Semiconductor module and method for manufacturing same

Abstract

A purpose of the present invention is to prevent a molding failure from occurring due to a sealing resin protruding outside of a case during transfer molding.　A semiconductor module (1) has a case (11) and an encapsulating resin (40). The case (11) includes, on the upper surface thereof, a first region and a second region that is thinner than the first region. The second region is formed with a first opening (11a1) and a recess (11d1) that surrounds the first opening (11a1) in an annular shape. The encapsulating resin (40) is filled in the case (11).

Description

Semiconductor module and manufacturing method thereof

[0001] The present invention relates to a semiconductor module and a method for manufacturing the same.

[0002] There are semiconductor devices in which holes are provided on the top surface of the case for injecting sealing resin or introducing high-pressure gas (see, for example, Patent Documents 1 to 3). There are also electronic control devices in which a ventilation hole is provided on the top surface of a cover that covers a circuit board to eliminate the pressure difference between the inside and outside (see, for example, Patent Document 4). There is also technology in which protrusions are provided on the mold at positions corresponding to the holes in the lead frame to reduce the gap when the lead frame is clamped between upper and lower molds (see, for example, Patent Document 5).

[0003] Japanese Patent Laid-Open No. 6-188335 Japanese Patent Laid-Open No. 2003-273260 Japanese Patent Laid-Open No. 2005-294792 Japanese Patent Laid-Open No. 2012-69647 Japanese Patent Laid-Open No. 6-304959

[0004] The object of this embodiment is to prevent molding defects from occurring when the sealing resin protrudes outside the case during transfer molding.

[0005] According to one aspect of the present invention, there is provided a semiconductor module having a case including, on its upper surface, a first region and a second region that is thinner than the first region and has a first opening and a recessed portion that surrounds the first opening in a ring shape, and a sealing resin filled in the case.

[0006] The case may have an upper end portion that is flush with an upper surface of the first region, at a position closer to the first opening than the recessed portion in a plan view.

[0007] The case may have, in the second region, an annular rising region that rises from the recessed portion toward the central axis direction of the first opening.

[0008] The case may have an annular first portion that is included on the central axis side of the rising region, surrounds the first opening, and is inclined downward from the central axis of the first opening.

[0009] The second region may include a connection region that connects to the first region, and the upper surface of the connection region may descend from the same height as the upper surface of the first region toward the central axis of the first opening to a height lower than the upper surface of the first region, and the thickness of the connection region may decrease toward the central axis.

[0010] The case may have a groove on the top surface at a position farther from the first opening than the recessed portion.

[0011] The sealing resin may be filled up to an upper surface of an inner wall of the case, and a sealing surface at the first opening may be flush with an upper surface of an outer wall of the case.

[0012] The semiconductor device may have a semiconductor element and a conductive pattern layer on which the semiconductor element is arranged, at least a portion of the upper surface of which is covered by the case, and the semiconductor element may be provided in an area other than directly below the first opening.

[0013] The semiconductor device may include a semiconductor element, a plurality of conductive pattern layers, and a connection member that electrically connects any of the plurality of conductive pattern layers to the semiconductor element or electrically connects the plurality of conductive pattern layers to each other, and the connection member may be provided in an area other than directly below the first opening, or the connection member may have a second opening at the same position as the first opening in a planar view.

[0014] The case may have a terminal having one end protruding from the inner surface of the case to the inside of the case and the other end exposed to the outside of the case.

[0015] A part of the connection member may be a printed circuit board.

[0016] The semiconductor device may include an insulating circuit board having a semiconductor element and an insulating circuit board to which the semiconductor element is bonded, which is placed in the case, and which is sealed together with the semiconductor element by the sealing resin within the case, and the insulating circuit board may include an insulating layer and a conductive pattern layer to which the semiconductor element is bonded.

[0017] The conductive pattern layer of the insulating circuit board may have a third opening at the same position as the first opening in a plan view.

[0018] The third opening may not penetrate through the conductive pattern layer.

[0019] The sealing resin may be made of a hard resin.

[0020] According to one aspect of the present invention, there is provided a method for manufacturing a semiconductor module, comprising the steps of: preparing a case including, on its upper surface, a first region; a second region having a thickness thinner than the first region, a first opening, and a rising region surrounding the first opening and rising upward relative to the upper surface of the first region on the central axis side of the first opening; and a component having the second opening; and pressing the upper surface of the case, in which the first opening and the second opening are positioned and the component is housed, with a main surface of a mold facing the upper surface of the case, and filling the case with sealing resin while the rising region is pressed downward.

[0021] The sealing resin may be filled in a state where the upper end of the rising region is brought into contact with a main surface of the mold by pressing with the mold.

[0022] In the preparation step, the case has a ring-shaped first part that is included on the central axis side of the rising region, surrounds the first opening, and is parallel to the top surface of the case, and in the sealing resin filling step, the mold may press the first part, thereby pushing the rising region together with the first part downward from the top surface of the case.

[0023] The second region may include a connection region that connects to the first region, and the upper surface of the connection region may descend from the same height as the upper surface of the first region toward the central axis to a height lower than the upper surface of the first region, and the thickness of the connection region may decrease toward the central axis.

[0024] The case may have, in the second region, a ring-shaped recessed portion surrounding the first opening at a position farther from the first opening than the rising region, and a groove provided at a position farther from the first opening than the recessed portion.

[0025] The positioning may be performed by inserting a common positioning member into the first opening and the second opening.

[0026] The sealing resin may be made of a hard resin.

[0027] According to one aspect of the present invention, there is provided a semiconductor module having: a case including a first opening on an upper surface; a printed circuit board disposed within the case and including a second opening formed in the same position as the first opening in a planar view; and an insulating circuit board disposed within the case below the printed circuit board and including an insulating layer and a conductive pattern layer to which a semiconductor element is bonded, and including a third opening formed in the conductive pattern layer in the same position as the first opening and the second opening in a planar view.

[0028] According to one aspect of the present invention, there is provided a method for manufacturing a semiconductor module, comprising the steps of: preparing a case including a first opening on its top surface, a printed circuit board including a second opening, and an insulating circuit board including a conductive pattern layer to which an insulating layer and a semiconductor element are bonded, and a third opening formed in the conductive pattern layer; inserting a common positioning member into the first opening, the second opening, and the third opening to position the case, the printed circuit board housed in the case, and the insulating circuit board placed below the printed circuit board, thereby joining them; and removing the positioning member, filling the case with sealing resin to seal the printed circuit board and the insulating circuit board.

[0029] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions.

[0030] The disclosed technology can prevent molding defects caused by the encapsulating resin spilling out of the case during transfer molding. The above and other objects, features, and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, which illustrate preferred embodiments of the present invention by way of example.

[0031] 6 is a plan view showing the appearance of a semiconductor module of a comparative example. FIG. 7 is a cross-sectional view of the semiconductor module of the comparative example taken along line II-II in FIG. 1 . FIG. 8 is a plan view of a printed circuit board and an insulating circuit board. FIG. 9 is a diagram showing positioning using a positioning member. FIG. 10 is a diagram showing a problem that occurs during manufacturing of the semiconductor module of the comparative example. FIG. 11 is a plan view of the semiconductor module of the first embodiment before clamping. FIG. 12 is a cross-sectional view of the semiconductor module of the first embodiment before clamping. FIG. 13 is a diagram showing the state of the semiconductor module of the first embodiment during clamping. FIG. 14 is a diagram showing the state of filling sealing resin into the case of the semiconductor module of the first embodiment. FIG. 15 is a cross-sectional view of the semiconductor module of the first embodiment after clamping. FIG. 16 is a plan view and a cross-sectional view of the periphery of a first opening in the case of the semiconductor module of the first embodiment after clamping. FIG. 17 is a plan view and a cross-sectional view of the periphery of the first opening in the case of the semiconductor module of the second embodiment before clamping. FIG. 18 is a plan view and a cross-sectional view of the periphery of the first opening in the case of the semiconductor module of the second embodiment after clamping. 10A and 10B are a plan view and a cross-sectional view of the periphery of a first opening in a case of a semiconductor module according to a third embodiment after mold clamping; a plan view and a cross-sectional view of the periphery of a first opening in a case of a semiconductor module according to a fourth embodiment before mold clamping; a plan view and a cross-sectional view of the periphery of a first opening in a case of a semiconductor module according to a fourth embodiment after mold clamping; a diagram showing a manufacturing process of a semiconductor module; a cross-sectional view showing positioning using a positioning member; and a diagram showing a modified example of a semiconductor module.

[0032] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the terms "front surface" and "top surface" refer to the X-Y plane facing upward (+Z direction) in the semiconductor module 1a of FIG. 2 and the like. Similarly, "up" refers to the upward (+Z direction) direction in the semiconductor module 1a of FIG. 2 and the like. The terms "back surface" and "bottom surface" refer to the X-Y plane facing downward (-Z direction) in the semiconductor module 1a of FIG. 2 and the like. Similarly, "bottom" refers to the downward (-Z direction) direction in the semiconductor module 1a of FIG. 2 and the like. Similar directions will be used in other drawings as necessary. The terms "front surface," "top surface," "top," "back surface," "bottom surface," and "bottom" are merely convenient expressions for specifying relative positional relationships and do not limit the technical concept of the present invention. For example, "up" and "bottom" do not necessarily refer to the vertical direction relative to the ground. In other words, the "up" and "down" directions are not limited to the direction of gravity.

[0033] First, before describing the semiconductor module of the first embodiment, a semiconductor module of a comparative example will be described below. (Comparative Example) Fig. 1 is a plan view showing the appearance of the semiconductor module of the comparative example. Fig. 2 is a cross-sectional view of the semiconductor module of the comparative example taken along line II-II in Fig. 1. Fig. 3 is a plan view of a printed circuit board and an insulating circuit board. The semiconductor module 1a of the comparative example has a case 11, semiconductor elements 13a to 13h, an insulating circuit board 20, a printed circuit board 30, and a sealing resin 40.

[0034] Case 11 has first openings 11a1 and 11a2, which are through-holes, on its top surface. Positioning members are inserted into first openings 11a1 and 11a2 when positioning case 11 relative to components (insulated circuit board 20 and printed circuit board 30) to be installed inside case 11. Because a pin-shaped positioning member is inserted into first opening 11a1, first opening 11a1 is located at the same position in plan view as second opening 30d1 of printed circuit board 30 and third opening 20d1 of insulating circuit board 20. Similarly, first opening 11a2 is located at the same position in plan view as second opening 30d2 of printed circuit board 30 and third opening 20d2 of insulating circuit board 20.

[0035] The diameter of the first openings 11a1 and 11a2 is determined according to the diameter of the positioning member used. If the positioning member is too thin, it may be prone to deformation. If the positioning member is too thick, the opening sizes of the second openings 30d1 and 30d2 provided in the printed circuit board 30 and the third openings 20d1 and 20d2 provided in the insulating circuit board 20 must also be large. For this reason, it is preferable that the diameter of the positioning member is, for example, 1 mm or more and 2 mm or less, and that the diameter of the first openings 11a1 and 11a2 is also 1 mm or more and 2 mm or less accordingly.

[0036] The shape of the first openings 11a1 and 11a2 in a plan view is not limited to the circular shape shown in FIG. 1. The shape of the first openings 11a1 and 11a2 in a plan view may be a shape other than a circle, such as a square. The number of first openings is also not limited to two. However, for accurate positioning, it is preferable to have at least two first openings.

[0037] Furthermore, the case 11 has terminals 12a to 12c, one end of which protrudes from the inner surface of the case into the inside of the case and the other end of which is exposed to the outside of the case 11. The terminals 12a to 12c are integrally molded with the case 11.

[0038] Case 11 is formed by injection molding using a thermoplastic resin, for example. The thermoplastic resin may be, for example, polyphenylene sulfide resin, polybutylene terephthalate resin, polybutylene succinate resin, polyamide resin, acrylonitrile butadiene styrene resin, or a liquid crystal polymer. Case 11 has a thickness required for molding. Such a thickness is, for example, 1 mm or more and 2 mm or less.

[0039] Terminals 12a and 12b are external connection terminals for main current to which different potentials are applied. For example, terminal 12a is connected to the negative terminal of a DC power supply, and terminal 12b is connected to the positive terminal of the DC power supply. Terminal 12c is an output terminal. Terminals 12a to 12c are made of a material with excellent conductivity. Examples of such materials include aluminum, iron, silver, copper, or an alloy containing at least one of these. The number of terminals can be varied as appropriate depending on the type of semiconductor module 1a. If semiconductor module 1a is a three-level inverter, a terminal called a neutral terminal (or intermediate terminal) may be integrally molded with case 11. Although not shown, other terminals, such as control terminals electrically connected to the control electrodes of semiconductor elements 13a to 13h, may also be integrally molded with case 11. The spaces between the terminals are filled with resin from case 11, maintaining insulation between the terminals.

[0040] Note that, in an area of ​​the top surface of case 11 where first openings 11a1 and 11a2 are not provided, one or more openings (through holes) having a larger opening area than first openings 11a1 and 11a2 may be provided so that internal components can be seen during assembly. Also, in order to reduce the weight of case 11 and the amount of raw materials used to construct case 11, a recessed opening that does not penetrate the top surface may be provided in the top surface of case 11.

[0041] 3B, the semiconductor elements 13a to 13h are mounted on the main surface of the insulating circuit board 20. The main surface of the insulating circuit board 20 is the front surface (top surface) of the conductive pattern layers 20a1 to 20a3. At least a portion of the top surfaces of the semiconductor elements 13a to 13h and the conductive pattern layers 20a1 to 20a3 are covered by the case 11.

[0042] The semiconductor elements 13a, 13b, 13e, and 13f are joined to the front surface of the conductive pattern layer 20a1 by a joining member (e.g., joining member 15b in FIG. 2) such as solder or a sintered material (copper or silver). The semiconductor elements 13c, 13d, 13g, and 13h are joined to the front surface of the conductive pattern layer 20a2 by a joining member (e.g., solder or a sintered material).

[0043] The semiconductor elements 13a to 13h may be power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) primarily made of silicon carbide. The body diode of the power MOSFET may function as an FWD (Free Wheeling Diode). The semiconductor elements 13a to 13h may include a switching element primarily made of silicon. The switching element may be, for example, an RC (Reverse-Conducting)-IGBT. An RC-IBGT combines the functions of an IGBT and an FWD. Furthermore, the semiconductor elements 13a to 13h may be semiconductor chips each including a pair of switching element and diode element primarily made of silicon. The switching element may be, for example, a power MOSFET or an IGBT. The diode element may be, for example, an SBD (Schottky Barrier Diode) or a PiN (P-intrinsic-N) diode, which serves as the FWD.

[0044] Although not shown, main electrodes and control electrodes are provided on the front surfaces of the semiconductor elements 13a to 13h. If the semiconductor elements 13a to 13h are IGBTs, the main electrodes are emitter electrodes. If the semiconductor elements 13a to 13h are power MOSFETs, the main electrodes are source electrodes. The main electrodes on the front surfaces are joined to the printed circuit board 30 by a joining member such as solder or a sintered material (e.g., joining member 15c in FIG. 2 ) and electrically connected to one of the terminals 12a to 12c via the printed circuit board 30. The control electrodes are gate electrodes of the switching elements included in the semiconductor elements 13a to 13h. The control electrodes are joined to the printed circuit board 30 by a joining member such as solder or a sintered material and electrically connected to a control terminal (not shown) via the printed circuit board 30. The main electrodes and control electrodes on the front surfaces of the semiconductor elements 13a to 13h may also be joined to the printed circuit board 30 via pin-shaped connecting members joined by a joining member.

[0045] Although not shown, the semiconductor elements 13a to 13h also have main electrodes on their rear surfaces. If the semiconductor elements 13a to 13h are IGBTs, the main electrode on the rear surface is a collector electrode. If the semiconductor elements 13a to 13h are power MOSFETs, the main electrode on the rear surface is a drain electrode. The main electrode on the rear surface of the semiconductor elements 13a to 13h is electrically connected to one of the terminals 12a to 12c via conductive pattern layers 20a1 to 20a3, pin-shaped connecting members (e.g., connecting members 14a and 14b in FIGS. 2 and 3B), or printed circuit board 30.

[0046] The number of semiconductor elements is not limited to the above. The number of semiconductor elements provided depends on the specifications of the semiconductor module 1a. In addition, other semiconductor elements such as diode elements may be mounted on the insulating circuit board 20.

[0047] 2 and 3B, the insulating circuit board 20 has a rectangular shape in a plan view. The insulating circuit board 20 includes conductive pattern layers 20a1-20a3, a metal layer 20b, and an insulating layer 20c sandwiched between the conductive pattern layers 20a1-20a3 and the metal layer 20b, at least a portion of which is covered by the case 11.

[0048] The outer peripheral edge of the insulating layer 20c of the conductive pattern layers 20a1 to 20a3 preferably overlaps the outer peripheral edge of the insulating layer 20c of the metal layer 20b in plan view, so that the insulating circuit board 20 maintains a stress balance with the metal layer 20b on the back surface of the insulating layer 20c, and damage to the insulating layer 20c such as excessive warping and cracking is suppressed.

[0049] The conductive pattern layers 20a1 to 20a3 are made of a metal with excellent conductivity, such as copper, aluminum, or an alloy containing at least one of these metals.

[0050] The terminal 12c is bonded to the conductive pattern layer 20a1, the terminal 12b is bonded to the conductive pattern layer 20a2, and the terminal 12a is bonded to the conductive pattern layer 20a3 by a bonding member such as solder or a sintered material (for example, a bonding member 15a as shown in FIG. 2). Note that instead of using such bonding members, bonding can also be performed by ultrasonic bonding.

[0051] The metal layer 20b has a rectangular shape in a plan view. The corners may be rounded or chamfered. The metal layer 20b is smaller than the insulating layer 20c and is formed on the entire surface of the insulating layer 20c except for the edges. The metal layer 20b is mainly composed of a metal with excellent thermal conductivity. The metal is, for example, copper, aluminum, or an alloy containing at least one of these.

[0052] The insulating layer 20c has a rectangular shape in a plan view. The corners of the insulating layer 20c may be rounded or chamfered. The insulating layer 20c is made of an insulating resin. The insulating resin may be a material with low thermal resistance and high insulation properties. Examples of such resins include thermosetting resins. Examples of thermosetting resins include at least one of epoxy resin, cyanate resin, polyimide resin, benzoxazine resin, unsaturated polyester resin, phenol resin, melamine resin, silicone resin, and maleimide resin. The thermosetting resin may further contain a filler. The filler is made of at least one of an oxide and a nitride. Examples of oxides include silicon oxide and aluminum oxide. Examples of nitrides include silicon nitride, aluminum nitride, and boron nitride. Furthermore, the filler may be hexagonal boron nitride.

[0053] An insulating plate containing ceramic as its main component may be used as the insulating layer 20c of the insulating circuit board 20. Such ceramics may be composed of a material containing aluminum oxide, aluminum nitride, or silicon nitride as its main component, for example. In this case, the insulating circuit board 20 may be, for example, a DCB (Direct Copper Bonding) board or an AMB (Active Metal Brazed) board.

[0054] Furthermore, the conductive pattern layers 20a1 and 20a2 of the insulating circuit board 20 have third openings 20d1 and 20d2 at the same positions as the first openings 11a1 and 11a2 in a plan view. As shown in FIG. 2, the third opening 20d1 does not penetrate the conductive pattern layer 20a2. However, the third opening 20d1 may penetrate the conductive pattern layer 20a2 and reach the insulating layer 20c. The same applies to the third opening 20d2. The diameters of the third openings 20d1 and 20d2 correspond to the diameter of the positioning member (for example, approximately 1 to 2 mm).

[0055] The shape of the third openings 20d1 and 20d2 in a plan view is not limited to the circular shape shown in Fig. 3B. The shape of the third openings 20d1 and 20d2 in a plan view may be a shape other than a circle, such as a square. The number of third openings 20d1 and 20d2 is also not limited to two.

[0056] Because such third openings 20d1 and 20d2 are formed, the semiconductor elements 13a to 13h, at least a portion of whose upper surfaces are covered by the case 11, are provided in an area other than directly below the first openings 11a1 and 11a2.

[0057] Furthermore, a connecting member (such as connecting members 14a and 14b in FIGS. 2 and 3B) extending in the +Z direction and electrically connecting the insulating circuit board 20 and the printed circuit board 30 may be provided on the main surface of the insulating circuit board 20. For example, as shown in FIG. 2, one end of connecting member 14a is bonded to one end of the conductive pattern layer 20a1, and the other end of connecting member 14a is bonded to the conductive pattern layer 30a2 of the printed circuit board 30. Such connecting members are provided in regions other than those directly below the first openings 11a1 and 11a2. The connecting member electrically connects one of the conductive pattern layers 20a1 to 20a3 to the semiconductor elements 13a to 13h, or electrically connects the conductive pattern layers 20a1 to 20a3 to each other. Wire bonds may also be used as the connecting members.

[0058] The printed circuit board 30 is also a part of the connecting member. The printed circuit board 30 is provided inside the case 11, facing the main surface of the insulating circuit board 20. The printed circuit board 30 has conductive pattern layers 30a1 to 30a3 provided on the back surface, a conductive pattern layer 30b provided on the front surface, and an insulating layer 30c provided between the conductive pattern layers 30a1 to 30a3 and the conductive pattern layer 30b.

[0059] The conductive pattern layers 30a1 to 30a3 are electrically connected to the semiconductor elements 13a to 13h or the conductive pattern layers 20a1 and 20a3 of the insulating circuit board 20. The conductive pattern layer 30b is electrically connected to one of the conductive pattern layers 30a1 to 30a3, for example, via a via hole provided in the insulating layer 30c. The conductive pattern layer 30b is electrically connected to an external connection terminal such as a control terminal, although not shown.

[0060] The conductive pattern layers 30a1 to 30a3 and 30b are made of a metal with excellent conductivity, such as copper, aluminum, or an alloy containing at least one of these as a main component.

[0061] The insulating layer 30c is formed of, for example, an insulating resin. Examples of insulating layers that can be used include a paper phenol substrate, a paper epoxy substrate, a glass composite substrate, and a glass epoxy substrate.

[0062] The printed circuit board 30 may have a multi-layer structure in which one or more conductive pattern layers are formed inside the insulating layer 30c.

[0063] The printed circuit board 30 has second openings 30d1 and 30d2 at the same positions as the first openings 11a1 and 11a2 in a plan view. As shown in FIG. 2, the second opening 30d1 is a through hole. The same is true for the second opening 30d2. The diameters of the second openings 30d1 and 30d2 correspond to the diameter of the positioning member (for example, approximately 1 to 2 mm).

[0064] The shape of the second openings 30d1 and 30d2 in plan view is not limited to the circular shape shown in Fig. 3A. The shape of the second openings 30d1 and 30d2 in plan view may be a shape other than a circle, such as a square. The number of second openings 30d1 and 30d2 is also not limited to two.

[0065] The sealing resin 40 fills the case 11 and seals the semiconductor elements 13a-13h, the insulating circuit board 20, and the printed circuit board 30. The sealing resin 40 also fills the first openings 11a1 and 11a2, the second openings 30d1 and 30d2, and the third openings 20d1 and 20d2. When sealing is performed by transfer molding, the sealing resin 40 is made of a hard resin rather than a soft resin such as a gel. For example, a thermosetting resin such as an epoxy resin is used as the hard resin.

[0066] When manufacturing such a semiconductor module 1a, the case 11, the semiconductor elements 13a to 13h, the insulating circuit board 20, and the printed circuit board 30 are positioned relative to one another using positioning members in the joining process.

[0067] 4 is a diagram showing the state of positioning using positioning members. First, insulating circuit board 20 is mounted on a joining jig (not shown), and joining members such as solder (joining members 15a, 15b, etc.) are placed on insulating circuit board 20. Then, semiconductor elements 13a-13h and pin-shaped connecting members (connecting member 14a, etc.) are placed on the joining members. Then, joining members (joining member 15c, etc.) are placed on top of those.

[0068] Then, a pin-shaped positioning member 50 is set in the third opening 20d1. As shown in Fig. 4, for example, the positioning member 50 is fixed in a state in which the tip of the positioning member 50 is inserted into the third opening 20d1 of the insulating circuit board 20. Although not shown in Fig. 4, a pin-shaped positioning member is similarly set in the third opening 20d2 shown in Fig. 3(B).

[0069] Thereafter, the printed circuit board 30 is set on the insulating circuit board 20 so that the positioning member 50 is inserted into the second opening 30d1. Although not shown in FIG. 4, a pin-shaped positioning member is similarly inserted into the second opening 30d2 shown in FIG. 3A. The case 11 is also set so that the positioning member 50 is inserted into the first opening 11a1. Although not shown in FIG. 4, a pin-shaped positioning member is similarly inserted into the first opening 11a2 shown in FIG. 1. This results in the state shown in FIG. 4. In this state, the various parts are joined using joining members.

[0070] As described above, case 11 has first openings 11a1 and 11a2, and insulating circuit board 20 has third openings 20d1 and 20d2, so that terminals 12a to 12c of case 11 can be joined to appropriate positions on insulating circuit board 20. Furthermore, as case 11 has first openings 11a1 and 11a2, and printed circuit board 30 has second openings 30d1 and 30d2, the insulating circuit board 20 and printed circuit board 30 can be fixed in an appropriate positional relationship. This allows printed circuit board 30 to be joined to appropriate positions relative to semiconductor elements 13a to 13h and connecting members arranged on insulating circuit board 20.

[0071] After the bonding process described above, the positioning member 50 is removed, and the sealing process is performed by transfer molding. At this time, the following problems may occur. Figure 5 illustrates a problem that occurs during the manufacture of a semiconductor module of a comparative example. Figure 5A illustrates an example in which a semiconductor module 1a of the comparative example, which has not yet been filled with sealing resin 40, is clamped between an upper mold 60a and a lower mold 60b. Figure 5B illustrates how the sealing resin 40 is being filled into the case 11. The arrows in Figure 5B indicate an example of the direction in which the sealing resin 40 spreads. Note that in Figures 5A and 5B, the components within the case 11 (such as semiconductor elements 13a to 13h, the insulating circuit board 20, and the printed circuit board 30) are not shown.

[0072] In the semiconductor module 1a of the comparative example, as described above, the first opening 11a1 into which the positioning member 50 is inserted is provided on the top surface of the case 11. In order to prevent the sealing resin 40 from leaking from the first opening 11a1 during the sealing process, it is desirable to apply pressure using the upper mold 60a so that the gap between the top surface of the case 11 and the upper mold 60a is as small as possible, thereby reducing the gap.

[0073] However, due to variations in component dimensions in the Z direction or warping or undulation of the top surface of the case 11, the periphery of the first opening 11a1 on the top surface of the case 11 may sink toward the lower mold 60b, as shown in FIG. 5A . In this case, a gap may be formed between the periphery of the first opening 11a1 on the top surface of the case 11 and the upper mold 60a. In this case, as shown in FIG. 5B , the sealing resin 40 may leak from inside the case 11 into the gap through the first opening 11a1. If the sealing resin 40 leaks out in this way, resin burrs will form around the first opening 11a1 on the top surface of the case 11 after the sealing resin 40 hardens, leading to molding defects.

[0074] The semiconductor module of the first embodiment described below is designed to prevent molding defects caused by the sealing resin spilling out of the case during transfer molding. The semiconductor module of the first embodiment also reduces the cost of measures to prevent leakage of the sealing resin.

[0075] (First embodiment) Fig. 6 is a plan view of a semiconductor module according to a first embodiment before clamping. Fig. 7 is a cross-sectional view of the semiconductor module according to the first embodiment before clamping, taken along line VII-VII in Fig. 6. In Figs. 6 and 7, the same elements as those shown in Figs. 1 and 2 are designated by the same reference numerals.

[0076] The case 11 of the semiconductor module 1 of the first embodiment has, on its top surface, a first region 11c and second regions 11c1 and 11c2 that are thinner than the first region 11c. The thickness of the first region 11c is at least the thickness required for molding this region, and is, for example, 1 mm or more and 2 mm or less. In contrast, the thickness of the second regions 11c1 and 11c2 may be, for example, 0.2 mm or more and 0.3 mm or less, since the second regions 11c1 and 11c2 are narrower. The second regions 11c1 and 11c2, which are thinner than the first region 11c, are part of the top surface of the case 11, and therefore the strength of the case 11 can be maintained.

[0077] In addition, on the top surface of the case 11, regions thinner than the first region 11c may be provided in addition to the second regions 11c1 and 11c2.

[0078] Furthermore, the case 11 has first openings 11a1 and 11a2 in the second regions 11c1 and 11c2, through which positioning members are inserted. As described above, the diameters of the first openings 11a1 and 11a2 are determined according to the diameter of the positioning members used, and are preferably, for example, 1 mm or more and 2 mm or less. The planar shapes of the first openings 11a1 and 11a2 are not limited to the circular shapes shown in FIG. 6 . The planar shapes of the first openings 11a1 and 11a2 may be other shapes, such as rectangular. The number of first openings is not limited to two. However, for accurate positioning, it is preferable to have at least two first openings.

[0079] Furthermore, the second region 11c1 is formed with a rising region 11b1 that surrounds the first opening 11a1 and whose central axis side of the first opening 11a1 rises upward relative to the upper surface of the first region 11c, as shown in Fig. 7. The Z-direction position of the upper end 11e of the rising region 11b1 is preferably determined based on the size of a gap that may occur between the upper surface of the first region 11c and the upper mold 60a due to warping of the case 11 or the like. For example, the rising region 11b1 is formed so that the Z-direction position of the upper end 11e is 0.3 mm or more and 0.5 mm or less from the upper surface of the first region 11c in the +Z direction.

[0080] Similarly, in the second region 11c2, a rising region 11b2 is formed which surrounds the first opening 11a2 and whose central axis side of the first opening 11a2 rises upward relative to the upper surface of the first region 11c.

[0081] The semiconductor module 1 of the first embodiment has the case 11 having the above-described structure before clamping, which provides the following advantages. FIG. 8 is a diagram illustrating the state of the semiconductor module of the first embodiment when clamped. FIG. 8A illustrates the state of the case 11 before the semiconductor module 1 of the first embodiment, which is not filled with the sealing resin 40, is clamped between the upper mold 60a and the lower mold 60b. FIG. 8B illustrates the state of the case 11 after the semiconductor module 1 of the first embodiment, which is not filled with the sealing resin 40, is clamped between the upper mold 60a and the lower mold 60b. Note that in FIGS. 8A and 8B, the components inside the case 11 (such as the semiconductor elements 13a to 13h, the insulating circuit board 20, and the printed circuit board 30) are omitted from illustration.

[0082] The top surface of the case 11 is pressed in the direction of the arrow (-Z direction) as shown in FIG. 8A by the main surface of the upper mold 60a facing the top surface of the case 11. The second region 11c1 is thinner than the first region 11c and therefore less rigid than the first region 11c. Therefore, as shown in FIG. 8B, the rising region 11b1 is pressed downward (-Z direction) using the vicinity of the boundary between the second region 11c1 and the first region 11c as a fulcrum. At this time, the second region 11c1, which has been pressed downward (-Z direction) using the vicinity of this boundary as a fulcrum, has an elastic force that causes the rising region 11b1 to push back the main surface of the upper mold 60a upward (+Z direction). As a result, the pressing force from the upper mold 60a brings the upper end 11e of the rising region 11b1 into contact with the main surface of the upper mold 60a. Although not shown, the rising region 11b2 is pressed downward (in the -Z direction), and the upper end of the rising region 11b2 comes into contact with the main surface of the upper mold 60a. In addition, the pressing force of the upper mold 60a forms a recessed portion (see FIGS. 10 and 11 described below) in the second region 11c1 that surrounds the first opening 11a1 in an annular shape.

[0083] In the manufacturing method of the semiconductor module 1 according to the first embodiment, in this state, the sealing resin 40, which is a thermosetting resin such as epoxy resin, is filled into the case 11.

[0084] FIG. 9 is a diagram illustrating the filling of the encapsulating resin into the case of the semiconductor module according to the first embodiment. In the example of FIG. 9 , the injection port (also called a gate port) for the encapsulating resin 40 is provided on the short side of the case 11, but it may also be provided on the long side. Pressing by the upper mold 60a brings the upper end 11e of the rising region 11b1 into contact with the main surface of the upper mold 60a, thereby sealing the gap between the top surface of the case 11 and the main surface of the upper mold 60a. As a result, the encapsulating resin 40 filled into the case 11 is prevented from leaking out of the case 11 through the first opening 11a1 by the rising region 11b1 and the main surface of the upper mold 60a. This prevents the encapsulating resin 40 from spilling out of the case 11, resulting in molding defects.

[0085] Furthermore, since a recessed portion that annularly surrounds the first opening 11a1 is formed in the second region 11c1 by pressing the first opening 11a1 with the upper mold 60a, the sealing resin 40 flows into the recessed portion even if the sealing resin 40 leaks over the upper end portion 11e and out of the case 11. This prevents the sealing resin 40 from leaking and spreading outside the recessed portion in a plan view.

[0086] Fig. 10 is a cross-sectional view of the semiconductor module of the first embodiment. Fig. 11 is a plan view and a cross-sectional view of the periphery of a first opening in the case of the semiconductor module of the first embodiment after clamping. Fig. 11(A) is a plan view of the periphery of the first opening, and Fig. 11(B) is a cross-sectional view showing the cross section taken along line B-B in Fig. 11(A). Note that the sealing resin 40 is omitted from Fig. 11(B).

[0087] As shown in FIG. 10 , the sealing resin 40 is filled up to the upper surface of the inner wall of the case 11 , and the sealing surface at the first opening 11 a 1 is flush with the upper surface of the outer wall of the case 11 .

[0088] Furthermore, after molding, the case 11 has a recess 11d1 formed in the second region 11c1 on the top surface, in addition to the first opening 11a1, that surrounds the first opening 11a1 in an annular shape. The recess 11d1 is fixed by hardening of the hard sealing resin 40. This recess 11d1 is formed by pressing with the upper mold 60a. As shown in FIG. 9 , when the sealing resin 40 is filled into the case 11, the presence of this recess 11d1 prevents the sealing resin 40 from leaking and spreading outside the recess 11d1 in a plan view. Because of this function, the sealing resin 40 may be embedded in the recess 11d1. Although not shown, a recess that surrounds the first opening 11a1 in an annular shape is also formed in the second region 11c2, in addition to the first opening 11a2.

[0089] In addition, the case 11 has, in the second region 11c1, an annular rising region 11b1 that rises from the recessed portion 11d1 toward the central axis of the first opening 11a1. The second region 11c1 has an upper end portion 11e that is flush with the upper surface of the first region 11c and is located closer to the first opening 11a1 in a plan view than the recessed portion 11d1. In the semiconductor module 1 of the first embodiment, the upper end portion 11e corresponds to the upper end of the rising region 11b1.

[0090] By providing such an upper end portion 11e, when the sealing resin 40 is filled into the case 11, the upper end portion 11e comes into contact with the main surface of the upper mold 60a, thereby closing the gap between the top surface of the case 11 and the main surface of the upper mold 60a. This prevents the sealing resin 40 from leaking out of the case 11 through the first opening 11a1. This prevents the sealing resin 40 from spilling out of the case 11 and causing molding defects in the semiconductor module 1.

[0091] Furthermore, the above-described measures against leakage of the sealing resin 40 do not require the use of additional parts or tightening of the manufacturing tolerances of the parts, which helps prevent an increase in the cost of the product.

[0092] Second Embodiment Figure 12 shows a plan view and a cross-sectional view of the periphery of a first opening in a case of a semiconductor module according to a second embodiment before clamping. Figure 12(A) is a plan view of the periphery of the first opening, and Figure 12(B) is a cross-sectional view showing a cross section taken along line B-B in Figure 12(A). Note that Figure 12(B) also shows an upper mold 60a. In Figure 12, components other than the case 11 are the same as those in the semiconductor module 1 of the first embodiment, and are therefore not shown.

[0093] In the semiconductor module of the second embodiment, the case 11 has a rising region 11b1 formed in the second region 11c1 on the top surface, similar to the semiconductor module 1 of the first embodiment. Furthermore, in the second embodiment, as shown in Fig. 12, the case 11 has an annular first portion 11e1 that is included in the rising region 11b1 on the central axis side of the first opening 11a1, surrounds the first opening 11a1, and is parallel to the top surface of the case 11. Note that the first portion 11e1 may be formed in an arch shape that forms an upwardly convex curved surface relative to the top surface of the case 11 in a cross-sectional view.

[0094] 13A and 13B are a plan view and a cross-sectional view of the first opening and its periphery after clamping in the case of the semiconductor module according to the second embodiment. Fig. 13A is a plan view of the first opening and its periphery, and Fig. 13B is a cross-sectional view taken along line B-B in Fig. 13A. Note that Fig. 13B also shows the upper mold 60a.

[0095] In the process of filling the sealing resin, the upper mold 60a presses the first portion 11e1, thereby pushing the rising region 11b1 together with the first portion 11e1 downward (in the -Z direction) from the top surface of the case 11. As a result, a recessed portion 11d1 that annularly surrounds the first opening 11a1 is formed in the second region 11c1 of the case 11, similar to the semiconductor module 1 of the first embodiment. Furthermore, the first portion 11e1 is inclined downward from the central axis of the first opening 11a1. Then, the sealing resin 40 is filled into the case 11.

[0096] In the semiconductor module of the second embodiment, the first portion 11e1 is provided, and thus the contact area between the second region 11c1 and the upper mold 60a when pressed is larger than that of the semiconductor module 1 of the first embodiment. This makes it possible to further prevent the sealing resin 40 from leaking out of the case 11 through the first opening 11a1.

[0097] (Third embodiment) Figure 14 shows a plan view and a cross-sectional view of the periphery of a first opening in a case of a semiconductor module according to a third embodiment before clamping. Figure 14(A) is a plan view of the periphery of the first opening, and Figure 14(B) is a cross-sectional view showing a cross section taken along line B-B in Figure 14(A). Note that Figure 14(B) also shows an upper mold 60a. In Figure 14, components other than the case 11 are the same as those in the semiconductor module 1 of the first embodiment, and are therefore not shown.

[0098] In the semiconductor module 1 of the third embodiment, the case 11 has a rising region 11b1 formed in the second region 11c1 on the top surface, similar to the semiconductor module 1 of the first embodiment. Also, in the third embodiment, similar to the second embodiment, the rising region 11b1 has an annular first portion 11e1 that is included on the central axis side of the first opening 11a1, surrounds the first opening 11a1, and is parallel to the top surface of the case 11. Note that the first portion 11e1 may be formed in an arch shape that forms an upwardly convex curved surface relative to the top surface of the case 11 in a cross-sectional view.

[0099] Furthermore, in the third embodiment, the second region 11c1 includes a connection region 11c1a that connects to the first region 11c. The upper surface of the connection region 11c1a descends from the same height as the upper surface of the first region 11c toward the central axis of the first opening 11a1 to a height lower than the upper surface of the first region 11c. The thickness of the connection region 11c1a also decreases toward the central axis of the first opening 11a1.

[0100] 15A and 15B are a plan view and a cross-sectional view of the first opening and its periphery after clamping in the case of the semiconductor module according to the third embodiment. Fig. 15A is a plan view of the first opening and its periphery, and Fig. 15B is a cross-sectional view taken along line B-B in Fig. 15A. Note that Fig. 15B also shows the upper mold 60a.

[0101] In the process of filling the sealing resin, the upper mold 60a presses the first portion 11e1, thereby pushing the rising region 11b1 together with the first portion 11e1 downward (in the −Z direction) from the top surface of the case 11. As a result, a recessed portion 11d1 that annularly surrounds the first opening 11a1 is formed in the second region 11c1 of the case 11, similar to the semiconductor module 1 of the first embodiment. Thereafter, the sealing resin 40 is filled into the case 11.

[0102] In the semiconductor module of the third embodiment, the second region 11c1 includes a connection region 11c1a. The upper surface of the connection region 11c1a descends from the same height as the upper surface of the first region 11c toward the central axis of the first opening 11a1 to a height lower than the upper surface of the first region 11c. The thickness of the connection region 11c1a also decreases toward the central axis of the first opening 11a1. By including such a connection region 11c1a, the formed recess 11d1 has a deeper average depth than those formed in the first and second embodiments. Note that the above-described connection region 11c1a may be omitted, and a second region 11c1 having a constant thickness may be connected to the first region 11c at a position lower than the upper surface of the first region 11c.

[0103] Therefore, when the sealing resin 40 is filled into the case 11, the presence of such a recess 11d1 prevents the sealing resin 40 from leaking and spreading outside the recess 11d1 in a planar view more than in the first and second embodiments.

[0104] (Fourth embodiment) Figure 16 shows a plan view and a cross-sectional view of the periphery of a first opening in a case of a semiconductor module according to a fourth embodiment before clamping. Figure 16(A) is a plan view of the periphery of the first opening, and Figure 16(B) is a cross-sectional view showing a cross section taken along line B-B in Figure 16(A). Note that Figure 16(B) also shows an upper mold 60a. In Figure 16, components other than the case 11 are the same as those in the semiconductor module 1 of the first embodiment, and are therefore not shown.

[0105] In the semiconductor module of the fourth embodiment, the case 11 has a rising region 11b1 formed in the second region 11c1 on the top surface, similar to the semiconductor module 1 of the first embodiment. Also, in the fourth embodiment, similar to the second embodiment, the rising region 11b1 has an annular first portion 11e1 that is included on the central axis side of the first opening 11a1, surrounds the first opening 11a1, and is parallel to the top surface of the case 11. Note that the first portion 11e1 may be formed in an arch shape that forms an upwardly convex curved surface relative to the top surface of the case 11 in a cross-sectional view.

[0106] Furthermore, in the fourth embodiment, the second region 11c1 has an annular recessed portion 11d1 that is provided in a position farther from the first opening 11a1 than the rising region 11b1 and that surrounds the first opening 11a1, and a groove 11f1 that is provided in a position farther from the first opening 11a1 than the recessed portion 11d1. The groove 11f1 continuously surrounds the first opening 11a1 and the recessed portion 11d1 in the second region 11c1.

[0107] 17A and 17B are a plan view and a cross-sectional view of the first opening and its periphery after clamping in the case of the semiconductor module according to the fourth embodiment. Fig. 17A is a plan view of the first opening and its periphery, and Fig. 17B is a cross-sectional view taken along line B-B in Fig. 17A. Note that Fig. 17B also shows the upper mold 60a.

[0108] In the process of filling the sealing resin, the upper mold 60a presses the first portion 11e1, thereby pressing the rising region 11b1 together with the first portion 11e1 downward (in the −Z direction) from the top surface of the case 11. As a result, the average depth of the recessed portion 11d1 becomes deeper than before the mold was closed. Then, the sealing resin 40 is filled into the case 11.

[0109] In the semiconductor module of the fourth embodiment, the recess 11d1 formed after mold clamping has a deeper average depth than those formed in the first and second embodiments. Therefore, when the sealing resin 40 is filled into the case 11, the presence of such recess 11d1 prevents the sealing resin 40 from leaking and spreading outside the recess 11d1 in plan view more than in the first and second embodiments.

[0110] Furthermore, in the semiconductor module of the fourth embodiment, the case 11 has a groove 11f1 on the top surface at a position farther from the first opening 11a1 than the recess 11d1. By providing such groove 11f1, the second region 11c1 is more likely to deform when pressed by the upper mold 60a, and the recess 11d1 having a deeper average depth is more likely to be formed.

[0111] Furthermore, even if the sealing resin 40 leaks out of the recessed portion 11d1, the sealing resin 40 enters the groove 11f1, thereby preventing the sealing resin 40 from leaking and spreading on the upper surface of the case 11.

[0112] Incidentally, the case 11 of the third and fourth embodiments has the first portion 11e1, similar to the case 11 of the second embodiment, but the first portion 11e1 may be omitted.

[0113] The first to fourth embodiments may also be combined. For example, as shown in FIG. 6, when the top surface of the case 11 has two first openings 11a1 and 11a2, different embodiments may be applied to the second regions 11c1 and 11c2. For example, the second region 11c1 may be provided with a connection region 11c1a as in the third embodiment, and the second region 11c2 may be provided with a recess 11d1 and a groove 11f1 as in the fourth embodiment.

[0114] In the above description, an example has been described in which the printed circuit board 30 is used as part of the connecting member, but other connecting members or wiring members such as wire bonding or a lead frame may be used instead of the printed circuit board 30.

[0115] (Method of Manufacturing a Semiconductor Module) FIG. 18 illustrates a manufacturing process for a semiconductor module. [Step P1] A step of preparing a component having a case 11 and a second opening is performed. The case 11 has a first region 11c and second regions 11c1 and 11c2 on its top surface, each having a thickness thinner than the first region 11c (see, for example, FIG. 6 ). The case 11 also has first openings 11a1 and 11a2 in the second regions 11c1 and 11c2. Furthermore, the second region 11c1 has a rising region 11b1 that surrounds the first opening 11a1 and, as shown in FIG. 7 , the central axis side of the first opening 11a1 rises upward relative to the top surface of the first region 11c. Similarly, the second region 11c2 has a rising region 11b2 that surrounds the first opening 11a2 and the central axis side of the first opening 11a2 rises upward relative to the top surface of the first region 11c.

[0116] Furthermore, as described in the second embodiment, the case 11 may have an annular first portion 11e1 that is included in the rising region 11b1 on the central axis side of the first opening 11a1, surrounds the first opening 11a1, and is parallel to the top surface of the case 11 (see FIG. 12). Note that the first portion 11e1 may be formed in an arch shape that forms an upwardly convex curved surface relative to the top surface of the case 11 in a cross-sectional view.

[0117] Furthermore, as described in the third embodiment, the second region 11c1 may be connected to the first region 11c via a connection region 11c1a whose thickness decreases from both the front and back sides toward the central axis of the first opening 11a1 (see Figure 14).

[0118] Furthermore, as described in the fourth embodiment, the case 11 may have, in the second region 11c1, a ring-shaped recessed portion 11d1 that is provided around the first opening 11a1 and that is located farther from the first opening 11a1 than the rising region 11b1. The case 11 may also have, in the second region 11c1, a groove 11f1 that is located farther from the first opening 11a1 than the recessed portion 11d1 (see FIG. 16 ).

[0119] Furthermore, the case 11 has terminals 12a to 12c, one end of which protrudes from the inner surface of the case into the inside of the case and the other end of which is exposed to the outside of the case 11. The terminals 12a to 12c are integrally molded with the case 11.

[0120] Components having second openings prepared in process P1 include an insulating circuit board 20 and a printed circuit board 30. As shown in Figures 3B and 7, the insulating circuit board 20 includes conductive pattern layers 20a1-20a3, a metal layer 20b, and an insulating layer 20c sandwiched between the conductive pattern layers 20a1-20a3 and the metal layer 20b. The conductive pattern layers 20a1 and 20a2 also have third openings 20d1 and 20d2 as second openings of the components at the same positions as the first openings 11a1 and 11a2 in a plan view.

[0121] 3A and 7, the printed circuit board 30 has conductive pattern layers 30a1-30a3, a conductive pattern layer 30b, and an insulating layer 30c provided between the conductive pattern layers 30a1-30a3 and the conductive pattern layer 30b. The printed circuit board 30 also has second openings 30d1 and 30d2 as second openings for the components at the same positions as the first openings 11a1 and 11a2 in a plan view.

[0122] [Process P2] A process is carried out in which semiconductor elements 13a-13h are mounted on the insulating circuit board 20. In process P2, with the insulating circuit board 20 set in a joining jig, the semiconductor elements 13a-13h and pin-shaped connecting members 14a, 14b are mounted on the conductive pattern layers 30a1-30a3 via joining members. Furthermore, joining members are placed on the semiconductor elements 13a-13h and the pin-shaped connecting members 14a, 14b to join them to the printed circuit board 30. Note that joining itself does not necessarily have to be performed in process P2.

[0123] [Step P3] Positioning members are inserted into the third openings 20d1 and 20d2 of the insulating circuit board 20, respectively.

[0124] [Step P4] The printed circuit board 30 is mounted on the insulating circuit board 20 so that the positioning members are inserted into the second openings 30d1 and 30d2.

[0125] [Step P5] The case 11 is set so that the positioning members are inserted into the first openings 11a1 and 11a2. This positions the case 11 and the components (insulated circuit board 20 and printed circuit board 30) to be installed inside the case 11 as follows:

[0126] Fig. 19 is a cross-sectional view showing positioning using a positioning member. Fig. 19 shows an example of positioning in the semiconductor module 1 of the first embodiment. A pin-shaped positioning member 50 common to the first opening 11a1, the second opening 30d1, and the third opening 20d1 passes through the first opening 11a1 and the second opening 30d1 and is fixed in a state where it abuts against the bottom of the third opening 20d1 of the insulating circuit board 20. Bonding is performed in this state.

[0127] [Step P6] A bonding step is performed. In this step, terminals 12a-12c of case 11 are bonded onto insulating circuit board 20. Semiconductor elements 13a-13h and pin-shaped connecting members 14a, 14b are bonded to conductive pattern layers 30a1-30a3 of insulating circuit board 20. Furthermore, semiconductor elements 13a-13h and connecting members 14a, 14b are bonded to printed circuit board 30. When solder is used as the bonding member, the bonding step is performed under predetermined reflow conditions. When a sintered material (copper or silver) is used as the bonding member, the bonding step is performed under predetermined sintering conditions.

[0128] [Process P7] The positioning member is removed.

[0129] [Step P8] The transfer molding encapsulation process is performed. The transfer molding encapsulation process is performed as shown in FIGS. 8 and 9 . For example, during the manufacturing of the semiconductor module 1 according to the first embodiment, as shown in FIG. 9 , the upper end 11e of the raised region 11b1 comes into contact with the main surface of the upper mold 60a due to pressure from the upper mold 60a, thereby sealing the gap between the upper surface of the case 11 and the main surface of the upper mold 60a. This prevents the encapsulating resin 40 from leaking out of the case 11 through the first opening 11a1. This prevents the encapsulating resin 40 from spilling out of the case 11, resulting in molding defects. Furthermore, the pressure from the upper mold 60a on the first opening 11a1 forms a recess in the second region 11c1 that surrounds the first opening 11a1. Therefore, even if the encapsulating resin 40 leaks out of the case 11 beyond the upper end 11e, the encapsulating resin 40 flows into the recess. This prevents the sealing resin 40 from leaking and spreading outside the recessed portion in plan view.

[0130] After the sealing resin 40 filled in the case 11 has hardened, the molds (upper mold 60a and lower mold 60b in FIG. 9) are removed to obtain the semiconductor module 1 shown in FIG. 10. The semiconductor modules of the second to fourth embodiments can also be manufactured using the same process as above.

[0131] Although the above example shows the use of a joining material such as solder for joining, joining can also be performed by ultrasonic joining.

[0132] (Modification) FIG. 20 is a diagram showing a modification of a semiconductor module. In FIG. 20, elements that are the same as those shown in FIG. 6 are assigned the same reference numerals. The case 11 in the modified semiconductor module 1b has support members 71-76 extending from the top surface in the -Z direction. These support members 71-76 may be integrally formed on the top surface of the case 11, for example, during molding. As described above, when this case 11 is attached to the insulating circuit board 20 using a positioning member, the tips of the support members 71-76 on the -Z direction abut against the front surface of the insulating circuit board 20, although not shown. By providing these support members 71-76, warping of the top surface of the case 11 can be suppressed. Therefore, as described above, when the top surface of the case 11 is pressed by the upper mold 60a during the sealing process, the top surface of the case 11 is reliably supported from the inside by the support members 71-76, more reliably eliminating any gap between the top surface of the case 11 and the upper mold 60a.

[0133] While the present invention has been described above in terms of one aspect of a semiconductor module and a method for manufacturing the same based on an embodiment, these are merely examples and should not be construed as being limited to the above description. The above merely illustrates the principles of the present invention. Furthermore, numerous modifications and variations are possible for those skilled in the art, and the present invention is not limited to the exact configurations and applications shown and described above. All corresponding modifications and equivalents are deemed to be within the scope of the present invention as defined by the appended claims and their equivalents.

[0134] 1, 1a, 1b Semiconductor module 11 Case 11a1, 11a2 First opening 11b1, 11b2 Rising region 11c First region 11c1, 11c2 Second region 11c1a Connection region 11d1 Recessed portion 11e Upper end portion 11e1 First portion 11f1 Groove 12a to 12c Terminals 13a to 13h Semiconductor element 14a, 14b Connection member 15a, 15b, 15c Joint member 20 Insulated circuit board 20a1 to 20a3, 30a1 to 30a3, 30b Conductive pattern layer 20b Metal layer 20c, 30c Insulating layer 20d1, 20d1 Third opening 30 Printed circuit board 30d1, 30d2 Second opening 40 Sealing resin 50 Positioning member 60a Upper mold 60b Lower mold 71 to 76 Support members

Claims

1. A semiconductor module comprising: a case including, on its top surface, a first region and a second region that is thinner than the first region and has a first opening and a recessed portion that annularly surrounds the first opening; and a sealing resin filled inside the case.

2. The semiconductor module according to claim 1, wherein the case has an upper end flush with the upper surface of the first region, at a position closer to the first opening in a plan view than the recessed portion.

3. The semiconductor module according to claim 1, wherein the case has, in the second region, an annular rising region that rises from the recessed portion toward the central axis of the first opening.

4. The semiconductor module according to claim 3, wherein the case has an annular first portion that is included on the central axis side of the rising region, surrounds the first opening, and is inclined downward from the central axis of the first opening.

5. The semiconductor module described in claim 1, wherein the second region includes a connection region connected to the first region, the upper surface of the connection region descends from the same height as the upper surface of the first region toward the central axis of the first opening to a height lower than the upper surface of the first region, and the thickness of the connection region decreases toward the central axis.

6. The semiconductor module according to claim 1, wherein the case has a groove on the top surface at a position farther from the first opening than the recessed portion.

7. The semiconductor module according to claim 1, wherein the sealing resin is filled up to the upper surface of the inner wall of the case, and the sealing surface at the first opening is flush with the upper surface of the outer wall of the case.

8. The semiconductor module according to claim 1, comprising a semiconductor element and a conductive pattern layer on which the semiconductor element is disposed, at least a portion of an upper surface of which is covered by the case, and the semiconductor element is provided in a region other than directly below the first opening.

9. A semiconductor module as described in claim 1, comprising: a semiconductor element; a plurality of conductive pattern layers; and a connection member that electrically connects any of the plurality of conductive pattern layers to the semiconductor element or electrically connects the plurality of conductive pattern layers to each other, wherein the connection member is provided in an area other than directly below the first opening, or the connection member has a second opening at the same position as the first opening in a plan view.

10. The semiconductor module according to claim 1, wherein said case has a terminal having one end protruding from the inner surface of said case to the inside of said case and the other end exposed to the outside of said case.

11. The semiconductor module according to claim 9, wherein a part of the connection member is a printed circuit board.

12. The semiconductor module according to claim 1, comprising: a semiconductor element; and an insulating circuit board to which the semiconductor element is bonded, which is placed in the case, and which is sealed together with the semiconductor element by the sealing resin within the case, wherein the insulating circuit board includes an insulating layer and a conductive pattern layer to which the semiconductor element is bonded.

13. The semiconductor module according to claim 12, wherein the conductive pattern layer of the insulating circuit board has a third opening at the same position as the first opening in a plan view.

14. The semiconductor module according to claim 13, wherein the third opening does not penetrate the conductive pattern layer.

15. The semiconductor module according to claim 1, wherein the sealing resin is made of a hard resin.

16. A method for manufacturing a semiconductor module, comprising the steps of: preparing a case including, on its top surface, a first region; a second region that is thinner than the first region and has a first opening; and a second region that surrounds the first opening and has a rising region that rises upward relative to the top surface of the first region on the central axis side of the first opening; and a component having a second opening; and pressing the top surface of the case, in which the first opening and the second opening are positioned and the component is housed, with a main surface of a mold that faces the top surface of the case, and filling the case with sealing resin while the rising region is pressed downward.

17. The method for manufacturing a semiconductor module according to claim 16, wherein the sealing resin is filled in a state in which the upper end of the raised region is brought into contact with the main surface of the mold by pressing with the mold.

18. A method for manufacturing a semiconductor module as described in claim 16, wherein in the preparing step, the case has an annular first part that is included on the central axis side of the rising region, surrounds the first opening, and is parallel to the top surface of the case, and in the filling step, the mold presses the first part, thereby pushing the rising region together with the first part downward from the top surface of the case.

19. A method for manufacturing a semiconductor module as described in claim 16, wherein the second region includes a connection region connected to the first region, an upper surface of the connection region descending from the same height as the upper surface of the first region toward the central axis to a height lower than the upper surface of the first region, and a thickness of the connection region decreasing toward the central axis.

20. A method for manufacturing a semiconductor module as described in claim 16, wherein the case has, in the second region, an annular recessed portion surrounding the first opening at a position farther from the first opening than the rising region, and a groove provided at a position farther from the first opening than the recessed portion.

21. The method for manufacturing a semiconductor module according to claim 16, wherein the positioning is performed by inserting a common positioning member into the first opening and the second opening.

22. The method for manufacturing a semiconductor module according to claim 16, wherein the sealing resin is made of a hard resin.

23. A semiconductor module comprising: a case including a first opening on its top surface; a printed circuit board disposed within the case and including a second opening formed in the same position as the first opening in a plan view; and an insulating circuit board disposed within the case below the printed circuit board and including an insulating layer and a conductive pattern layer to which a semiconductor element is bonded, the insulating circuit board including a third opening formed in the conductive pattern layer in the same position as the first opening and the second opening in a plan view.

24. A method for manufacturing a semiconductor module, comprising the steps of: preparing a case having a first opening on its top surface, a printed circuit board having a second opening, a conductive pattern layer having an insulating layer and a semiconductor element bonded thereto, and an insulating circuit board having a third opening formed in the conductive pattern layer; inserting a common positioning member into the first opening, the second opening, and the third opening to position the case, the printed circuit board housed in the case, and the insulating circuit board placed below the printed circuit board, and then joining them; and removing the positioning member, filling the case with sealing resin to seal the printed circuit board and the insulating circuit board.