This is a top view of the semiconductor device according to the first embodiment.

[0010] Figure 2 It is along Figure 1 A cross-sectional view of the semiconductor device shown by the AA′ line.

[0011] Figure 3 It is a cross-sectional view of a portion of a magnified semiconductor device.

[0012] Figure 4 This is a top view illustrating one step in the manufacturing process of a semiconductor device.

[0013] Figure 5 This is a cross-sectional view illustrating one step in the manufacturing process of a semiconductor device.

[0014] Figure 6 This is a top view illustrating one step in the manufacturing process of a semiconductor device.

[0015] Figure 7 This is a cross-sectional view illustrating one step in the manufacturing process of a semiconductor device.

[0016] Figure 8 This is a cross-sectional view illustrating one step in the manufacturing process of a semiconductor device.

[0017] Figure 9 This is a top view illustrating one step in the manufacturing process of a semiconductor device.

[0018] Figure 10 This is a cross-sectional view illustrating one step in the manufacturing process of a semiconductor device.

[0019] Figure 11 This is a top view illustrating one step in the manufacturing process of a semiconductor device.

[0020] Figure 12 This is a cross-sectional view illustrating one step in the manufacturing process of a semiconductor device.

[0021] Figure 13 This is a top view of the die in the modified example.

[0022] Figure 14 It is along Figure 13 A cross-sectional view of the die with the CC′ line.

[0023] Figure 15 This is a cross-sectional view illustrating one step of the manufacturing method of a modified semiconductor device.

[0024] Figure 16 This is a top view of the mold according to the second embodiment.

[0025] Figure 17 It is along Figure 16 A cross-sectional view of the die with the CC′ line.

[0026] (Explanation of reference numerals in the attached diagram)

[0027] 1: Semiconductor device; 10: Die pad; 11: Bonding component; 12: Semiconductor chip; 13: Terminal; 14: Sealing component; 15: Molding die. Detailed Implementation

[0028] Hereinafter, embodiments will be described with reference to the accompanying drawings. Some embodiments shown below illustrate apparatus and methods for embodying the technical concept of the present invention, which is not limited by the shape, structure, or arrangement of components. In the following description, elements having the same function and structure are labeled with the same reference numerals, and repeated descriptions are omitted.

[0029] [1] First Embodiment

[0030] [1-1] Structure of semiconductor device 1

[0031] Figure 1 This is a top view of the semiconductor device 1 according to the first embodiment. Figure 2 It is along Figure 1 A cross-sectional view of semiconductor device 1 with AA′ line shown. Figure 1 In this diagram, the X direction is the direction along one side of the semiconductor device 1, and the Y direction is the direction orthogonal to the X direction. The semiconductor device 1 includes a semiconductor chip and a semiconductor package that seals the semiconductor chip. In this embodiment, a QFN (Quad Flat Non-leaded package) will be used as an example of a type of semiconductor package.

[0032] The semiconductor device 1 includes a die pad 10, a conductive bonding component 11, a semiconductor chip 12, multiple terminals 13, and a sealing component 14.

[0033] The die pad 10 functions to support and fix the semiconductor chip 12. The die pad 10 is, for example, rectangular. The die pad 10 is made of a metal such as copper (Cu).

[0034] A bonding member 11 is provided on the die pad 10. The bonding member 11 is conductive. The bonding member 11 functions to bond the die pad 10 and the semiconductor chip 12. The bonding member 11 is constructed using solder (including molten solder and solder paste) or silver (Ag) paste. In this embodiment, solder 11 will be used as an example of the bonding member 11.

[0035] A semiconductor chip 12 is disposed on solder 11. The semiconductor chip 12 includes semiconductor elements. The semiconductor chip 12 may include elements primarily composed of silicon (Si) or primarily composed of silicon carbide (SiC). The semiconductor chip 12 may be, for example, a MOS field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT). In this embodiment, the case where the semiconductor chip 12 is a MOSFET will be described as an example. The semiconductor chip 12 may be rectangular, for example.

[0036] For example, a drain electrode is disposed on the bottom surface of the semiconductor chip 12, and a source electrode and a gate electrode are disposed on its top surface. The drain electrode of the semiconductor chip 12 is electrically connected to the die pad 10 via solder 11. The semiconductor chip 12 is also referred to as a die.

[0037] A plurality of terminals 13 are arranged around the die pad 10. The plurality of terminals 13 are respectively disposed on the four sides of the semiconductor device 1. The plurality of terminals 13 are made of a metal such as copper (Cu). The plurality of terminals 13 are electrically connected to the semiconductor chip 12 using a plurality of bonding wires (not shown).

[0038] The sealing component 14 seals the semiconductor chip 12. The sealing component 14 is, for example, rectangular. The sealing component 14 is made of resin.

[0039] Next, the specific structure of solder 11 will be explained. Figure 3 It is a part of the amplifying semiconductor device 1. Figure 2 A cross-sectional view of region AR1. Figure 3 The shape of solder 11 is shown schematically. The actual shape of solder 11 is sometimes rounded.

[0040] The area of ​​solder 11 is set to be larger than the area of ​​semiconductor chip 12. That is, when viewed from above, solder 11 is formed in a manner that extends out of semiconductor chip 12. Solder 11 has a central portion 11A and a peripheral portion 11B surrounding the central portion 11A. The central portion 11A is the portion that is in contact with semiconductor chip 12. The peripheral portion 11B is the portion that extends out of semiconductor chip 12.

[0041] The upper surface of the peripheral portion 11B has irregularities. The irregularities on the upper surface of the peripheral portion 11B are formed all around the periphery of the peripheral portion 11B. The multiple grooves forming the irregularities of the solder 11 have a rectangular frame shape when viewed from above.

[0042] A sealing member 14 is provided on the peripheral portion 11B of the solder 11. The sealing member 14 is also formed in the groove of the peripheral portion 11B of the solder 11. The unevenness of the peripheral portion 11B provides an anchoring effect to the sealing member 14. That is, the bonding force between the peripheral portion 11B of the solder 11 and the sealing member 14 is increased. As a result, it is possible to prevent the solder 11 from peeling off from the sealing member 14.

[0043] [1-2] Manufacturing method

[0044] Next, the manufacturing method of semiconductor device 1 will be described using the accompanying drawings. In this embodiment, the area of ​​the die pad 10 will be extracted for description, and the illustration of the plurality of terminals 13 is omitted. The plurality of terminals 13 are formed together with the die pad 10 into a lead frame, and are formed in the same manufacturing process as the die pad 10.

[0045] Figures 4 to 12 These are diagrams illustrating one step of the manufacturing method of semiconductor device 1. Figure 4 , Figure 6 , Figure 9 , Figure 11 This is a top view illustrating one step in the manufacturing method of semiconductor device 1. Figure 5 , Figure 7 , Figure 8 , Figure 10 , Figure 12 This is a cross-sectional view illustrating one step of the manufacturing method of semiconductor device 1 along line BB′ in the top view.

[0046] like Figure 4 and Figure 5 As shown, prepare die pad 10. Then, use a solder supply device (not shown) to melt the solder and apply solder 11 to the die pad.

[0047] Then, as Figure 6 and Figure 7 As shown, prepare the spanker 15. In Figure 7 The image also shows an enlarged view of a portion of the die 15 (the portion surrounded by a dashed circle). A die is a device used in the die bonding process to shape solder supplied by a solder supply device into a uniform thickness that matches the dimensions of the mounted die. In this embodiment, the die refers to a component that directly contacts the solder and shapes it.

[0048] The mold 15 is made of an insulating material, such as hard rubber. The mold 15 has a rectangular planar shape. The area of ​​the mold 15 is set according to the area of ​​the semiconductor chip 12, and has an area slightly larger than the semiconductor chip 12. The mold 15 has a rectangular flat portion 15A and a protrusion 15B protruding downwards from the outer periphery of the flat portion 15A. The bottom surface of the flat portion 15A is flat. The planar shape of the protrusion 15B is a rectangular frame shape. The protrusion 15B has a plurality of grooves 15C on its bottom surface. The plurality of grooves 15C are formed parallel to each side of the outer periphery of the mold 15. Each of the plurality of grooves 15C has a rectangular frame shape in planar shape. Figure 7 As an example, the protrusion 15B is shown to have a structure with three slots 15C. The number and width of the slots 15C can be arbitrarily set.

[0049] Then, as Figure 8 As shown, the solder 11 is shaped by pressing the die 15 from above. The solder 11 is shaped with its upper surface flat. In addition, the peripheral portion of the solder 11 is shaped to enter the groove 15C of the die 15.

[0050] Figure 9 and Figure 10 This diagram illustrates the manufacturing process after solder 11 is formed. Figure 10 The diagram also shows an enlarged view of a portion of the solder 11 (the area enclosed by a dashed circle). The solder 11 is configured to have a planarized central portion 11A and a peripheral portion 11B surrounding the central portion 11A. The central portion 11A is rectangular. The peripheral portion 11B has a rectangular frame shape. The upper surface of the peripheral portion 11B has irregularities. A plurality of grooves forming the irregularities of the solder 11 each have a rectangular frame shape. The irregularities formed on the upper surface of the peripheral portion 11B have, for example, shapes that substantially correspond to the shapes of the grooves 15C of the die 15. The irregularities formed on the upper surface of the peripheral portion 11B may not perfectly correspond to the shapes of the grooves 15C. In this case, for example, the number of grooves 15C of the die 15 is the same as the number of protrusions formed on the upper surface of the irregularities of the peripheral portion 11B.

[0051] Then, as Figure 11 and Figure 12 As shown, a semiconductor chip 12 is placed on solder 11. Then, although not shown in the figure, multiple bonding wires are used to electrically connect the semiconductor chip 12 to multiple terminals 13.

[0052] Then, as Figure 1 and Figure 2 As shown, the semiconductor chip 12 is sealed with resin to form a sealing component 14.

[0053] [1-3] Variations

[0054] Next, variations of the manufacturing method will be explained.

[0055] Figure 13 This is a top view of the modified die 15. Figure 14 It is along Figure 13 A cross-sectional view of the die 15 with the CC′ line. Figure 14 The image also shows an enlarged view of a portion of the mold 15 (the part surrounded by a dashed circle).

[0056] The mold 15 is made of an insulating material, such as hard rubber. The mold 15 has a rectangular flat portion 15A and a protrusion 15B that protrudes downward from the outer periphery of the flat portion 15A. The bottom surface of the protrusion 15B is flat.

[0057] A plurality of protrusions 15D are provided on the bottom surface of protrusion 15B. The plurality of protrusions 15D are made of an insulating material, such as hard rubber. The plurality of protrusions 15D are formed parallel to each side of the outer periphery of the mold 15. Each of the plurality of protrusions 15D has a rectangular frame shape. Figure 14 As an example, the mold 15 is shown to have a structure with three protrusions 15D. The number and width of the protrusions 15D can be set arbitrarily.

[0058] Figure 15 This is a cross-sectional view illustrating one step of the manufacturing method of the modified semiconductor device 1. For example... Figure 15 As shown, solder 11 is shaped by pressing it from above using a die 15. The peripheral portion of the solder 11 is shaped such that it enters the gaps of a plurality of protrusions 15D in the die 15. Thus, in a modified example, it is also possible to form irregularities on the peripheral portion of the solder 11. The irregularities formed on the upper surface of the peripheral portion 11B have, for example, shapes corresponding to the shapes of the grooves 15C in the die 15. The irregularities formed on the upper surface of the peripheral portion 11B may not perfectly match the shapes of the grooves 15C. In this case, for example, the number of grooves 15C in the die 15 is the same as the number of protrusions formed on the upper surface of the peripheral portion 11B.

[0059] According to the first embodiment, an uneven surface is formed around the periphery of the solder 11, and a sealing member 14 is formed by resin entering into this uneven surface. Therefore, through the anchoring effect of the solder 11, the adhesion between the solder 11 and the sealing member 14 can be improved, thus preventing the sealing member 14 from peeling off from the solder 11. Furthermore, the adhesion between the solder 11 and the sealing member 14 can be improved. Therefore, a highly reliable semiconductor device 1 can be realized.

[0060] Furthermore, the improved adhesion between the solder 11 and the sealing component 14 helps to suppress cracking within the solder 11. This enables the realization of a highly reliable semiconductor device 1. Additionally, it helps to suppress the increase in resistance along the current path through the solder 11. For example, it helps to suppress the increase in resistance (on-resistance) between the drain and source of a MOSFET.

[0061] [2] Second Embodiment

[0062] The second embodiment is another structural example of the mold 15, wherein the mold 15 is configured to include a material with high thermal conductivity.

[0063] Figure 16 This is a top view of the mold 15 in the second embodiment. Figure 17 It is along Figure 16 A cross-sectional view of the die 15 with the CC′ line. Figure 17 The image also shows an enlarged view of a portion of the mold 15 (the part surrounded by a dashed circle).

[0064] The mold 15 has a rectangular flat portion 15A and a protrusion 15B that protrudes downward from the outer periphery of the flat portion 15A. The bottom surface of the flat portion 15A is flat. The flat portion 15A is made of an insulating material, such as hard rubber.

[0065] The protrusion 15B is made of a material with high thermal conductivity. For example, it may be made of metals such as copper (Cu) or tungsten (W). The protrusion 15B has multiple grooves 15C on its bottom surface. These grooves 15C are formed parallel to the outer periphery of the mold 15. Each groove 15C has a rectangular frame shape in planar shape. The number and width of the grooves 15C can be arbitrarily set.

[0066] The manufacturing method of semiconductor device 1 is the same as in the first embodiment. Solder 11 is formed using the mold 15 of the second embodiment. In this case, the solder 11 solidifies at different times in the portion contacting the flat portion 15A and the portion contacting the protrusion 15B. That is, the solder portion contacting the protrusion 15B solidifies faster than the solder portion contacting the flat portion 15A. As a result, the unevenness of the peripheral portion 11B of the solder 11 is easily maintained. Then, a sealing member 14 is formed in a manner that penetrates the unevenness of the solder 11.

[0067] According to the second embodiment, it is possible to easily form irregularities on the solder 11. As a result, the adhesion between the solder 11 and the sealing member 14 can be improved.

[0068] Furthermore, while QFN was used as an example of a semiconductor package in the above embodiments, it is not a limitation thereof. This embodiment can be applied to various semiconductor packages with die pads.

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

Claims

1. A semiconductor device comprising: die pads; The bonding component, disposed on the die pad, is conductive; A semiconductor chip is disposed on the bonding member; and A sealing component is disposed on the bonding component and the semiconductor chip. The bonding member has a central portion that contacts the semiconductor chip and a peripheral portion surrounding the central portion. The upper surface of the peripheral portion has irregularities.

2. The semiconductor device according to claim 1, wherein, The sealing component is configured to engage with the concave and convex portions of the peripheral portion.

3. The semiconductor device according to claim 1, wherein, The plurality of grooves forming the joint component each have a rectangular frame shape.

4. The semiconductor device according to claim 1, wherein, The joining components include solder.

5. The semiconductor device according to claim 1, wherein, The sealing component is made of resin.

6. The semiconductor device according to claim 1, wherein, It also features multiple terminals arranged around the die pads. The sealing component is configured to seal the die pads and the plurality of terminals integrally.

7. A method for manufacturing a semiconductor device, Apply conductive bonding components to the die pads. The joining component is formed using a die, the die having a flat portion, a protrusion projecting downward from the outer periphery of the flat portion, and a plurality of grooves provided in the protrusion. The semiconductor chip is placed on the bonding component. The semiconductor chip is sealed with resin, and a sealing component is formed on the semiconductor chip and the bonding component.

8. The method for manufacturing a semiconductor device according to claim 7, wherein, The protrusion has a rectangular frame shape. The plurality of slots each have a rectangular frame shape.

9. The method for manufacturing a semiconductor device according to claim 7, wherein, The flat portion and the protruding portion are made of insulating material.

10. The method of manufacturing a semiconductor device according to claim 7, wherein, The flat portion is made of insulating material. The protrusion is made of metal.

11. The method of manufacturing a semiconductor device according to claim 7, wherein, The joining components include solder.

12. The method of manufacturing a semiconductor device according to claim 7, wherein, The sealing component is made of resin.

13. The method of manufacturing a semiconductor device according to claim 7, wherein, The bonding member has a central portion that contacts the semiconductor chip and a peripheral portion surrounding the central portion. The upper surface of the peripheral portion has irregularities formed by the plurality of grooves of the mold.

14. The method of manufacturing a semiconductor device according to claim 13, wherein, The sealing component is configured to engage with the concave and convex portions of the peripheral portion.

15. The method of manufacturing a semiconductor device according to claim 13, wherein, The plurality of grooves forming the joint component each have a rectangular frame shape.

16. The method of manufacturing a semiconductor device according to claim 13, wherein, The number of protrusions in the engagement component is the same as the number of grooves in the mold.

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