Semiconductor device and method for manufacturing a semiconductor device

Abstract

The present invention provides a semiconductor device and a method for manufacturing a semiconductor device that can suppress deformation of wires connecting semiconductor elements while maintaining the insulating distance between semiconductor elements in a semiconductor device sealed with a sealing material. [Solution] The device comprises 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 on which the first semiconductor element 4 is provided, a second frame portion 10 positioned above and separated from the first frame portion 9 in the left-right direction, on which the second semiconductor element 5 is provided, and a sealing member 2. The upper surface 10a of the second frame portion 10 is provided with a recess 14 that 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] The present disclosure relates to a semiconductor device and a method of manufacturing a semiconductor device.

Background Art

[0002] Patent Document 1 discloses an example of a resin-sealed power semiconductor device. In this semiconductor device, a power semiconductor element is provided on the upper surface of a die pad, and a thick film substrate is joined via a bonding layer on a plurality of support inner leads among inner leads located above the die pad. All of the control circuit patterns of the power semiconductor element are formed as thick film patterns on the upper surface of the thick film substrate, and semiconductor elements for the control circuit are mounted on the thick film patterns via solder. The electrode of the power semiconductor element and the thick film pattern are electrically connected by a wire. Since the support inner lead is located above the die pad, an insulation distance between the power semiconductor element provided on the die pad and the semiconductor element on the support inner lead is maintained. Therefore, the wire has a length necessary to maintain the insulation distance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The resin-sealed power semiconductor device of Patent Document 1 is manufactured, for example, by transfer molding. At the time of this molding, a sealing material such as resin is injected between both semiconductor elements. On the other hand, an elongated wire having a length necessary to maintain an insulation distance is provided between both semiconductor elements. Therefore, stress may act on the wire due to the sealing material injected between both semiconductor elements at the time of molding, and the wire may be deformed.

[0005] This disclosure is made to solve the above problems and aims to provide a semiconductor device and a method for manufacturing a semiconductor device that can suppress deformation of wires connecting semiconductor elements while maintaining the insulation distance between semiconductor elements in a semiconductor device sealed with a sealing material. [Means for solving the problem]

[0006] The semiconductor device according to this disclosure comprises 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 provided, a second frame portion arranged above and apart from the first frame portion in the left-right direction, on which the second semiconductor element is provided, and a sealing member that seals the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion and the wire, wherein the upper surface of the second frame portion is provided with a recess that is recessed downward, the recess is located above the first frame portion, and the second semiconductor element is fixed in the recess.

[0007] A method for manufacturing a semiconductor device according to the present disclosure comprises a preparation step of preparing a first frame portion and a second frame portion provided above the first frame portion and at a position separated from it in the left-right direction; a mounting step of mounting a first semiconductor element on the first frame portion and a second semiconductor element on the second frame portion; a connection step of connecting the first semiconductor element and the second semiconductor element with a wire; and a sealing step 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, wherein in the preparation step, a first mold having a molding recess, a second mold positioned opposite the molding recess and moving forward and backward relative to the first mold and having a molding protrusion corresponding to the molding recess, and a base plate for the second frame portion are prepared, the base plate is placed in the region of the first mold including the molding recess, the second mold advances toward the first mold and punches out the base plate to form the second frame portion, and a recess is formed in the formed second frame portion that is recessed downward and located above the first frame portion. In the mounting process described above, the second semiconductor element is fixed in the recess. [Effects of the Invention]

[0008] According to the semiconductor device and method for manufacturing a semiconductor device described herein, in a semiconductor device sealed with a sealing material, deformation of wires can be suppressed while maintaining the insulation distance between semiconductor elements. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a semiconductor device according to Embodiment 1. [Figure 2] This is a cross-sectional view of the semiconductor device according to Embodiment 1. [Figure 3] This is a perspective view showing the main parts of the semiconductor device according to Embodiment 1. [Figure 4] This is a flowchart showing the method for manufacturing a semiconductor device according to Embodiment 1. [Figure 5] This is a perspective view showing the process for manufacturing the lead frame of a semiconductor device according to Embodiment 1. [Figure 6] It is a perspective view showing the process of manufacturing a lead frame of a semiconductor device according to Embodiment 1. [Figure 7] It is a perspective view showing a main part in a semiconductor device according to Embodiment 2. [Figure 8] It is a front view of a recess in the second frame portion of a semiconductor device according to Embodiment 2. [Figure 9] It is a plan view of a recess in the second frame portion of a semiconductor device according to Embodiment 2. [Figure 10] It is a perspective view showing the process of manufacturing a lead frame of a semiconductor device according to Embodiment 2. [Figure 11] It is a perspective view showing a main part in a semiconductor device according to Embodiment 3. [Figure 12] It is a front view of a recess in the second frame portion of a semiconductor device according to Embodiment 3. [Figure 13] It is a plan view of a recess in the second frame portion of a semiconductor device according to Embodiment 3. [Figure 14] It is a perspective view showing the process of manufacturing a lead frame of a semiconductor device according to Embodiment 3. [Figure 15] It is a perspective view showing a main part in a semiconductor device according to Embodiment 4. [Figure 16] It is a cross-sectional view of a semiconductor device according to Embodiment 4. [Figure 17] It is a front view of a recess in the second frame portion of a semiconductor device according to Embodiment 4. [Figure 18] It is a perspective view showing the process of manufacturing a lead frame of a semiconductor device according to Embodiment 4. [Figure 19] It is a cross-sectional view showing the process of manufacturing a lead frame of a semiconductor device according to Embodiment 4. [Figure 20] It is a cross-sectional view showing a modification example of a semiconductor device according to Embodiment 1.

Embodiments for Carrying Out the Invention

[0010] In the following description, terms indicating directions such as "up" and "down" are used. However, the directions such as "up" and "down" indicate relative orientations in the semiconductor device and do not limit the directions during the manufacturing or use of the semiconductor device.

[0011] Embodiment 1. Embodiment 1 of the present disclosure will be described below with reference to the drawings. FIG. 1 is a perspective view showing a semiconductor device 1 according to Embodiment 1. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1 showing the cross-section of the semiconductor device 1.

[0012] As shown in FIG. 1, 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 in the shape of a rectangular plate made of resin. The external terminals 3 are arranged side by side in the front-rear direction on the left side surface 2a and the right side surface 2b of the sealing member 2. Each external terminal 3 extends outward in the left-right direction from the side surfaces 2a, 2b of the sealing member 2 and bends at a substantially right angle and extends upward. The external terminals 3 are mounted on a control board having a control circuit (not shown) and are electrically connected to the outside of the semiconductor device 1. As shown in FIG. 2, inside the sealing member 2, a first semiconductor element 4, a second semiconductor element 5, a wire 6, a lead frame 7, and an insulating sheet 8 are provided. Note that FIG. 2 does not show the portion bent upward of the external terminal 3.

[0013] FIG. 3 is a perspective view showing the main part inside the semiconductor device 1, showing the first semiconductor element 4, the second semiconductor element 5, the wire 6, and the lead frame 7.

[0014] The first semiconductor element 4 is made of Si and is a so-called power semiconductor element that controls power. The first semiconductor element 4 is, for example, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or an FWD (Free Wheeling Diode). The length of one side of the first semiconductor element 4 is, for example, about 3 mm to 13 mm. The first semiconductor element 4 is not limited to Si, but may 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.

[0015] The second semiconductor element 5 is an integrated circuit (IC) that controls the first semiconductor element 4, and is, for example, an HVIC (High Side Gate Driver) and an 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 by wires 6. The size of the second semiconductor element 5 is smaller than, for example, IGBTs and MOSFETs, and because of the small current value used for control, it is wired and connected using the ball bonding method with wires 6.

[0016] Wire 6 can be any metal, such as pure Al or a conductive metal mainly composed of Al. Wire 6 includes wire 6a, which connects the first semiconductor element 4 to the lead frame 7, and wire 6b, which connects the first semiconductor element 4 to the second semiconductor element 5. If the first semiconductor element 4 is an IGBT, wire 6a connects the collector electrode on the top surface of the IGBT to the lead frame 7. If 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, with a diameter of, for example, 200 μm to 400 μm for wire 6a and a diameter of, for example, 30 μm to 60 μm for wire 6b.

[0017] The lead frame 7 is mounted with a first semiconductor element 4 and a second semiconductor element 5 connected to the first semiconductor element 4, and a circuit is formed within the semiconductor device 1 by wiring connections of wires 6b. The thickness of the lead frame 7 is, for example, about 0.3 to 1.0 mm. The lead frame 7 and external terminals 3 are formed from a single sheet of metal. The lead frame 7 and external terminals 3 have a stepped structure, obtained by cutting and forming a single sheet of metal using a mold. The material of the lead frame 7 and external terminals 3 is a conductive metal material mainly composed of Cu, or preferably a material that is conductive and also has heat dissipation properties, for example, an alloy such as Cu-Mo may be used.

[0018] The lead frame 7 includes a first frame portion 9 on which the first semiconductor element 4 is provided, and a second frame portion 10 which is provided with the second semiconductor element 5, and is positioned above the first frame portion 9 and separated from it in the left-right direction (to the right in this embodiment).

[0019] Multiple first frame portions 9 are arranged within the sealing member 2, and these first frame portions 9 are aligned in the front-to-back direction in the left-to-right center of the sealing member 2. The first frame portions 9 are the die pad portions of the lead frame 7. An insulating sheet 8 is provided on the lower surface of the first frame portions 9 for electrical insulation. The insulating sheet 8 may be sandwiched between the upper first frame portion 9 and the lower heat sink 11. In that case, a portion of the heat sink 11 is exposed from the sealing member 2. An insulating substrate may be used for the first frame portions 9. In that case, the second frame portion 10 may be a metal terminal that replaces the lead frame 7, and the second semiconductor element 5 may be mounted on the metal terminal.

[0020] The first frame portion 9 is connected to the external terminal 3 via a connecting portion 12. The first frame portion 9 is a rectangular plate member that is long in the left-right direction and is located in the left-right center of the sealing member 2, below the external terminal 3. The first frame portion 9 is also positioned so that its thickness direction coincides with the up-down 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 material of the bonding material 13 is, for example, a solder material mainly composed of Sn. The bonding material 13 can be any material that has heat dissipation properties for the first semiconductor element 4, such as an adhesive or sintered material mainly composed of Ag. The connecting portion 12 is a rectangular plate member that is narrower in the front-to-back direction than the first frame portion 9 and the external terminal 3. 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.

[0021] The second frame portion 10 is a rectangular plate member that is long in the front-to-back direction and is positioned above and to the right of the first frame portion 9. The second frame portion 10 is also positioned so that its thickness direction coincides with the vertical direction. The second frame portion 10 is longer in the front-to-back direction than the first frame portion 9. Multiple second semiconductor elements 5 are arranged on the upper surface 10a of the second frame portion 10, spaced apart in the front-to-back direction.

[0022] The upper surface 10a of the second frame portion 10 is flat in all areas except for the portion where the second semiconductor element 5 is installed. On the other hand, the portion of the upper surface 10a of the second frame portion 10 where the second semiconductor element 5 is installed is provided at intervals in the front-rear direction along the left end of the upper surface 10a, that is, the end on the first frame portion 9 side. A recessed portion 14 that is recessed downwards is formed in the portion where the second semiconductor element 5 is installed. In Figure 3, the first frame portions 9 up to the second from the front are shown among the multiple first frame portions 9 arranged in the front-rear direction, and the second frame portion 10 is shown including the second recessed portion 14 from the front. Also in Figure 3, only the first semiconductor element 4 and the second semiconductor element 5 located at the very front are shown among the multiple first semiconductor elements 4 and multiple second semiconductor elements 5, and the other elements are omitted from the illustration.

[0023] 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 rectangular in shape, slightly larger than the second semiconductor element 5 in a plan view. Each recess 14 is open to the left side, i.e., to the first frame portion 9 side. Each recess 14 has a rectangular bottom portion 14a that is long in the front-to-back direction, and a side portion 14b that rises upward from two sides of the bottom portion 14a that extend in the left-to-right direction and one side that extends in the front-to-back direction on the right side (i.e., opposite to the first frame portion 9). 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 even 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, and the upper surface of the second semiconductor element 5 is at the same height as or lower than the area on the upper surface 10a of the second frame portion 10 other than the recess 14. The second semiconductor element 5 is fixed to the recess 14 via a bonding material 13, with its left end aligned with the open end (left end) of the recess 14. Alternatively, a portion of the second semiconductor element 5 may be fixed protruding to the left of the recess 14, that is, towards the first frame portion 9 side of the recess 14.

[0024] Next, the manufacturing method of the semiconductor device 1 will be described. Figure 4 is a flowchart of the manufacturing method of the semiconductor device 1. First, the lead frame 7 is prepared by processing the lead frame 15 to include a first frame portion 9 and a second frame portion located above and to the right of the first frame portion 9 (step S1). The first semiconductor element 4 is mounted on the first frame portion 9 of the prepared lead frame 7, and the second semiconductor element 5 is mounted on the second frame portion 10 (step S2). The mounted first semiconductor element 4 and the 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).

[0025] Figures 5 and 6 are perspective views showing part of the process for manufacturing the lead frame 7 of the semiconductor device 1 according to Embodiment 1. Figure 5 shows the process of punching out the base plate 15 with a mold 16 in the process of preparing the lead frame 7. Figure 6 is a perspective view showing the molding process of the recess 14.

[0026] In the lead frame preparation process (step S1) described above, first, the base plate 15 and the molding die 16 are prepared. The molding die 16 is a die used to punch and bend the base plate 15. The molding die 16 comprises a first die 17 on which the base plate 15 is placed, and a second die 18 positioned opposite the first die 17 and moving back and forth relative to the first die. Figure 5 is a perspective view showing the state in which the base plate 15 is placed on the molding die 16. The base plate 15 is, for example, a copper plate.

[0027] The first type 17 comprises a first frame section side receiving type 171 corresponding to the first frame section 9, the external terminal 3, and the connecting section 12, and a second frame section side receiving type 172 corresponding to the second frame section 10. The first frame section side receiving type 171 comprises a rectangular prism-shaped first frame section corresponding part 1711 whose upper surface is rectangular and corresponds to the first frame section 9, a rectangular prism-shaped external terminal corresponding part 1712 whose upper surface is rectangular and corresponds to the external terminal 3, and a connecting section corresponding part 1713 whose upper surface is rectangular and slopes downward toward the right, corresponding to the connecting section. The second frame section side receiving type 172 is provided at a position above and to the right of the first frame section side receiving type 171. The upper surface 172a of the second frame section side receiving type 172 is rectangular in shape, elongated in the front-to-back direction. A downward-recessed molding recess 19 for forming a recess 14 is provided in the portion of this upper surface 172a corresponding to the mounting location of the second semiconductor element 5. Multiple molded recesses 19 are provided in the front-rear direction along the left end of the upper surface 172a of the second frame side receiving mold 172. In plan view, the molded recesses 19 are larger in size than the second semiconductor element 5. Preferably, the depth of the molded recesses 19 is at least 10% of the thickness of the lead frame 7.

[0028] The second type 18 is a convex mold that punches out the original plate 15 placed on the first type 17 along the periphery of the first frame-side receiving die 171 and the second frame-side receiving die 172 of the first type 17, and also bends the original plate 15 to conform to the shape of the upper surfaces of these receiving dies 171 and 172. In the second type 18, a molding convex portion 20 for forming the recess 14 protrudes downward at the location corresponding to the molding recess 19. Multiple molding convex portions 20 are provided in the front-rear direction to correspond to the molding recess 19. In a plan view, the molding convex portion 20 is larger in size than the second semiconductor element 5, but smaller in size than the molding recess 19.

[0029] In the lead frame preparation process (step S1) described above, a lead plate 15 with a larger area than the first mold 17 is placed on the first mold 17, and the lead frame 7 is formed by extending the second mold 18 downwards from above and punching out the lead plate 15. The formed second frame portion 10 has a recess 14 that is located above the first frame portion 9, is open to the left of the first frame portion 9, and is recessed downwards.

[0030] In the semiconductor element mounting process (step S2) described above, two first semiconductor elements 4 are mounted side by side on the first frame portion 9, and one second semiconductor element 5 is mounted in the recess 14 of the second frame portion 10. Mounting the second semiconductor element 5 in the recess 14 makes it less likely for the second semiconductor element 5 to shift position. The second semiconductor element 5 is fixed in the recess 14 with its left end positioned at the open end of the recess 14, that is, at the left end of the recess 14.

[0031] In the above connection process (step S3), the first semiconductor element 4 and the second semiconductor element 5 are connected by a wire 6b. The second semiconductor element 5 is fixed in a recess 14 that is recessed below the second frame portion 10, and is fixed in a position along the open end of the recess 14. As a result, the physical distance between the second semiconductor element 5 and the first semiconductor element 4 is reduced in both the vertical and horizontal directions. This makes it possible to shorten the length of the wire 6b.

[0032] In the above sealing process (step S4), an insulating sheet 8 is provided on the lower side of the first frame portion 9, the first semiconductor element 4 and the second semiconductor element 5 are mounted on it, and the lead frame 7, in which the first semiconductor element 4 and the second semiconductor element 5 are connected by wire 6b, is placed in a cavity (not shown) for transfer molding, and resin, which is the sealing material, is injected. At this time, although stress from the sealing material acts on the wire 6b, deformation of the wire 6b is suppressed because the length of the wire 6b is shortened.

[0033] As described above, the first frame portion 9 to which the first semiconductor element 4 is fixed and the second frame portion 10 to which the second semiconductor element 5 is fixed are spaced apart in the vertical and horizontal directions. On the other hand, the second semiconductor element 5 is provided on the upper surface 10a of the second frame portion 10 and fixed to a recess 14 located above the first frame portion 9.

[0034] This makes it possible to reduce the vertical physical distance between the first semiconductor element 4 and the second semiconductor element 5 while maintaining the insulation distance between them. Therefore, it becomes possible to shorten the length of the wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5, reducing the stress acting on the wire 6b during molding and suppressing deformation of the wire 6b. In addition, since the second semiconductor element 5 is fixed in the recess 14, the position of the second semiconductor element 5 is fixed, and positional displacement when mounting the second semiconductor element 5 can be suppressed.

[0035] Furthermore, the recess 14 is provided at the left end of the upper surface 10a of the second frame portion 10 and is open to the left. The second semiconductor element 5 is fixed so that its left end aligns with the open end of the recess 14.

[0036] This makes it possible to reduce the physical distance between the first semiconductor element 4 and the second semiconductor element 5 in the left-right direction. Therefore, it becomes possible to further shorten the length of the wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5.

[0037] Embodiment 2. Figure 7 is a perspective view showing the main parts of the semiconductor device 200 according to Embodiment 2. Figure 8 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 is a plan view of the recess 21 in the second frame portion 10 of the semiconductor device 200 according to Embodiment 2. Figure 10 is a perspective view showing the process of manufacturing the lead frame 7 of the semiconductor device 200 according to Embodiment 2. In the semiconductor device 200 according to Embodiment 2, parts that are the same as or similar to those of the semiconductor device 1 according to Embodiment 1 are denoted by the same reference numerals, and the following description will focus on the differences from Embodiment 1.

[0038] As shown in Figures 7, 8, and 9, the recess 21 is provided with a pair of support portions 22 spaced apart from each other in the front-rear direction. The pair of support portions 22 are provided on the front and rear edges of the recess 21, respectively. Each support portion 22 is formed by bending a rectangular plate portion. Each support portion 22 has a side portion 22a that slopes downward toward the front-rear direction from the front or rear edge of the recess 21, and a bottom portion 22b that extends toward the front-rear direction from the lower end of the side portion 22a. Therefore, the side portion 22a slopes upward as it moves away from the bottom portion 22b. Also, the bottom portions 22b of the pair of support portions 22 are spaced apart 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 both the left and right sides. Therefore, the pair of support portions 22 are open on both 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 front-rear width of the second semiconductor element 5. On the other hand, the distance between the pair of bottom portions 22b in the front-to-back direction is set to be smaller than the front-to-back width of the second semiconductor element 5. The second semiconductor element 5 is fixed to the side portion 22a and the bottom portion 22b via the bonding material 13. As shown in Figure 9, the left end of the second semiconductor element 5 is fixed along the left end of the bottom portion 22b. The second semiconductor element 5 may also be fixed only to the bottom portion 22b. Furthermore, the left end of the second semiconductor element 5 may be fixed so as to protrude to the left of the left end of the bottom portion 22b.

[0039] Next, the manufacturing method of the semiconductor device 200 will be described. Note that the lead frame preparation process (step S1) differs from the manufacturing method in Embodiment 1, so this point will be explained in detail. As shown in Figure 10, the molded recess 19 of the first mold 17 is composed of a pair of recess components 23 arranged in the front-to-back direction. On the upper surface of each recess component 23, an inclined surface corresponding to the side portion 22a and the bottom portion 22b of the support portion 22, and a flat surface perpendicular to the vertical direction are formed. The molded protrusion 20 of the second mold 18 has a protrusion component 24 provided at a position opposite to the recess component 23 of the first mold 17. On the lower surface of the protrusion component 24, an inclined surface corresponding to the side portion 22a and the bottom portion 22b of the support portion 22, and a flat surface perpendicular to the vertical direction are formed. Between the pair of flat surfaces on the lower surface of the protrusion component 24, a cut portion 24a is formed that protrudes downward from the flat surface of the tower body. In the lead frame preparation step (step S1) described above, the molded protrusions 20 advance below the upper surface of the recessed component 23 of the molded recess 19, thereby punching out the portion of the original plate 15 other than the pair of support portions 22, and forming the pair of support portions 22. In the mounting step (step S2) described above, the bonding material 13 is applied to the bottom surface 22b of the support portion 22, and the bonding material 13 is also applied to the side surface 22a which slopes upward as it moves away from the bottom surface 22b, and the second semiconductor element 5 is mounted. Alternatively, the 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 spread out to interpose the bonding material 13 between the side surface 22a and the second semiconductor element 5.

[0040] As described above, the pair of support parts 22 are spaced apart from each other in the front-rear direction. This allows the bottom surface 22b to be positioned lower compared to the case where the pair of support parts 22 are connected in the front-rear direction. Therefore, the physical distance between the first semiconductor element 4 and the second semiconductor element 5 can be reduced. In addition, because the side surface 22a is inclined upward as it moves away from the bottom surface 22b, it becomes easier to apply the bonding material 13 to the side surface 22a, thereby increasing the bonding strength between the second semiconductor element 5 and the recess 21.

[0041] Embodiment 3. Figure 11 is a perspective view showing the main parts of the semiconductor device 300 according to Embodiment 3. Figure 12 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 is a plan view of the recess 21 in the second frame portion 10 of the semiconductor device 300 according to Embodiment 3. Figure 14 is a perspective view showing the process of manufacturing the lead frame 7 of the semiconductor device 300 according to Embodiment 3. In the semiconductor device 300 according to Embodiment 3, parts that are the same as or similar to those of the semiconductor device 200 according to Embodiment 2 are denoted by the same reference numerals, and the following description will focus on the differences from Embodiment 2.

[0042] As shown in Figures 11, 12, and 13, the recess 21 is provided with a positioning portion 25 on the side opposite to the open end. The positioning portion 25 is located between a pair of support portions 22 in the front-rear direction and is spaced apart from the pair of support portions 22. The positioning portion 25 has a side portion 25a that slopes downward toward the left from the right side of the recess 21, 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 located 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 fixed in the recess 21, resting on the bottom surface 22b of the pair of support parts 22 and the bottom surface 25b of the positioning part 25, and in contact with the bent part of the positioning part 25. The left end of the second semiconductor element 5 is fixed along the left end of the bottom surface 22b of the support part 22.

[0043] Next, the manufacturing method of the semiconductor device 300 will be described. Note that the lead frame preparation process (step S1) differs from the manufacturing method in Embodiment 2, so this point will be explained in detail. As shown in Figure 14, the molded recess 19 of the first mold 17 is composed of a pair of recess components 23 arranged in the front-rear direction and an intermediate recess component 26 provided between the recess components 23. The upper surface of each recess component 23 has inclined surfaces corresponding to the side portion 22a and bottom portion 22b of the support portion 22, and a flat surface perpendicular to the vertical direction. The upper surface of the intermediate recess component 26 has inclined surfaces corresponding to the side portion 25a and bottom portion 25b of the positioning portion 25, and a flat surface perpendicular to the vertical direction. The molded protrusion 20 of the second mold 18 is composed of three protrusion components 24 and 27 arranged in the front-rear direction. A protrusion component 24 is provided at a position corresponding to the recess component 23 of the first mold 17. The lower surface of the protruding portion 24 has an inclined surface and a flat surface perpendicular to the vertical direction, which correspond to the side surface 22a and bottom surface 22b of the support portion 22, respectively. The inner and right ends of the lower surface of the protruding portion 24 in the front-rear direction are provided with cut portions 24a that protrude downward from the flat surface perpendicular to the vertical direction. Each cut portion 24a is located in the front-rear direction in the gap between the recessed portion 23 and the intermediate recessed portion 26 of the molded recess 19. The intermediate protruding portion 27 has a lower surface that corresponds to the upper surface of the intermediate recessed portion 26. The left end of the intermediate protruding portion 27 also protrudes downward to the same extent as the cut portion 24a. In the lead frame preparation step (step S1) described above, the molded protrusion 20 advances downward toward the molded recess 19, punching out the portion of the original plate 15 other than the pair of support portions 22 and the positioning portion 25, thereby forming the pair of support portions 22 and the positioning portion 25.

[0044] As described above, the second semiconductor element 5 is in contact with the positioning portion 25 provided at the right end of the recess 21. This makes it possible to suppress the second semiconductor element 5 from shifting away from the first frame portion 9. Therefore, it is possible to suppress an increase in the length of the wire 6b connecting the first semiconductor element 4 and the second semiconductor element 5.

[0045] Embodiment 4. Figure 15 is a perspective view showing the main parts of the semiconductor device 400 according to Embodiment 4. Figure 16 is a diagram showing a cross-section of the semiconductor device 400 according to Embodiment 4. Figure 17 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 is a perspective view showing the process of manufacturing the lead frame 7 of the semiconductor device 400 according to Embodiment 4. Figure 19 is a cross-sectional view of the cross-sectional view along line BB of Figure 18, showing the process of manufacturing the lead frame 7 of the semiconductor device 400 according to Embodiment 4. In the semiconductor device 400 according to Embodiment 4, parts that are the same as or similar to those of the semiconductor device 200 according to Embodiment 2 are denoted by the same reference numerals, and the following description will focus on the differences from Embodiment 2.

[0046] As shown in Figures 15, 16, and 17, the recess 21 is provided with a pair of support portions 22 spaced apart from each other in the front-rear direction, and a recessed upper surface portion 28 located between the two support portions 22. The pair of support portions 22 are provided at both front-rear ends of the right side 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 downward toward the left from the front-rear end of the right side 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 as it moves away from the bottom portion 22b. The recessed upper surface portion 28 is provided spaced apart from the pair of support portions 22. The recessed upper surface portion 28 is a rectangular plate portion that is long in the front-rear direction and extends to the left from the front-rear center of the right side of the recess 21. The vertical distance between the upper surface 28 of the recess and the bottom surfaces 22b of the pair of support parts 22 is set to be slightly larger than the vertical dimension of the second semiconductor element 5. The second semiconductor element 5 is fixed by being sandwiched vertically between the upper surface 28 of the recess and the bottom surfaces 22b of the support parts 22, and the left end of the second semiconductor element 5 is located on the left side of the recess 21. The second semiconductor element 5 is fixed to the recess 21 without the use of a bonding material. The entire second semiconductor element 5 is housed within the recess 21, and the upper surface of the second semiconductor element 5 is located below the upper surface 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 ​​the upper surface of the second semiconductor element 5 other than the upper surface 28 of the recess. Figures 15 and 16 show the state in which the wire 6b is connected to the area in front of the upper surface 28 of the recess on the upper surface of the second semiconductor element 5.

[0047] Next, the manufacturing method of the semiconductor device 400 will be described. Note that the manufacturing method in Embodiment 2 differs from that in the lead frame preparation process and the process of mounting the second semiconductor element 5, so these points will be explained in detail. As shown in Figures 18 and 19, the molded recess 19 of the first mold 17 is composed of a pair of recess components 23 arranged in the front-to-back direction and an intermediate recess component 26 provided between the pair of recess components 23. The upper surface of the recess components 23 is lower than the intermediate recess component 26. On the upper surface of each recess component 23, an inclined surface corresponding to the side surface 22a and the bottom surface 22b of the support portion 22, and a flat surface perpendicular to the vertical direction are formed. The molded protrusion 20 of the second mold 18 is composed of a pair of protrusion components 24 arranged in the front-to-back direction. The protrusion components 24 are provided at positions corresponding to the recess components 23 of the first mold 17. The lower surface of the protruding component 24 has inclined surfaces and a flat surface perpendicular to the vertical direction, which correspond to the side surface 22a and bottom surface 22b of the support portion 22, respectively. Cut portions 24a are provided at both the front and rear ends of the lower surface of the protruding component 24, which protrude downward from the rest of the lower surface. In the punching process in the lead frame preparation process (step S1) described above, the molded protrusion 20 advances downward from the three parts of the molded recess 19, causing the protruding component 24 to bend the original plate 15 to form the support portion 22, and the portion between the two support portions 22 of the original plate 15 is left unprocessed to form the upper recess portion 28. In the semiconductor element mounting process (step S2) described above, the second semiconductor element 5 is inserted from the left side of the recess 21 between the upper recess portion 28 and the bottom surface 22b of the support portion 22, and the second semiconductor element 5 is fixed by being sandwiched from above and below by the upper recess portion 28 and the bottom surface portion 22b.

[0048] As described above, the second semiconductor element 5 is fixed in the recess 21 without the need for a bonding material by being sandwiched from above and below by the bottom surface 22b of the support portion 22 and the upper surface 28 of the recess. This eliminates the need for a bonding material, and consequently, the heating process required for curing the bonding material is also eliminated. Therefore, the manufacturing man-hours for the semiconductor device 400 can be reduced.

[0049] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0050] Figure 20 shows a modified example of Embodiment 1. The second semiconductor element 5 may be fixed in the recess 14 in a state where it protrudes to the left of the left end of the recess 14 while maintaining an insulating distance from the first semiconductor element 4. This allows for a further reduction in the length of the wire 6b. In Embodiments 2 to 4, the second semiconductor element 5 may also be fixed in the recess 21 in a state where it protrudes to the left of the left end of the recess 21. Furthermore, when the second semiconductor element 5 is fixed in a protruding state as described above, it is preferable that the side portion 14b of the recess 14 or the side portion 22a of the support portion 22 is inclined from the viewpoint of bonding strength with the second semiconductor element 5. Figure 20 shows a configuration in which the side portion 14b of the recess 14 is inclined. In addition, the recess 14 may be provided with a side portion that rises upward around its entire circumference.

[0051] Embodiments 2 to 4 show examples in which two support parts 22 are provided, but the invention is not limited to this, and three or more may be provided.

[0052] In the above embodiment, the first frame portion 9 and the second frame portion 10 are provided on a single lead frame 7, but the first frame portion 9 and the second frame portion 10 may be provided 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 member.

[0053] The various aspects of this disclosure are summarized below as an appendix.

[0054] (Note 1) First semiconductor device, A second semiconductor element connected to the first semiconductor element, A wire connecting the first semiconductor element and the second semiconductor element, The first frame portion on which the first semiconductor element is provided, A second frame portion is positioned above and separated from the first frame portion in the left-right direction, and the second semiconductor element is provided on the second frame portion, The device comprises the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and a sealing member for sealing the wire, The upper surface of the second frame portion is provided with a recess that is recessed downwards. The recess is located above the first frame portion, The second semiconductor element is fixed in the recess. Semiconductor equipment. (Note 2) The recess is provided on the edge of the upper surface of the second frame portion on the side of the first frame portion, and is open toward the first frame portion. The semiconductor device described in Appendix 1. (Note 3) The second semiconductor element is fixed in the recess with its end located at the open end of the recess, or with its end protruding further toward the first frame portion than the open end of the recess. Semiconductor device as described in Appendix 2. (Note 4) The recess is provided with a bottom surface and a side surface that slopes upward as it moves away from the bottom surface. The second semiconductor element is fixed to the bottom and side surfaces via a bonding material. A semiconductor device as described in any of the appendices 1 to 3. (Note 5) The recess is provided with a plurality of support portions that are spaced apart from each other in the front-to-back direction intersecting the left-to-right direction and support the second semiconductor element. Each of the support portions has a bottom portion and a side portion that extends upward from the bottom portion and connects to the peripheral edge of the recess in the second frame portion. The second semiconductor element is fixed to a plurality of the support parts. A semiconductor device as described in any of the appendices 2 to 4. (Note 6) The recess has a positioning portion provided in the left-right direction at a position opposite to the open end of the recess, The second semiconductor element is in contact with the positioning portion, Semiconductor device as described in Appendix 5. (Note 7) The recess is provided with an upper surface portion located above the bottom surface portion. The second semiconductor element is fixed by being sandwiched between the bottom portion and the top portion. Semiconductor device as described in Appendix 5. (Note 8) A preparation step of preparing a first frame portion and a second frame portion provided above the first frame portion and separated from it in the left-right direction, A mounting step comprising 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 with a wire, A sealing step 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, Equipped with, In the aforementioned preparation step, A first mold having a molding recess, a second mold positioned opposite the molding recess and moving back and forth relative to the first mold, having a molding protrusion corresponding to the molding recess, and a base plate for the second frame are prepared. The base plate is placed in the region including the molded recess in the first mold, The second mold advances toward the first mold and punches out the original plate to form the second frame portion, and a recess is formed in the formed second frame portion that is recessed downward and located above the first frame portion. In the aforementioned mounting process, The second semiconductor element is fixed in the recess. A method for manufacturing a semiconductor device. [Explanation of symbols]

[0055] 1,200,300,400 Semiconductor device, 2 Encapsulating member, 4 First semiconductor element, 5 Second semiconductor element, 6b Wire, 9 First frame section, 10 Second frame section, 10a Top surface of the second frame section, 14,21 Recess, 14a Bottom surface of the recess, 14b Side surface of the recess, 15 Original plate, 16 Molding die, 17 First mold, 18 Second mold, 22 Support section, 22a Side surface, 22b Bottom surface, 25 Positioning section, 25a Side surface, 25b Bottom surface, 28 Top surface of the recess

Claims

1. First semiconductor device, A second semiconductor element connected to the first semiconductor element, A wire connecting the first semiconductor element and the second semiconductor element, The first frame portion on which the first semiconductor element is provided, A second frame portion is positioned above and separated from the first frame portion in the left-right direction, and the second semiconductor element is provided on the second frame portion, The device comprises the first semiconductor element, the second semiconductor element, the first frame portion, the second frame portion, and a sealing member for sealing the wire, The upper surface of the second frame portion is provided with a recess that is recessed downwards. The recess is located above the first frame portion, The second semiconductor element is fixed in the recess. Semiconductor equipment.

2. The recess is provided on the edge of the upper surface of the second frame portion on the side of the first frame portion, and is open toward the first frame portion. The semiconductor device according to claim 1.

3. The second semiconductor element is fixed in the recess with its end located at the open end of the recess, or with its end protruding further toward the first frame portion than the open end of the recess. The semiconductor device according to claim 2.

4. The recess is provided with a bottom surface and a side surface that slopes upward as it moves away from the bottom surface. The second semiconductor element is fixed to the bottom and side surfaces via a bonding material. The semiconductor device according to any one of claims 1 to 3.

5. The recess is provided with a plurality of support portions that are spaced apart from each other in the front-to-back direction intersecting the left-to-right direction and support the second semiconductor element. Each of the support portions has a bottom portion and a side portion that extends upward from the bottom portion and connects to the peripheral edge of the recess in the second frame portion. The second semiconductor element is fixed to a plurality of the support parts. The semiconductor device according to claim 2 or 3.

6. The recess has a positioning portion provided in the left-right direction at a position opposite to the open end of the recess, The second semiconductor element is in contact with the positioning portion, The semiconductor device according to claim 5.

7. The recess is provided with an upper surface portion located above the bottom surface portion. The second semiconductor element is fixed by being sandwiched between the bottom portion and the top portion. The semiconductor device according to claim 5.

8. A preparation step of preparing a first frame portion and a second frame portion provided above the first frame portion and separated from it in the left-right direction, A mounting step comprising 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 with a wire, A sealing step 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, Equipped with, In the aforementioned preparation step, A first mold having a molding recess, a second mold positioned opposite the molding recess and moving back and forth relative to the first mold, having a molding protrusion corresponding to the molding recess, and a base plate for the second frame are prepared. The base plate is placed in the region including the molded recess in the first mold, The second mold advances toward the first mold and punches out the original plate to form the second frame portion, and a recess is formed in the formed second frame portion that is recessed downward and located above the first frame portion. In the aforementioned mounting process, The second semiconductor element is fixed in the recess. A method for manufacturing a semiconductor device.

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