Semiconductor device and method of manufacturing semiconductor device

Abstract

A semiconductor device and a method for manufacturing the semiconductor device are provided. In a semiconductor device sealed with a sealing material, deformation of the wires connecting the semiconductor elements is suppressed while maintaining the insulating distance between the semiconductor elements. The semiconductor device of the present invention includes a first semiconductor element (4), a second semiconductor element (5), a wire (6b) connecting the first semiconductor element (4) and the second semiconductor element (5), a first frame portion (9) provided with the first semiconductor element (4), a second frame portion (10) provided with the second semiconductor element (5) disposed above the first frame portion (9) and disposed away from it in the left-right direction, and a sealing member (2). A recess (14) is provided on the upper surface (10a) of the second frame portion (10) and is recessed downward. The recess is located above the first frame portion (9), and the second semiconductor element (5) is fixed in the recess (14).

Description

Technical Field

[0001] This disclosure relates to a semiconductor device and a method for manufacturing a semiconductor device. Background Technology

[0002] Patent Document 1 discloses an example of a resin-sealed power semiconductor device. In this semiconductor device, a power semiconductor element is disposed on the upper surface of a chip pad, and a thick-film substrate is bonded to multiple support internal leads located above the chip pad via a bonding layer. On the upper surface of the thick-film substrate, the control circuit pattern for the power semiconductor element is entirely formed as a thick-film pattern, and the semiconductor element for the control circuit is mounted on the thick-film pattern via solder. The electrodes of the power semiconductor element are electrically connected to the thick-film pattern via wires. Furthermore, by positioning the support internal leads above the chip pad, an insulating distance is maintained between the power semiconductor element disposed on the chip pad and the semiconductor element on the support internal leads. Therefore, the wires have the length required to maintain the insulating distance.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-250911 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The resin-sealed power semiconductor device of Patent Document 1 is manufactured, for example, by transfer molding. During this molding process, a sealing material such as resin is injected between two semiconductor elements. On the other hand, a long, thin wire of the required length to maintain an insulating distance is provided between the two semiconductor elements. Therefore, because the sealing material injected between the two semiconductor elements during molding causes stress to act on the wire, the wire may deform.

[0008] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a semiconductor device and a method for manufacturing a semiconductor device that can suppress deformation of the wires connecting the semiconductor elements to each other while maintaining the insulation distance between semiconductor elements in a semiconductor device sealed by a sealing material.

[0009] Technical means for solving technical problems

[0010] The semiconductor device disclosed herein includes: a first semiconductor element; a second semiconductor element connected to the first semiconductor element; a wire connecting the first semiconductor element and the second semiconductor element; a first frame portion on which the first semiconductor element is disposed; a second frame portion disposed above the first frame portion and spaced apart in a left-right direction, and on which the second semiconductor element is disposed; and a sealing member sealing the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and the wire, wherein a downwardly recessed recess is provided on the upper surface of the second frame portion, the recess being located above the first frame portion, and the second semiconductor element is fixed in the recess.

[0011] The method for manufacturing a semiconductor device disclosed herein includes: a preparation step of preparing a first frame portion and a second frame portion disposed at a position above and far away in the left-right direction relative to the first frame portion; a mounting step of mounting a first semiconductor element on the first frame portion and mounting a second semiconductor element on the second frame portion; a connection step of connecting the first semiconductor element and the second semiconductor element via wires; and a sealing step of sealing the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and the wires with a sealing material. In this process, a first mold having a forming recess, a second mold having a forming protrusion corresponding to the forming recess and configured opposite to the forming recess and movable relative to the first mold, and a base plate for the second frame portion are prepared. The base plate is placed in the region of the first mold containing the forming recess. The base plate is advanced towards the first mold by the second mold and stamped, thereby forming the second frame portion. A recess that is recessed downward and located on the upper side of the first frame portion is formed on the formed second frame portion. In the mounting process, the second semiconductor element is fixed in the recess.

[0012] Invention Effects

[0013] According to the semiconductor device and the method for manufacturing the semiconductor device disclosed herein, it is possible to suppress the deformation of wires while maintaining the insulating distance between semiconductor elements in a semiconductor device sealed by a sealing material. Attached Figure Description

[0014] Figure 1 This is a perspective view of the semiconductor device involved in Embodiment 1.

[0015] Figure 2 This is a cross-sectional view of the semiconductor device according to Embodiment 1.

[0016] Figure 3 This is a perspective view showing the main parts within the semiconductor device according to Embodiment 1.

[0017] Figure 4 This is a flowchart illustrating a method for manufacturing a semiconductor device according to Embodiment 1.

[0018] Figure 5 This is a perspective view showing the process of manufacturing the lead frame of the semiconductor device according to Embodiment 1.

[0019] Figure 6 This is a perspective view showing the process of manufacturing the lead frame of the semiconductor device according to Embodiment 1.

[0020] Figure 7 This is a perspective view showing the main parts within the semiconductor device according to Embodiment 2.

[0021] Figure 8 This is a front view of the recess of the second frame portion of the semiconductor device according to Embodiment 2.

[0022] Figure 9 This is a top view of the recess of the second frame portion of the semiconductor device according to Embodiment 2.

[0023] Figure 10 This is a perspective view showing the process of manufacturing the lead frame of the semiconductor device according to Embodiment 2.

[0024] Figure 11 This is a perspective view showing the main parts within the semiconductor device according to Embodiment 3.

[0025] Figure 12 This is a front view of the recess of the second frame portion of the semiconductor device according to Embodiment 3.

[0026] Figure 13 This is a top view of the recess of the second frame portion of the semiconductor device according to Embodiment 3.

[0027] Figure 14 This is a perspective view showing the process of manufacturing the lead frame of the semiconductor device according to Embodiment 3.

[0028] Figure 15 This is a perspective view showing the main parts within the semiconductor device according to Embodiment 4.

[0029] Figure 16 This is a cross-sectional view of the semiconductor device according to Embodiment 4.

[0030] Figure 17This is a front view of the recess of the second frame portion of the semiconductor device according to Embodiment 4.

[0031] Figure 18 This is a perspective view showing the process of manufacturing the lead frame of the semiconductor device according to Embodiment 4.

[0032] Figure 19 This is a cross-sectional view showing the process of manufacturing the lead frame of the semiconductor device according to Embodiment 4.

[0033] Figure 20 This is a cross-sectional view showing a modified example of the semiconductor device according to Embodiment 1. Detailed Implementation

[0034] In the following description, terms such as "up" and "down" are used to indicate direction. However, "up" and "down" only indicate the relative direction in the semiconductor device and do not limit the direction of the semiconductor device during manufacturing or use.

[0035] Implementation method 1.

[0036] The following description uses the accompanying drawings to illustrate Embodiment 1 of this disclosure. Figure 1 This is a perspective view showing the semiconductor device 1 according to Embodiment 1. Figure 2 This shows a cross-section of semiconductor device 1. Figure 1 A sectional view along line AA.

[0037] like Figure 1 As shown, the semiconductor device 1 includes a sealing member 2 and a plurality of external terminals 3 exposed from the sealing member 2. The sealing member 2 is a rectangular plate made of resin. The external terminals 3 are arranged and configured along the front-to-back direction on the left side 2a and right side 2b of the sealing member 2. Each external terminal 3 extends outward in the left-to-right direction from the sides 2a and 2b of the sealing member 2, and bends at approximately a right angle and extends upward. The external terminals 3 are mounted on a control board having control circuitry (not shown) and are electrically connected to the outside of the semiconductor device 1. Figure 2 As shown, a first semiconductor element 4, a second semiconductor element 5, a wire 6, a lead frame 7, and an insulating sheet 8 are disposed inside the sealing member 2. Additionally, Figure 2 The portion of the external terminal 3 that bends upwards is not shown in the diagram.

[0038] Figure 3 This is a perspective view showing the main parts within the semiconductor device 1, including the first semiconductor element 4, the second semiconductor element 5, the wire 6, and the lead frame 7.

[0039] The first semiconductor element 4 is made of silicon (Si) and is a so-called power semiconductor element for controlling electrical power. Examples of the first semiconductor element 4 include IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and FWDs (Freewheeling Diodes). One side of the first semiconductor element 4 is, for example, about 3mm to 13mm in diameter. The first semiconductor element 4 is not limited to Si and can also be a wide-bandgap semiconductor element such as SiC or GaN. The first semiconductor element 4 is mounted on the first frame portion 9 of the lead frame 7.

[0040] The second semiconductor element 5 is an IC (integrated circuit) that controls the first semiconductor element 4, such as an HVIC (high-side gate driver) or LVIC (low-side gate driver). The second semiconductor element 5 is mounted on the second frame portion 10 of the lead frame 7 and is electrically connected to the first semiconductor element 4 via wires 6. The size of the second semiconductor element 5 is smaller than, for example, that of an IGBT or MOSFET. Since the current value used for control is small, the wiring connection is made by ball bonding using wires 6.

[0041] The wire 6 can be made of any metal, such as pure Al or a conductive metal with Al as its main component. The wire 6 includes a wire 6a connecting the first semiconductor element 4 and the lead frame 7, and a wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5. When the first semiconductor element 4 is an IGBT, wire 6a connects the collector electrode on the upper surface of the IGBT to the lead frame 7. When the first semiconductor element 4 is an IGBT, wire 6b connects the gate electrode of the IGBT to the second semiconductor element 5. Wire 6b is thinner than wire 6a; the diameter of wire 6a is, for example, 200 μm to 400 μm, and the diameter of wire 6b is, for example, 30 μm to 60 μm.

[0042] A first semiconductor element 4 and a second semiconductor element 5 connected to the first semiconductor element 4 are mounted on the lead frame 7 and connected by wiring wires 6b to form a circuit within the semiconductor device 1. The thickness of the lead frame 7 is, for example, about 0.3 to 1.0 mm. The lead frame 7 and the external terminal 3 are formed from a single plate-shaped metal. The lead frame 7 and the external terminal 3 are obtained by cutting and shaping the single plate-shaped metal using a mold, thereby obtaining the lead frame 7 and the external terminal 3 with a stepped structure. The material of the lead frame 7 and the external terminal 3 is a conductive metal material with Cu as the main component, or an alloy such as Cu-Mo, which is better in addition to conductivity, can also be used.

[0043] The lead frame 7 has a first frame portion 9 on which a first semiconductor element 4 is disposed; and a second frame portion 10 disposed on the upper side relative to the first frame portion 9 and in the left-right direction (right side in this embodiment).

[0044] A plurality of first frame portions 9 are disposed within the sealing member 2, and these first frame portions 9 are arranged along the front-back direction from the center of the left-right direction within the sealing member 2. The first frame portions 9 are the chip pad portions of the lead frame 7. An insulating sheet 8 for electrical insulation is provided on the lower surface of the first frame portions 9. The insulating sheet 8 may also be sandwiched between the upper first frame portions 9 and the lower heat sink 11. In this case, a portion of the heat sink 11 is exposed from the sealing member 2. Alternatively, an insulating substrate may be used for the first frame portions 9. In that case, the second frame portion 10 may also be a metal terminal replacing the lead frame 7, and the second semiconductor element 5 may also be mounted on this metal terminal.

[0045] The first frame portion 9 is connected to the external terminal 3 via the connecting portion 12. The first frame portion 9 is a rectangular plate-shaped member that is longer in the left-right direction, disposed in the center of the sealing member 2 in the left-right direction and below the external terminal 3. In addition, the first frame portion 9 is arranged so that the thickness direction is consistent with the vertical direction. The first semiconductor element 4 is fixed to the upper surface 9a of the first frame portion 9 via a bonding material 13. The bonding material 13 is made of solder with Sn as the main component. In addition, the bonding material 13 can be any material that has heat dissipation properties relative to the first semiconductor element 4, such as an adhesive material or sintering material with Ag as the main component. The connecting portion 12 is a rectangular plate-shaped member that is narrower than the width of the first frame portion 9 and the external terminal 3 in the front-back direction. The connecting portion 12 slopes downward from the right end of the external terminal 3 toward the right and connects to the first frame portion 9.

[0046] The second frame portion 10 is a rectangular plate-shaped member that is longer in the front-to-back direction, and is positioned above the first frame portion 9 and away from the right side. Furthermore, the second frame portion 10 is arranged such that its thickness direction is aligned with its vertical direction. The second frame portion 10 is longer than the first frame portion 9 in the front-to-back direction. On the upper surface 10a of the second frame portion 10, a plurality of second semiconductor elements 5 are arranged and positioned at intervals along the front-to-back direction.

[0047] The upper surface 10a of the second frame portion 10, excluding the portion where the second semiconductor element 5 is disposed, is a flat surface. On the other hand, the portion of the upper surface 10a of the second frame portion 10 where the second semiconductor element 5 is disposed is spaced apart in the front-rear direction along the left end of the upper surface 10a, i.e., the end on the side of the first frame portion 9. A downwardly recessed recess 14 is formed in the portion where the second semiconductor element 5 is disposed. Furthermore, in... Figure 3 The diagram shows the second first frame portion 9 from the front, one of a plurality of first frame portions 9 arranged in the front-rear direction, and the second frame portion 10 shows a portion including the second recess 14 from the front side. Furthermore, in... Figure 3 In the diagram, among the multiple first semiconductor elements 4 and multiple second semiconductor elements 5, only the first semiconductor element 4 and the second semiconductor element 5 located at the front are shown; the other elements are omitted from the diagram.

[0048] The spacing between adjacent recesses 14 in the front-to-back direction is approximately the same as the spacing between adjacent first frame portions 9. Each recess 14 is a rectangle slightly larger than the second semiconductor element 5 when viewed from above. Each recess 14 is open on the left side, i.e., on the side of the first frame portion 9. Each recess 14 has a rectangular bottom portion 14a that is longer in the front-to-back direction; and a side portion 14b that rises upward from the bottom portion 14a along two sides in the left-to-right direction and one side on the right side (i.e., the side opposite to the first frame portion 9) in the front-to-back direction. The depth of each recess 14 is preferably at least 10% of the thickness of the lead frame 7. Furthermore, the bottom portion 14a is located above the first frame portion 9 and above the first semiconductor element 4 mounted on the upper surface 9a of the first frame portion 9. The second semiconductor element 5 is entirely housed within the recess 14. The upper surface of the second semiconductor element 5 is positioned at the same height as, or lower than, the area on the upper surface 10a of the second frame portion 10, excluding the recess 14. The second semiconductor element 5 is fixed in the recess 14 via a bonding material 13 with its left end along the open side (left end) of the recess 14. Alternatively, a portion of the second semiconductor element 5 may protrude beyond the left side of the recess 14, that is, protrude further from the recess 14 toward the first frame portion 9, and be fixed thereas.

[0049] Next, the manufacturing method of semiconductor device 1 will be described. Figure 4This is a flowchart of a method for manufacturing semiconductor device 1. First, the lead frame 7 is prepared by processing the original board 15, including a first frame portion 9 and a second frame portion positioned above and away from the right side of the first frame portion 9 (step S1). A first semiconductor element 4 is mounted on the first frame portion 9 of the prepared lead frame 7, and a second semiconductor element 5 is mounted on the second frame portion 10 (step S2). The mounted first semiconductor element 4 and second semiconductor element 5 are connected by wire bonding (step S3). The first semiconductor element 4, the second semiconductor element 5, the first frame portion 9 and the second frame portion 10 of the lead frame 7, and the wire 6 are sealed with a sealing material (step S4).

[0050] Figure 5 and Figure 6 This is a perspective view showing a portion of the process of manufacturing the lead frame 7 of the semiconductor device 1 according to Embodiment 1. Figure 5 This illustrates the process of stamping the original plate 15 using a forming mold 16 during the preparation of the lead frame 7. Figure 6 This is a three-dimensional view showing the molding process of the recess 14.

[0051] In the lead frame preparation process (step S1) described above, firstly, the base plate 15 and the forming mold 16 are prepared. The forming mold 16 is a mold for stamping and bending the base plate 15. The forming mold 16 includes a first mold 17 on which the base plate 15 is placed and a second mold 18 which is configured opposite to the first mold 17 and moves forward and backward relative to the first mold. Figure 5 This is a perspective view showing the state in which the original plate 15 is placed on the forming mold 16. The original plate 15 is, for example, a copper plate.

[0052] The first mold 17 includes a first frame portion side receiving mold 171 corresponding to the first frame portion 9, the external terminal 3, and the connecting portion 12, and a second frame portion side receiving mold 172 corresponding to the second frame portion 10. The first frame portion side receiving mold 171 includes: a first frame portion corresponding portion 1711 with an upper surface that is rectangular and quadrangular prism-shaped, corresponding to the first frame portion 9; an external terminal corresponding portion 1712 with an upper surface that is rectangular and quadrangular prism-shaped, corresponding to the external terminal 3; and a connecting portion corresponding portion 1713 with an upper surface that is rectangular and slopes downwards towards the right, corresponding to the connecting portion. The second frame portion side receiving mold 172 is positioned above the first frame portion side receiving mold 171 and away from the right side. The upper surface 172a of the second frame portion side receiving mold 172 is a rectangle that is longer in the front-back direction. A downwardly recessed forming recess 19 for forming a forming recess 14 is provided in the portion of the upper surface 172a corresponding to the mounting portion of the second semiconductor element 5. Multiple molding recesses 19 are provided along the left end of the upper surface 172a of the second frame portion receiving mold 172 in the front-rear direction. When viewed from above, the molding recesses 19 have a larger dimension than the second semiconductor element 5. The depth of the molding recesses 19 is preferably at least 10% of the thickness of the lead frame 7.

[0053] The second mold 18 is a convex shape obtained by stamping the original plate 15 placed on the first mold 17 along the periphery of the first frame-side receiving mold 171 and the second frame-side receiving mold 172 of the first mold 17, and bending the original plate 15 in such a way that it is shaped along the upper surface of each of these receiving molds 171 and 172. In the second mold 18, at the location corresponding to the forming recess 19, a forming protrusion 20 for forming the recess 14 protrudes downward. Multiple forming protrusions 20 are provided in the front-rear direction in a manner corresponding to the forming recess 19. When viewed from above, the forming protrusion 20 has a larger size than the second semiconductor element 5, but a smaller size than the forming recess 19.

[0054] In the lead frame preparation process (step S1) described above, a raw plate 15 with an area larger than the first mold 17 is placed on the first mold 17, and the second mold 18 is moved downward from above to press the raw plate 15, thereby forming the lead frame 7. On the formed second frame portion 10, a recess 14 is formed that is located above the first frame portion 9, faces the first frame portion 9 and opens to the left, and is recessed downward.

[0055] In the semiconductor element mounting process (step S2) described above, two first semiconductor elements 4 are arranged and mounted on the first frame portion 9 in the left-right direction, and one second semiconductor element 5 is mounted in the recess 14 of the second frame portion 10. By mounting the second semiconductor element 5 in the recess 14, the second semiconductor element 5 is less likely to shift position. The second semiconductor element 5 is fixed in the recess 14 with its left end located at the open side end of the recess 14, that is, the left end of the recess 14.

[0056] In the connection process described above (step S3), the first semiconductor element 4 and the second semiconductor element 5 are connected by the wire 6b. The second semiconductor element 5 is fixed in the downwardly recessed portion 14 of the second frame portion 10, and is fixed in a position positioned along the open side end of the recess 14, thereby shortening the physical distance to the first semiconductor element 4 in both the vertical and horizontal directions. This shortens the length of the wire 6b.

[0057] In the sealing process described above (step S4), an insulating sheet 8 is placed on the lower side of the first frame portion 9, the first semiconductor element 4 and the second semiconductor element 5 are mounted thereon, and a lead frame 7, which is in a state where the first semiconductor element 4 and the second semiconductor element 5 are connected by a wire 6b, is placed in a cavity (not shown) for transfer molding, and resin as a sealing material is injected. At this time, although the stress of the sealing material acts on the wire 6b, the deformation of the wire 6b can be suppressed because the length of the wire 6b is shortened.

[0058] As described above, the first frame portion 9, on which the first semiconductor element 4 is fixed, and the second frame portion 10, on which the second semiconductor element 5 is fixed, are separated in the vertical and horizontal directions. On the other hand, the second semiconductor element 5 is disposed on the upper surface 10a of the second frame portion 10 and fixed in the recess 14 located on the upper side of the first frame portion 9.

[0059] Therefore, while ensuring the insulation distance between the first semiconductor element 4 and the second semiconductor element 5, the physical distance between them in the vertical direction can be shortened. Consequently, the length of the wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5 can be shortened, reducing the stress acting on the wire 6b during molding and suppressing deformation of the wire 6b. Furthermore, by fixing the second semiconductor element 5 in the recess 14, the position of the second semiconductor element 5 can be fixed, suppressing positional displacement when the second semiconductor element 5 is mounted.

[0060] Furthermore, a recess 14 is provided at the left end of the upper surface 10a of the second frame portion 10 and opens to the left. The second semiconductor element 5 is fixed with its left end along the open end of the recess 14.

[0061] This shortens the physical distance between the first semiconductor element 4 and the second semiconductor element 5 in the left-right direction. Therefore, it further shortens the length of the wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5.

[0062] Implementation method 2.

[0063] Figure 7 This is a perspective view showing the main parts within the semiconductor device 200 according to Embodiment 2. Figure 8 This is a front view of the recess 21 in the second frame portion 10 of the semiconductor device 200 according to Embodiment 2. Figure 9 This is a top view of the recess 21 in the second frame portion 10 of the semiconductor device 200 according to Embodiment 2. Figure 10 This is a perspective view showing the process of manufacturing the lead frame 7 of the semiconductor device 200 according to Embodiment 2. Furthermore, in the semiconductor device 200 according to Embodiment 2, parts that are the same as or similar to those in the semiconductor device 1 according to Embodiment 1 are labeled with the same symbols. The following description focuses on the points that differ from Embodiment 1.

[0064] like Figure 7 , Figure 8 and Figure 9 As shown, a pair of support portions 22, separated from each other in the front-rear direction, are provided in the recess 21. The pair of support portions 22 are respectively provided at the front and rear sides of the recess 21. Each support portion 22 is formed by bending a rectangular plate portion. Each support portion 22 has a side portion 22a that slopes inward and downward from the front or rear side of the recess 21 in the front-rear direction, and a bottom portion 22b that extends inward in the front-rear direction from the lower end of the side portion 22a. Therefore, the side portion 22a slopes upward away from the bottom portion 22b. Furthermore, the bottom portions 22b of the pair of support portions 22 are separated from each other. The side portions 22a of the pair of support portions 22 are not connected to other parts of the second frame portion 10 on the left and right sides. Therefore, the pair of support portions 22 are open on the left and right sides. The distance between the lower ends of the pair of side portions 22a in the front-rear direction is set to be slightly larger than the width of the second semiconductor element 5 in the front-rear direction. On the other hand, the spacing between the pair of bottom portions 22b in the front-to-back direction is set to be smaller than the width of the second semiconductor element 5 in the front-to-back direction. The second semiconductor element 5 is fixed to the side portion 22a and the bottom portion 22b via a bonding material 13. Figure 9 As shown, the left end of the second semiconductor element 5 is fixed along the left end of the bottom surface 22b. Alternatively, the second semiconductor element 5 may be fixed only to the bottom surface 22b. Furthermore, the left end of the second semiconductor element 5 may protrude further to the left than the left end of the bottom surface 22b and be fixed thereas.

[0065] Next, the manufacturing method of the semiconductor device 200 will be described. Furthermore, since the difference from the manufacturing method in Embodiment 1 lies in the lead frame preparation step (step S1), this will be the focus of the description. Figure 10 As shown, the molding recess 19 of the first mold 17 is composed of a pair of recessed structures 23 arranged in the front-rear direction. On the upper surface of each recessed structure 23, there are inclined surfaces corresponding to the side surface 22a and bottom surface 22b of the support portion 22, and a flat surface perpendicular to the vertical direction, respectively. The molding protrusion 20 of the second mold 18 has a protrusion structure 24 disposed opposite to the recessed structures 23 of the first mold 17. On the lower surface of the protrusion structure 24, there are inclined surfaces corresponding to the side surface 22a and bottom surface 22b of the support portion 22, and a flat surface perpendicular to the vertical direction, respectively. Between the pair of flat surfaces on the lower surface of the protrusion structure 24, a cutout 24a protruding downwards from the flat surface is formed. In the lead frame preparation process (step S1) described above, by advancing the forming protrusion 20 towards the lower surface of the recessed structure 23 of the forming recess 19, the portion of the original plate 15 other than the pair of support portions 22 is stamped to form a pair of support portions 22. Furthermore, in the mounting process (step S2) described above, bonding material 13 is applied to the bottom surface 22b of the support portion 22, and bonding material 13 is also applied to the side surface 22a that slopes upward away from the bottom surface 22b, and the second semiconductor element 5 is mounted. Alternatively, bonding material 13 may be applied only to the bottom surface 22b, and when the second semiconductor element 5 is mounted, the bonding material 13 may be pressed open and positioned between the side surface 22a and the second semiconductor element 5.

[0066] Therefore, the pair of support portions 22 are spaced apart in the front-to-back direction. This allows the bottom portion 22b to be positioned on the lower side, compared to the case where the pair of support portions 22 are connected in the front-to-back direction. This shortens the physical distance between the first semiconductor element 4 and the second semiconductor element 5. Furthermore, since the side portion 22a slopes upwards away from the bottom portion 22b, it is easier to apply the bonding material 13 to the side portion 22a, thereby improving the bonding strength between the second semiconductor element 5 and the recess 21.

[0067] Implementation method 3.

[0068] Figure 11 This is a perspective view showing the main parts within the semiconductor device 300 according to Embodiment 3. Figure 12 This is a front view of the recess 21 in the second frame portion 10 of the semiconductor device 300 according to Embodiment 3. Figure 13 This is a top view of the recess 21 in the second frame portion 10 of the semiconductor device 300 according to Embodiment 3. Figure 14 This is a perspective view showing the process of manufacturing the lead frame 7 of the semiconductor device 300 according to Embodiment 3. Furthermore, in the semiconductor device 300 according to Embodiment 3, parts that are the same as or similar to those in the semiconductor device 200 according to Embodiment 2 are labeled with the same symbols. The following description focuses on the points that differ from Embodiment 2.

[0069] like Figure 11 , Figure 12 and Figure 13 As shown, a positioning portion 25 is provided in the recess 21 on the side opposite to the open side. The positioning portion 25 is located between and away from the pair of support portions 22 in the front-rear direction. The positioning portion 25 has a side portion 25a that slopes downward from the right side of the recess 21 to the left, and a bottom portion 25b that bends and extends to the left from the lower end of the side portion 25a. The bottom portion 25b is at the same height as the bottom portion 22b of the support portion 22. The left side of the bottom portion 25b of the positioning portion 25 is located to the right of the left side of the bottom portion 22b of the support portion 22. The distance in the left-right direction from the right side of the upper surface of the bottom portion 25b to the left side of the bottom portion 22b is the same as the width of the second semiconductor element 5 in the left-right direction. The second semiconductor element 5 is placed on the bottom portion 22b of the pair of support portions 22 and the bottom portion 25b of the positioning portion 25, and is fixed in the recess 21 in a state of contact with the bent portion of the positioning portion 25. The left end of the second semiconductor element 5 is fixed along the left end of the bottom part 22b of the support portion 22.

[0070] Next, the manufacturing method of the semiconductor device 300 will be described. Furthermore, since the difference from the manufacturing method in Embodiment 2 lies in the lead frame preparation step (step S1), this will be the focus of the description. Figure 14As shown, the molding recess 19 of the first mold 17 is composed of a pair of recessed structures 23 arranged in the front-to-back direction and an intermediate recessed structure 26 disposed between the recessed structures 23. On the upper surface of each recessed structure 23, an inclined surface corresponding to the side surface 22a and bottom surface 22b of the support portion 22 and a flat surface perpendicular to the vertical direction are formed, respectively. On the upper surface of the intermediate recessed structure 26, an inclined surface corresponding to the side surface 25a and bottom surface 25b of the positioning portion 25 and a flat surface perpendicular to the vertical direction are formed, respectively. The molding protrusion 20 of the second mold 18 is composed of three protrusion structures 24 and 27 arranged in the front-to-back direction. A protrusion structure 24 is provided at a position corresponding to the recessed structure 23 of the first mold 17. On the lower surface of the protrusion structure 24, an inclined surface corresponding to the side surface 22a and bottom surface 22b of the support portion 22 and a flat surface perpendicular to the vertical direction are formed, respectively. A cutout 24a is provided at the inner and right ends of the lower surface of the convex structure 24 in the front-rear direction, protruding below a flat surface perpendicular to the vertical direction. Each cutout 24a is located in the gap between the recessed structure 23 and the intermediate recessed structure 26 of the forming recess 19 in the front-rear direction. The intermediate convex structure 27 has a lower surface corresponding to the upper surface of the intermediate recessed structure 26. Furthermore, the left end of the intermediate convex structure 27 protrudes downward to the same extent as the cutout 24a. In the lead frame preparation process (step S1) described above, the forming convex 20 moves toward the forming recess 19 and downward, thereby stamping the portion of the original plate 15 except for the pair of support portions 22 and the positioning portion 25 to form the pair of support portions 22 and the positioning portion 25.

[0071] As described above, the second semiconductor element 5 comes into contact with the positioning portion 25 provided at the right end of the recess 21. This prevents the second semiconductor element 5 from shifting position away from the first frame portion 9. Consequently, it prevents the length of the wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5 from increasing.

[0072] Implementation method 4.

[0073] Figure 15 This is a perspective view showing the main parts within the semiconductor device 400 according to Embodiment 4. Figure 16 This is a cross-sectional view showing the semiconductor device 400 according to Embodiment 4. Figure 17 This is a front view of the recess 21 in the second frame portion 10 of the semiconductor device 400 according to Embodiment 4. Figure 18 This is a perspective view showing the process of manufacturing the lead frame 7 of the semiconductor device 400 according to Embodiment 4. Figure 19 This illustrates the process of manufacturing the lead frame 7 of the semiconductor device 400 according to Embodiment 4. Figure 18 The BB line cross-sectional view is shown in the figure. Furthermore, in the semiconductor device 400 according to Embodiment 4, the same symbols are used for parts that are the same as or similar to those in the semiconductor device 200 according to Embodiment 2. The following description focuses on the points that differ from Embodiment 2.

[0074] like Figure 15 , Figure 16 and Figure 17 As shown, a pair of support portions 22 separated in the front-rear direction and a recess upper surface portion 28 located between the two support portions 22 are provided in the recess 21. The pair of support portions 22 are provided at both ends of the right side portion of the recess 21 in the front-rear direction. Each support portion 22 is formed by bending a rectangular plate portion. Each support portion 22 has a side portion 22a that slopes to the left and downward from the front-rear end of the right side portion of the recess 21, and a bottom portion 22b that extends to the left from the lower end of the side portion 22a. Therefore, the side portion 22a slopes upward away from the bottom portion 22b. The recess upper surface portion 28 is provided separately from the pair of support portions 22. The recess upper surface portion 28 is a rectangular plate portion that is longer in the front-rear direction and extends to the left from the center of the right side portion of the recess 21 in the front-rear direction. The distance between the recess upper surface portion 28 and the bottom portion 22b of the pair of support portions 22 in the vertical direction is set to be slightly larger than the vertical dimension of the second semiconductor element 5. The second semiconductor element 5 is clamped and fixed in the vertical direction by the upper surface portion 28 of the recess and the bottom portion 22b of the support portion 22, with the left end of the second semiconductor element 5 located to the left of the recess 21. The second semiconductor element 5 is fixed in the recess 21 without bonding material. The second semiconductor element 5 is entirely housed within the recess 21, with its upper surface located below the upper surface portion 28 of the recess. The wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5 is connected to the second semiconductor element 5 in the area of ​​its upper surface other than the upper surface portion 28 of the recess. Figure 15 and Figure 16 The state of the wire 6b being connected to the front region of the recessed upper surface portion 28 in the upper surface of the second semiconductor element 5 is shown.

[0075] Next, the manufacturing method of the semiconductor device 400 will be described. Furthermore, since the lead frame preparation process and the process of mounting the second semiconductor element 5 are different from those in Embodiment 2, the description will focus on these aspects. Figure 18 and Figure 19As shown, the molding recess 19 of the first mold 17 is composed of a pair of recessed structures 23 arranged in the front-rear direction and an intermediate recessed structure 26 disposed between the pair of recessed structures 23. The upper surface of the recessed structure 23 is located at a lower position than the intermediate recessed structure 26. On the upper surface of each recessed structure 23, there are inclined surfaces corresponding to the side surface 22a and bottom surface 22b of the support portion 22, and a flat surface perpendicular to the vertical direction, respectively. The molding protrusion 20 of the second mold 18 is composed of a pair of protrusion structures 24 arranged in the front-rear direction. The protrusion structure 24 is provided at a position corresponding to the recessed structure 23 of the first mold 17. On the lower surface of the protrusion structure 24, there are inclined surfaces corresponding to the side surface 22a and bottom surface 22b of the support portion 22, and a flat surface perpendicular to the vertical direction, respectively. At the front and rear ends of the lower surface of the protrusion structure 24, there are cutouts 24a protruding below other parts of the lower surface. In the stamping process of the lead frame preparation process (step S1), the forming protrusion 20 is advanced to below the three components of the forming recess 19, thereby bending the original plate 15 by the protrusion structure 24 to form the support portion 22, and the portion between the two support portions 22 on the original plate 15 is not processed and is retained, thereby forming the upper surface portion 28 of the recess. In the semiconductor element mounting process (step S2), the second semiconductor element 5 is inserted from the left side of the recess 21 between the upper surface portion 28 of the recess and the bottom portion 22b of the support portion 22, and the second semiconductor element 5 is clamped and fixed from the top and bottom by the upper surface portion 28 and the bottom portion 22b of the recess.

[0076] As described above, the second semiconductor element 5 clamps and fixes the bottom portion 22b of the support portion 22 and the upper surface portion 28 of the recess in the vertical direction, thereby allowing the second semiconductor element 5 to be fixed in the recess 21 without the need for bonding material. This eliminates the need for bonding material and consequently eliminates the heating process required for hardening the bonding material. Therefore, the manufacturing time of the semiconductor device 400 can be reduced.

[0077] The preferred embodiments have been described in detail above, but are not limited to the above embodiments. Various modifications and substitutions can be made to the above embodiments without departing from the scope of the claims.

[0078] Figure 20This diagram illustrates a variation of Embodiment 1. The second semiconductor element 5, while maintaining an insulating distance from the first semiconductor element 4, can be fixed within the recess 14 while protruding to the left from the left end. This further shortens the length of the wire 6b. Furthermore, in Embodiments 2 to 4, the second semiconductor element 5 can also be fixed within the recess 21 while protruding to the left side of the left end of the recess 21. Moreover, when the second semiconductor element 5 is fixed in the protruding state as described above, from the perspective of the bonding strength with the second semiconductor element 5, it is preferable that the side portion 14b of the recess 14 or the side portion 22a of the support portion 22 is inclined. Figure 20 The side portion 14b of the recess 14 is shown to be inclined. Alternatively, the recess 14 may also have an upwardly raised side portion along its entire periphery.

[0079] In embodiments 2 to 4, examples of providing two support portions 22 are shown, but the embodiments are not limited to this, and three or more support portions may also be provided.

[0080] In the above embodiment, the first frame portion 9 and the second frame portion 10 are disposed on a lead frame 7, but the first frame portion 9 and the second frame portion 10 may also be disposed separately. For example, the first frame portion 9 may be made of an insulating substrate and the second frame portion 10 may be made of a metal component.

[0081] The various methods disclosed herein are summarized and recorded below as appendices.

[0082] (Note 1) A semiconductor device, comprising:

[0083] First semiconductor element;

[0084] A second semiconductor element, which is connected to the first semiconductor element;

[0085] A wire connecting the first semiconductor element and the second semiconductor element;

[0086] A first frame portion, wherein the first semiconductor element is disposed;

[0087] A second frame portion, which is positioned above the first frame portion and disposed away from it in the left-right direction, and is provided with the second semiconductor element; and

[0088] A sealing member that seals the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and the wire.

[0089] A downwardly recessed portion is provided on the upper surface of the second frame portion.

[0090] The recess is located on the upper side of the first frame portion.

[0091] The second semiconductor element is fixed in the recess.

[0092] (Note 2) The semiconductor device as described in Note 1,

[0093] The recess is provided on the end edge of the first frame portion on the upper surface of the second frame portion and is open to the first frame portion.

[0094] (Note 3) The semiconductor device as described in Note 2,

[0095] The second semiconductor element is fixed in the recess with its end located at the open side of the recess, or with its protrusion extending further toward the first frame portion than the open side of the recess.

[0096] (Note 4) The semiconductor device as described in any one of Notes 1 to 3,

[0097] The recess has a bottom portion and a side portion that slopes upwards away from the bottom portion.

[0098] The second semiconductor element is fixed to the bottom surface and the side surface via a bonding material.

[0099] (Note 5) The semiconductor device as described in any one of Notes 2 to 4,

[0100] The recess is provided with a plurality of support portions that are separated from each other in a front-back direction intersecting the left-right direction and support the second semiconductor element.

[0101] Each of the support portions has a bottom portion and a side portion extending upward from the bottom portion and connecting to the periphery of the recess in the second frame portion.

[0102] The second semiconductor element is fixed on the plurality of the support portions.

[0103] (Note 6) The semiconductor device as described in Note 5,

[0104] The recess has a positioning portion located in the left-right direction on the side opposite to the open end of the recess.

[0105] The second semiconductor element is in contact with the positioning part.

[0106] (Note 7) The semiconductor device as described in Note 5,

[0107] The recess has an upper surface portion located on the upper side of the bottom portion.

[0108] The second semiconductor element is clamped and fixed by the bottom part and the top part.

[0109] (Appendix 8) A method for manufacturing a semiconductor, comprising:

[0110] Preparation process for the first frame part and the second frame part located above the first frame part and far away in the left and right direction;

[0111] The mounting process of mounting a first semiconductor element on the first frame portion and mounting a second semiconductor element on the second frame portion;

[0112] The connection process of connecting the first semiconductor element and the second semiconductor element by means of a wire; and

[0113] The sealing process of sealing the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and the wire with a sealing material.

[0114] In the preparation process, a first mold having a forming recess, a second mold having a forming protrusion corresponding to the forming recess and arranged opposite to the forming recess and movable relative to the first mold, and a base plate for the second frame portion are prepared.

[0115] The original plate is placed in the region containing the forming recess in the first mold.

[0116] By advancing the second mold towards the first mold and stamping the original plate, the second frame portion is formed, creating a downwardly recessed portion on the formed second frame portion located above the first frame portion.

[0117] In the mounting process,

[0118] The second semiconductor element is fixed in the recess.

[0119] Label Explanation

[0120] 1, 200, 300, 400 Semiconductor device; 2 Sealing member; 4 First semiconductor element; 5 Second semiconductor element; 6b Wire; 9 First frame portion; 10 Second frame portion; 10a Upper surface of the second frame portion; 14, 21 Recess; 14a Bottom surface of the recess; 14b Side surface of the recess; 15 Original plate; 16 Molding mold; 17 First mold; 18 Second mold; 22 Support portion; 22a Side surface; 22b Bottom surface; 25 Positioning portion; 25a Side surface; 25b Bottom surface; 28 Upper surface of the recess.

Claims

1. A semiconductor device, characterized in that, include: First semiconductor element; A second semiconductor element, which is connected to the first semiconductor element; A wire connecting the first semiconductor element and the second semiconductor element; A first frame portion, wherein the first semiconductor element is disposed; The second frame portion is located above the first frame portion and is disposed far apart in the left-right direction, and is provided with the second semiconductor element; as well as A sealing member that seals the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and the wire. A downwardly recessed portion is provided on the upper surface of the second frame portion. The recess is located on the upper side of the first frame portion. The second semiconductor element is fixed in the recess.

2. The semiconductor device as claimed in claim 1, characterized in that, The recess is provided on the end edge of the first frame portion on the upper surface of the second frame portion and is open to the first frame portion.

3. The semiconductor device as claimed in claim 2, characterized in that, The second semiconductor element is fixed in the recess with its end located at the open side of the recess, or with its protrusion extending further toward the first frame portion than the open side of the recess.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that, The recess has a bottom portion and a side portion that slopes upwards away from the bottom portion. The second semiconductor element is fixed to the bottom surface and the side surface via a bonding material.

5. The semiconductor device as claimed in claim 2 or 3, characterized in that, The recess is provided with a plurality of support portions that are separated from each other in a front-back direction intersecting the left-right direction and support the second semiconductor element. Each of the support portions has a bottom portion and a side portion extending upward from the bottom portion and connecting to the periphery of the recess in the second frame portion. The second semiconductor element is fixed on the plurality of the support portions.

6. The semiconductor device as claimed in claim 5, characterized in that, The recess has a positioning portion located in the left-right direction on the side opposite to the open end of the recess. The second semiconductor element is in contact with the positioning part.

7. The semiconductor device as claimed in claim 5, characterized in that, The recess has an upper surface portion located on the upper side of the bottom portion. The second semiconductor element is clamped and fixed by the bottom part and the top part.

8. A method for manufacturing a semiconductor, characterized in that, include: Preparation process for the first frame part and the second frame part located above the first frame part and far away in the left and right direction; The mounting process of mounting a first semiconductor element on the first frame portion and mounting a second semiconductor element on the second frame portion; The connection process of connecting the first semiconductor element and the second semiconductor element by means of a wire; and The sealing process of sealing the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and the wire with a sealing material. In the preparation process, Prepare a first mold having a forming recess, a second mold having a forming protrusion corresponding to the forming recess and configured opposite to the forming recess and movable forward and backward relative to the first mold, and a base plate for the second frame portion. The original plate is placed in the region containing the forming recess in the first mold. By advancing the second mold towards the first mold and stamping the original plate, the second frame portion is formed, creating a downwardly recessed portion on the formed second frame portion located above the first frame portion. In the mounting process, The second semiconductor element is fixed in the recess.

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