Semiconductor equipment

Abstract

It suppresses the leakage of oily substances that seep out from the insulating encapsulating resin. [Solution] The semiconductor device comprises a case member 2 having a recess 3, a semiconductor chip 20A provided in the recess 3 of the case member 2, a sealing resin 30 containing an oily substance and provided in the recess 3 of the case member 2 covering the semiconductor chip 20A, a lid member 40 fixed to the case member 2 so as to close the opening side of the recess 3 of the case member 2, and an oily substance absorber 50 disposed between the sealing resin 30 and the lid member 40 and absorbing the oily substance seeping out from the sealing resin 30.

Description

Technical Field

[0004] , , , ,

[0005] , ,

[0001] This technology (the technology of the present disclosure) relates to a semiconductor device, and particularly to a technology effective when applied to a semiconductor device having a sealing resin provided to cover a semiconductor chip within a recess of a case member.

Background Art

[0002] A semiconductor device includes a case member having a recess, a sealing resin provided to cover a semiconductor chip within the recess of the case member, and a lid member fixed to the case member so as to close an opening side of the recess of the case member. As technologies related to this type of semiconductor device, technologies for preventing external leakage of the sealing resin and technologies for preventing external leakage of oil and grease components that have leaked out from the sealing resin are disclosed in Patent Documents 1 to 4.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID= forty-six]] An object of this technology is to provide a novel technology capable of suppressing external leakage of oil components that have leaked out from the sealing resin.

Means for Solving the Problems

[0005] (1) To achieve the above object, a semiconductor device according to one aspect of this technology is a case member having a recess, A semiconductor chip provided in the recess of the above-mentioned case member, A sealing resin containing an oily component and provided covering the semiconductor chip within the recess of the case member, A lid member is fixed to the case member so as to close the opening side of the recess of the case member, The device comprises an oil absorber positioned between the sealing resin and the lid member, which absorbs oily substances that seep out from the sealing resin.

[0006] (2) In addition, in a semiconductor device according to one aspect of this technology, The oil absorbent described above is a plate-shaped inner lid member having a recess on the surface facing the sealing resin that is recessed in a direction away from the sealing resin.

[0007] (3) In addition, in a semiconductor device according to one aspect of this technology, The above-mentioned oil absorber is a plate-shaped porous insulating member having voids inside. [Effects of the Invention]

[0008] According to one aspect of this technology, it is possible to suppress the external leakage of oil components that seep out from the sealing resin. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic plan view showing the external configuration of a semiconductor device according to the first embodiment of this technology. [Figure 2] This is a schematic longitudinal cross-sectional view showing the longitudinal structure along the II-II section in Figure 1. [Figure 3] This is a magnified longitudinal cross-sectional view of a key part of Figure 2. [Figure 4] This is a schematic longitudinal cross-sectional view of a key part illustrating an example of a state in which the sealing resin comes into contact with the inner lid member due to thermal expansion in the first embodiment of this technology. [Figure 5] This is a plan view showing the planar pattern of recesses provided on the sealing resin side surface of the inner lid member. [Figure 6]Variant 1-1 according to the first embodiment of the present technology, which is a plan view showing the planar pattern of the concave portion of the inner lid member. [Figure 7] Variant 1-2 according to the first embodiment of the present technology, which is a plan view showing the planar pattern of the concave portion of the inner lid member. [Figure 8] Variant 1-3 according to the first embodiment of the present technology, which is a plan view showing the planar pattern of the concave portion of the inner lid member. [Figure 9] Variant 1-4 according to the first embodiment of the present technology, which is a plan view showing the planar pattern of the concave portion of the inner lid member. [Figure 10] A longitudinal sectional view schematically showing the internal structure of a semiconductor device according to the second embodiment of the present technology. [Figure 11] A longitudinal sectional view of a main part obtained by enlarging a part of FIG. 9. [Figure 12] In the second embodiment of the present technology, it is a longitudinal sectional view of a main part schematically showing an example of a state where a sealing resin contacts a porous insulating member due to thermal expansion. [Figure 13] A plan view schematically showing the external configuration of a semiconductor device according to the third embodiment of the present technology. [Figure 14] A plan view schematically showing the external configuration of a semiconductor device according to the fourth embodiment of the present technology.

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present technology will be described in detail with reference to the drawings. In the description of the drawings referred to in the following explanation, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thicknesses of each layer, etc. are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following explanation.

[0011] Of course, there are also parts where the dimensional relationships and ratios are different between the drawings. Also, the effects described in this specification are merely illustrative and not limiting, and there may be other effects.

[0012] In addition, the following embodiments illustrate devices and methods for embodying the technical idea of the present technology, and do not specify the configuration as the following. That is, the technical idea of the present technology can be variously modified within the technical scope described in the claims.

[0013] Also, the definitions of directions such as "up", "down", "vertical", "left", "right", "horizontal" in the following description are merely definitions for convenience of explanation and do not limit the technical idea of the present technology. For example, if the object is rotated 90° and observed, the vertical becomes horizontal and is read as such, and if it is rotated 180° and observed, the vertical is inverted and read, of course.

[0014] Also, in the following description, the "upper surface portion" and "lower surface portion" may be read as "front surface portion" and "back surface portion" respectively. The "first main surface portion" and "second main surface portion" of each member are the main surface portions (main surfaces) located on opposite sides of each other. For example, if the "first main surface portion" is the upper surface portion, the "second main surface portion" is the lower surface portion. Also, the "first main surface portion" and "second main surface portion" may be read as "one main surface portion" and "the other main surface portion" respectively.

[0015] Also, in the following embodiments, in three directions orthogonal to each other in space, the first direction and the second direction orthogonal to each other in the same plane are defined as the X direction and the Y direction respectively, and the third direction orthogonal to each of the first direction and the second direction is defined as the Z direction. And in the following embodiments, the thickness direction of the case member described later will be described as the Z direction.

[0016] Furthermore, in this specification, when the transistor mounted on the transistor chip is a field-effect transistor (FET) or an electrostatic induction transistor (SIT), the first main electrode means either the source electrode or the drain electrode, the second main electrode means the other remaining electrode, and the control electrode means the gate electrode. When the transistor mounted on the transistor chip is a bipolar junction transistor (BJT), the first main electrode means either the emitter electrode or the collector electrode, the second main electrode means the other remaining electrode, and the control electrode means the base electrode. When the transistor mounted on the transistor chip is an insulated gate bipolar transistor (IGBT), the first main electrode means either the emitter electrode or the collector electrode, the second main electrode means the other remaining electrode, and the control electrode means the gate electrode. In the following embodiments, we will focus on a MISFET, a type of insulated-gate field-effect transistor, as the transistor mounted on the semiconductor chip. Therefore, the first main electrode will be described as the source electrode, the second main electrode as the drain electrode, and the control electrode as the gate electrode.

[0017] Furthermore, in the following embodiments, a plan view refers to the view of the semiconductor device from the Z direction. A cross-sectional view refers to the view of a cross section along the Z direction from a direction perpendicular to this cross section (the Z direction).

[0018] [First Embodiment] In this first embodiment, we will describe an example in which this technology is applied to a semiconductor device as a power device incorporated into a power conversion device that converts power from direct current to alternating current. Furthermore, in this first embodiment, we will describe a case in which a plate-shaped inner lid member having a recess on the surface facing the sealing resin is used as the oil component absorber of this technology.

[0019] ≪Overall Configuration of Semiconductor Device≫ First, let's explain the overall configuration of the semiconductor device. As shown in Figures 1 and 2, the semiconductor device 1A according to the first embodiment of this technology comprises a case member 2 having a recess 3, a semiconductor chip 20 and bonding wires 25 provided in the recess 3 of the case member 2, and a sealing resin 30 containing an oily component and provided covering the semiconductor chip 20 in the recess 3 of the case member 2. Furthermore, the semiconductor device 1A according to the first embodiment of this technology further includes a lid member 40 fixed to the case member 2 so as to close the opening side of the recess 3 of the case member 2, and an inner lid member 51 which is disposed between the sealing resin 30 and the lid member 40 and serves as an oil absorber 50 that absorbs oily substances seeping out from the sealing resin 30. Furthermore, the semiconductor device 1A according to the first embodiment of this technology further comprises an insulating circuit board 10 provided in a recess 3 of the case member 2, on which semiconductor chips 20 and 25 are mounted. Furthermore, the semiconductor device 1A according to the first embodiment of this technology includes a positive terminal 6P, a negative terminal 6N, three output terminals 8U, 8V, and 8W, and a plurality of control terminals (auxiliary terminals) 9 as external connection terminals integrally provided with the frame 5 of the case member 2. These external connection terminals are electrically connected to a semiconductor chip, which will be described later.

[0020] <Case components> As shown in Figure 2, the case member 2 has the recess 3 described above, and further includes a heat sink 4 and a frame 5 fixed to the heat sink 4 and surrounding the semiconductor chip 20. The recess 3 of the case member 2 is composed of the heat sink 4 and the frame 5.

[0021] As shown in Figure 1, the frame 5 has a rectangular shape in plan view. Although not shown in detail, the outer edge of the frame 5 in plan view includes two long sides that are located opposite each other in the short side direction (Y direction) and extend in the long side direction (X direction), which is perpendicular to the Y direction, and two short sides that are located opposite each other in the long side direction (X direction) and extend in the Y direction. Furthermore, as explained with reference to Figure 2, the frame 5 has a main surface and a back surface that have thickness in the Z direction, which is perpendicular to the X and Y directions, and are located opposite each other.

[0022] As shown in Figure 2, the heat sink 4 is provided on the back side of the frame 5. Although not shown in detail, the heat sink 4 has a rectangular shape in plan view, for example, a rectangle similar to the plan view of the frame 5. Furthermore, the external dimensions of the heat sink 4 in plan view are approximately the same as the external dimensions of the frame 5 in plan view.

[0023] The heat sink 4, like the frame 5, has an outer edge in plan view that includes two long sides and two short sides. Referring to Figure 2, it has thickness in the Z direction, which is perpendicular to the X and Y directions, and has a main surface and a back surface located on opposite sides of each other.

[0024] The heat sink 4 is mainly composed of a metal or composite material with excellent thermal conductivity. The metal is, for example, copper, aluminum, or an alloy containing at least one of these. It may also be a composite material containing a metal such as aluminum or magnesium and silicon carbide. The thickness of the heat sink 4 is preferably 1.0 mm or more and 20.0 mm or less. To improve corrosion resistance, the surface of the heat sink 4 may be plated. In this case, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy.

[0025] The frame 5 is made of, for example, a thermoplastic resin. Examples of thermoplastic resins that can be used include polyphenylene sulfide resin, polybutylene terephthalate resin, polybutylene succinate resin, polyamide resin, and acrylonitrile butadiene styrene resin. Fillers may be added to such resins. Examples of fillers that can be used include glass, silicon oxide, aluminum oxide, silicon nitride, and boron nitride. The frame 5 is formed by filling such a resin into a predetermined mold, allowing it to solidify, and then removing the mold.

[0026] As shown in Figure 2, the frame 5 is bonded and fixed to the main surface of the heat sink 4 via an adhesive (not shown) on its back surface. By bonding and fixing the frame 5 to the heat sink 4, a case member 2 having a recess 3 is formed. The adhesive is mainly composed of an organic adhesive. The organic adhesive has a heat resistance temperature of about 100°C to 200°C. Specifically, it is an epoxy, silicone, or acrylic adhesive. The adhesive may be in paste or sheet form.

[0027] As shown in Figure 2, a stepped portion 5c is provided on the main surface side of the frame 5, which is lower than the main surface. Although not shown in detail, this stepped portion 5c is formed in an annular shape along the outer edge of the frame 5 in a plan view and is connected to the recess 3 on the opening side of the recess 3. The cover member 40 is fitted into this stepped portion 5c.

[0028] <Insulated Circuit Board> As shown in Figure 2, the insulated circuit board 10 includes an insulating plate 11, a circuit pattern 12, and a metal plate 13. Each of the insulating plate 11 and the metal plate 13 has a rectangular planar shape, for example, a rectangle, when viewed from above. The planar size of the metal plate 13 is smaller than that of the insulating plate 11, and in planar view, the outer edge (contour) of the insulating plate 13 is located inside the outer edge (contour) of the insulating plate 11. Each of the insulating plate 11, the circuit pattern 12, and the metal plate 13 has a main surface and a back surface that are located opposite each other in their respective thickness directions (Z direction).

[0029] The insulating plate 11 is made of a material that has insulating properties and excellent thermal conductivity. Such an insulating plate 11 is made of, for example, ceramics or insulating resin. Ceramics include aluminum oxide, aluminum nitride, silicon nitride, etc. Insulating resins include, for example, paper phenolic substrates, paper epoxy substrates, glass composite substrates, and glass epoxy substrates. The thickness of the insulating plate 11 is, for example, 0.2 mm or more and 2.5 mm or less.

[0030] As shown in Figure 2, the circuit pattern 12 is provided on the main surface side of the insulating plate 11, and the back side of the circuit pattern 12 is joined to the main surface side of the insulating plate 11. The circuit pattern 12 is made of a metal with excellent conductivity. Such a metal is copper, aluminum, or an alloy mainly composed of at least one of these. The thickness of the circuit pattern 12 is, for example, 0.1 mm or more and 2.0 mm or less. To improve corrosion resistance, the surface of the circuit pattern 12 may be plated. In this case, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy.

[0031] The circuit pattern 12 is formed on the main surface side of the insulating plate 11 as follows: A metal plate is formed on the main surface side of the insulating plate 11, and a circuit pattern 12 of a predetermined shape is obtained by performing a process such as etching on this metal plate. Alternatively, the circuit pattern 12 cut out from a metal plate in advance may be pressed onto the main surface side of the insulating plate 11.

[0032] Note that the circuit pattern 12 shown in Figure 2 is just one example, and the number, shape, and position of the circuit pattern 12 may be selected as appropriate.

[0033] As shown in Figure 2, the metal plate 13 is provided on the back side of the insulating plate 11, and the back side of the metal plate 13 is joined to the back side of the insulating plate 11. In plan view, the metal plate 13 overlaps with the insulating plate 11 and is formed over the entire area of ​​the insulating plate 11 except for the peripheral edge.

[0034] The metal plate 13 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. The thickness of the metal plate 13 is, for example, 0.1 mm or more and 2.5 mm or less. To improve corrosion resistance, the surface of the metal plate 13 may be plated. In this case, the plating material used is, for example, nickel, nickel-phosphorus alloy, or nickel-boron alloy.

[0035] The metal plate 13 is formed on the back side of the insulating plate 11 as follows. That is, a metal plate is formed on the back side of the insulating plate 11, and the metal plate 13 is obtained by applying a treatment such as etching to this metal plate. Alternatively, a metal plate 13 cut out from a metal plate in advance may be pressed onto the back side of the insulating plate 11. The metal plate 13 provided on the back side of the insulating plate 12 in this way may have rounded corners or rounded corners.

[0036] As the insulating circuit board 10 having such a configuration, a DCB (Direct Copper Bonding) board, an AMB (Active Metal Brazed) board, or a resin insulating board may be used. The heat generated by the semiconductor chip 20 is dissipated to the outside by being conducted to the heat sink 4 via the circuit pattern 11, insulating board 12, and metal plate 13.

[0037] Note that the insulating circuit board 10 is not limited to one as shown in Figure 2, but may be arranged in multiples as needed.

[0038] <Semiconductor chips> As shown in Figure 2, semiconductor chips 20A and 20B are mounted on the circuit pattern 12 of the insulated circuit board 10. Multiple instances of each of the semiconductor chips 20A and 20B are mounted. Although Figure 2 illustrates three semiconductor chips 20A and two semiconductor chips 20B, the number of each of the semiconductor chips 20A and 20B is not limited to the numbers shown in Figure 2.

[0039] The semiconductor chip 20A shown in Figure 2 includes a switching element as a power device element composed of a semiconductor such as silicon, silicon carbide, or gallium nitride. On the other hand, the semiconductor chip 20B shown in Figure 2 includes a diode element as a power device element composed of a semiconductor such as silicon, silicon carbide, or gallium nitride.

[0040] Switching elements include, for example, insulated-gate bipolar transistors (IGBTs) and insulated-gate field-effect transistors (MISFETs). Such a semiconductor chip 20A has, for example, a main surface and a back surface located on opposite sides of each other in the thickness direction (Z direction) of the semiconductor chip 20A, a control electrode and a first main electrode provided on the main surface, and a second main electrode provided on the back surface. If the switching element is an IGBT, for example, the first main electrode functions as the emitter electrode, the second main electrode functions as the collector electrode, and the control electrode functions as the gate electrode. If the switching element is a MISFET, for example, the first main electrode functions as the source electrode, the second main electrode functions as the drain region, and the control electrode functions as the gate electrode.

[0041] The diode element is, for example, a Schottky barrier diode (SBD) or a PiN (P-intrinsic-N) diode, which is a Free Wheeling Diode (FWD). Such a semiconductor chip 20B has a main surface portion and a back surface portion located on opposite sides of each other in the thickness direction (Z direction) of the semiconductor chip 20B, a cathode electrode as a first main electrode provided on the main surface portion, and an anode electrode as a second main electrode provided on the back surface portion.

[0042] Each of the semiconductor chips 20A and 20B is electrically and mechanically joined to a predetermined circuit pattern 12 on its back side via a bonding material (not shown). The bonding material is solder or a metal sintered body. Lead-free solder is used. Lead-free solder mainly consists of an alloy containing at least two of the following: tin, silver, copper, zinc, antimony, indium, and bismuth. Furthermore, the solder may contain additives. Additives include, for example, nickel, germanium, cobalt, or silicon. The inclusion of additives in the solder improves wettability, gloss, and bonding strength, thereby improving reliability. The metal used in the metal sintered body is, for example, silver or a silver alloy.

[0043] Alternatively, semiconductor chips including an RC (Reverse-Conducting)-IGBT, which combines the functions of IGBT and FWD, may be used instead of semiconductor chips 20A and 20B.

[0044] <External connection terminals> As shown in Figure 1, the positive terminal 6P and the negative terminal 6N, which are external connection terminals, are located on one of the two short sides included in the outer periphery of the frame 5 in a plan view (the left side in Figure 1), and are arranged at a predetermined interval in the direction of extension of this one short side.

[0045] As shown in Figure 1, each of the three output terminals 8U, 8V, and 8W, which are external connection terminals, is located on one of the two long sides included in the outer periphery of the frame 5 in a plan view (the lower side in Figure 1), and is arranged at a predetermined interval in the direction of extension of this one long side.

[0046] As shown in Figure 1, each of the multiple control terminals 9, which are external connection terminals, is provided on the other long side (upper side in Figure 1) of the two long sides included in the outer periphery of the frame 5 in a plan view, and is arranged at predetermined intervals in the direction of extension of this other long side.

[0047] As shown in Figure 2, the negative terminal 6N extends both inside and outside the frame 5 in the thickness direction (Z direction), with one end protruding outward from the main surface of the frame 5. Although not shown, the positive terminal 6P, the three output terminals 8U, 8V, and 8W, and the multiple control terminals 9 also extend both inside and outside the frame 5 in the thickness direction (Z direction), similar to the negative terminal 6N, with one end protruding outward from the main surface of the frame 5.

[0048] As shown in Figure 2, the other end of the negative terminal 6N is bent inward into the frame 5 and exposed from the frame 5 as a connection point. Although not shown, the other ends of the positive terminal 6P, the three output terminals 8U, 8V, and 8W, and the multiple control terminals 9 are also bent inward into the frame 5 and exposed from the frame 5 as connection points, similar to the other end of the negative terminal 6N.

[0049] <Electrical connection between external connection terminals and semiconductor chips> The external connection terminals, namely the positive terminal 6P, the negative terminal 6N, the three output terminals 8U, 8V, and 8W, and the multiple control terminals 9, are not shown in detail, but are electrically connected to the semiconductor chips 20A and 20B via bonding wires 25, as shown in Figures 2 and 3, as connecting members. Instead of bonding wires 28, plate-shaped leads can also be used as connecting members.

[0050] <Lid component> As shown in Figures 1 and 2, the lid member 40 is a flat plate having a main surface and a back surface located on opposite sides in the thickness direction (Z direction) of the lid member 40. The outer periphery of the lid member 40 in plan view is the same as the outer periphery of the stepped portion 5c of the frame body 5. In this first embodiment, the lid member 40 is fitted into the stepped portion 5c of the frame body 5, and the lid member 40 is fixed to the stepped portion 5c of the frame body 5 by the fitting force between the frame body 5 and the lid member 40. This fitting force is generated by the elastic deformation of at least one of the frame body 5 and the lid member 40. The lid member 40 is made of the same material as the frame body 5, for example.

[0051] <Sealing resin> As shown in Figure 2, the sealing resin 30 is filled into the recess 3 of the case member at a predetermined distance from the back surface of the lid member 40. The sealing resin 30 then covers and seals the insulating circuit board 10, semiconductor chips 20A and 20B, bonding wires 25, etc., which are placed in the recess 3 of the case member 2. In other words, the sealing resin 30 is filled into the recess 3 of the case member 2 to a height that is sufficient to seal the insulating circuit board 10, semiconductor chips 20A and 20B, and bonding wires 25.

[0052] The sealing resin 30 mainly consists of, for example, silicone gel. The silicone gel contains liquid low molecular weight siloxane as an oily component. The liquid low molecular weight siloxane is present in an amount of 20% to 30%. The liquid low molecular weight siloxane is intertwined in a chain-like structure and also fills the gaps between the polymer siloxane. The liquid low molecular weight siloxane functions as a buffer against thermal stress caused by temperature changes. Therefore, the liquid low molecular weight siloxane can maintain its insulating function against temperature changes in the sealing resin 30.

[0053] <Inner cover component> The inner lid member 51 shown in Figure 2, although not illustrated in detail, is composed of a flat plate. As shown in Figure 2, the inner lid member 51 is positioned between the sealing resin 30 and the lid member 40 within the recess 3 of the case member 2 (inside the frame 5). The inner lid member 51 is supported by the lid member 40 via an elastic body 55.

[0054] Although not shown in detail, the inner lid member 51 has the same planar shape as the opening side (main surface side of the frame 5) of the recess 3 of the case member 2, and has a planar size slightly smaller than the planar size of the recess 3. The inner lid member 51 is slidable inside the recess 3 in the thickness direction (Z direction) of the case member 2.

[0055] Here, the semiconductor chips 20A and 20B and bonding wires 25 shown in Figure 3 have high current densities and generate a large amount of heat. As a result, the sealing resin 30 expands due to the heat generated in these areas, and as shown in Figure 4, it partially bulges. When the bulging portion of the sealing resin 30 comes into contact with the inner lid member 51 and generates an upward pushing force that pushes the inner lid member 51 upward, the elastic body 55 elastically deforms due to the pressing force of the sealing resin 30 pushing up the inner lid member 51. The inner lid member 51 then moves upward while sliding along the inner wall surface of the recess 3 of the case member 2 (the inner wall surface of the frame) due to the elastic deformation of the elastic body 55. In other words, the inner lid member 51 is supported by the lid member 40 via the elastic body 55, which elastically deforms due to the upward pushing force acting on the inner lid member 51 due to the thermal expansion of the sealing resin 30. The elastic body 55 is not limited to this, but for example, a porous material such as a sponge with internal voids is used.

[0056] As shown in Figure 3, the inner lid member 51 has a first surface portion 52a and a second surface portion 52b located on opposite sides of each other in the thickness direction (Z direction) of the inner lid member 51. Furthermore, as shown in Figures 2 and 3, the inner lid member 51 has a recess 53 in the first surface portion 52a on the sealing resin 30 side, which is recessed in a direction away from the sealing resin 30. The recess 53 is recessed from the first surface portion 52a toward the second surface portion 52b, with the first surface portion 52a of the inner member 51 as the reference surface.

[0057] As shown in Figure 3, the inner lid member 51 has multiple recesses 53. The multiple recesses 53 are not limited to these, but for example, as shown in Figure 5, they are spaced apart from each other and arranged in a concentric ring shape. The multiple recesses 53 are located away from the outer edge of the inner lid member 51 in a plan view and are located inside the outer edge of the inner lid member 51. The inner lid member 53 configured in this way can store and absorb oily substances that seep from the inside of the sealing resin 30 to the resin surface in the recesses 53.

[0058] Here, if the inner lid member 51 is in contact with the resin surface of the sealing resin 30 from the beginning, oily components from inside the sealing resin 30 tend to seep out into the interface between the sealing resin 30 and the inner lid member 51. Therefore, as shown in Figure 3, it is preferable to separate them to the extent that the sealing resin 30 expands due to heat and comes into contact with the inner lid member 51. Specifically, the separation dimension t1 between the resin surface of the sealing resin 30 and the first surface portion 52a of the inner lid member 51 is preferably 0.5 mm or more and 2.0 mm or less.

[0059] <Other configurations> As shown in Figure 2, the frame 5 has a protrusion 5d that projects inward (into the recess 3) from the frame 5. A semiconductor chip 23 is provided on this protrusion 5d via a wiring board 22. A control circuit is mounted on this semiconductor chip 23. Therefore, the amount of heat generated by the semiconductor chip 23 due to the operation of this control circuit is small, as is the amount of heat generated by the semiconductor chips 20A and 20B on which the power devices are mounted. In other words, each of the semiconductor chips 20A and 20B on which the power devices are mounted generates more heat than the semiconductor chip 23 on which the control circuit is mounted.

[0060] As shown in Figure 2, each of the semiconductor chips 23 and the wiring board 22 is covered with sealing resin 30, similar to the semiconductor chips 20A, 20B and the insulating circuit 10. Furthermore, each of the semiconductor chips 23 and the wiring board 22 is superimposed on the inner cover member 51 in a plan view, similar to the semiconductor chips 20A, 20B and the insulating circuit 10.

[0061] <<Main effects of the first embodiment>> Next, the main effects of this first embodiment will be described. The semiconductor device 1A according to this first embodiment uses, for example, a silicone gel sealing resin 30. In the case of such a sealing resin 30, oily components seep out from the inside of the sealing resin 30 to the resin surface over time. In the case of a conventional semiconductor device, as explained using the reference numerals shown in Figure 3 of this first embodiment, the oily components that seep out to the resin surface of the sealing resin 30 travel along the inner wall surface of the frame 5 and then leak to the outside through the interface between the stepped portion of the frame 5 and the lid member 40.

[0062] In contrast, in this first embodiment, an inner lid member is provided as an oil absorber 50 that is placed between the sealing resin 30 and the lid member and absorbs oily components that seep from the inside of the sealing resin to the resin surface. The inner lid member 51 has a recess 53 on the first surface portion 52a on the sealing resin 30 side that is recessed in a direction away from the sealing resin 30. The inner lid member 53 configured in this way can store and absorb oily components that seep from the inside of the sealing resin 30 to the resin surface in the recess 53. Therefore, according to the semiconductor device 1A of this first embodiment, it is possible to suppress external leakage of oily components that seep from the inside of the sealing resin 30 to the outside of the semiconductor device 1A.

[0063] In the first embodiment described above, the case in which the lid member 40 is fixed to the stepped portion 5c of the frame 5 by the fitting force between the frame 5 and the lid member 5c was explained. However, the outer peripheral edge of the lid member 40 can also be bonded and fixed to the stepped portion 5c of the frame 5 with adhesive interposed. In this adhesive bonding method, if the entire outer peripheral edge of the lid member 40 is bonded and fixed to the stepped portion of the frame 5, the sealing resin 30 will expand due to the heat generated by bonding wires 25 and semiconductor chips 20A, 20B, which have a high current density. Furthermore, the gaseous components inside the semiconductor device will expand as they are sealed, increasing the pressure inside the case member 2, which can cause problems such as the lid exploding and coming off. Therefore, it is necessary to leave an area on the outer peripheral edge of the lid member 51 that is not bonded to secure a passage for the gas to escape. In other words, even when the outer peripheral edge of the lid member 40 is bonded and fixed to the stepped portion 5c of the frame 5, a passage is necessary, and the oily component of the sealing resin 30 will leak to the outside of the semiconductor device through this passage. Therefore, even when the outer peripheral edge of the lid member 40 is adhesively fixed to the stepped portion 5c of the frame 5, by providing the inner lid member 51 of this technology, it is possible to suppress external leakage of oil components that have seeped from the inside of the sealing resin 30 to the resin surface and leak out to the outside of the semiconductor device 1A.

[0064] Furthermore, as shown in Figure 1, the frame 5 has a thinner wall thickness in the portion 5f where the mounting holes 5e are provided compared to other portions. In this portion 5f, adhesive is not applied because there is a concern that the adhesive may easily seep into the mounting holes 5e and cause deviations in the mounting hole dimensions. Even in such cases, by providing the inner cover member 51 of this technology, it is possible to suppress external leakage of oil components that have seeped from the inside of the sealing resin 30 to the outside of the semiconductor device.

[0065] Furthermore, in the first embodiment described above, the semiconductor chip 23 and the wiring board 22 are configured to overlap with the inner cover member 51 in a plan view, similar to the semiconductor chips 20A, 20B and the insulating circuit 10. However, since the heat generated by the semiconductor chip 23 is smaller than that generated by the semiconductor chips 20A and 20B, the inner cover member does not need to be provided in the portion that overlaps with the semiconductor chip 23 in a plan view. In other words, the inner cover member 51 may be selectively provided in the region that overlaps with a component that generates a large amount of heat among the components sealed with the sealing resin 30.

[0066] <<Variations of the First Embodiment>> In the first embodiment described above, the planar pattern of the recess 53 provided on the first surface portion 52a of the inner lid member 51 was described in which a plurality of recesses 53 are spaced apart from each other and configured in a concentric ring shape. However, the recess 53 of this technology is not limited to the first embodiment described above.

[0067] <Variation 1-1> Figure 6 is a modified example 1-1 according to the first embodiment of the present technology, and is a plan view showing the planar pattern of the recess of the inner lid member. As shown in Figure 6, in this modified example 1-1, multiple recesses 53 are provided in a dot-like pattern. In this modified example 1-1 as well, the multiple recesses 53 are provided away from the outer edge of the inner lid member 51 in a plan view, and are also provided inside the outer edge of the inner lid member 51. In this modified example 1-1, the same effects as those of the first embodiment described above can be obtained. It is being done.

[0068] <Variation 1-2> Figure 7 is a plan view showing a modified example 1-2 of the first embodiment of the present technology, which shows the planar pattern of the recess of the inner lid member. As shown in Figure 7, in this modified example 1-2, a plurality of recesses 53 extending in the X direction are arranged at predetermined intervals in the Y direction. In this modified example 1-2 as well, the plurality of recesses 53 are provided away from the outer peripheral edge of the inner lid member 51 in a plan view, and are provided inside the outer peripheral edge of the inner lid member 51. In this modified example 1-2, the same effects as those of the first embodiment described above can be obtained. It is being done.

[0069] <Variation 1-3> Figure 8 is a plan view showing a modified example 1-3 of the first embodiment of the present technology, which shows the planar pattern of the recess of the inner lid member. As shown in Figure 8, in this modified example 1-3, a plurality of recesses 53 extending in the Y direction are arranged at predetermined intervals in the X direction. In this modified example 1-3 as well, the plurality of recesses 53 are provided away from the outer peripheral edge of the inner lid member 51 in a plan view, and are provided inside the outer peripheral edge of the inner lid member 51. In these modified examples 1-3, the same effects as those of the first embodiment described above can be obtained. It is being done.

[0070] <Variation 1-4> Figure 9 is a plan view showing a modified example 1-4 of the first embodiment of the present technology, which shows the planar pattern of the recess of the inner lid member. As shown in Figure 9, in this modified example 1-3, the recess 53 is formed by a planar pattern that extends in a continuous spiral shape. In this modified example 1-4 as well, the recess 53 is provided away from the outer edge of the inner lid member 51 in a plan view, and is provided inside the outer edge of the inner lid member 51. In these modified examples 1-4, the same effects as those of the first embodiment described above can be obtained.

[0071] The spiral-shaped recess 53 may be configured to be separated into several parts.

[0072] [Second Embodiment] In this second embodiment, we will describe a case in which a porous insulating member is used as the oil component absorber. Figure 10 is a schematic longitudinal cross-sectional view showing the internal structure of a semiconductor device according to the second embodiment of this technology. Figure 11 is a magnified longitudinal cross-sectional view of a key part of Figure 9. Figure 12 is a schematic longitudinal cross-sectional view of a key part illustrating an example of a state in which the sealing resin comes into contact with the porous insulating member due to thermal expansion in a second embodiment of this technology.

[0073] The semiconductor device 1B according to the second embodiment of this technology has basically the same configuration as the semiconductor device 1A according to the first embodiment described above, but differs in the following configuration.

[0074] That is, as shown in Figures 10 and 11, the semiconductor device 1B according to the second embodiment of this technology is provided with a plate-shaped porous insulating member 56 having internal voids as an oil absorber 50 that is placed between the sealing resin 30 and the lid member 40 and absorbs oily substances seeping out from the sealing resin 30, instead of the plate-shaped inner lid member 51 shown in Figure 2 of the first embodiment described above. The porous insulating member 56, although not shown in detail, is composed of a flat plate. As shown in Figures 10 and 11, the porous insulating member 56 is positioned between the sealing resin 30 and the lid member 40 within the recess 3 of the case member 2 (inside the frame 5). The porous insulating member 56 is directly supported by the lid member 40.

[0075] Although not shown in detail, the porous insulating member 56 differs from the inner lid member 51 of the first embodiment described above in that it has the same planar shape as the opening side (main surface side of the frame 5) of the recess 3 of the case member 2, and has a planar size that is approximately the same as the planar size of the recess 3.

[0076] Here, the semiconductor chips 20A and 20B and bonding wire 25 shown in Figure 11 have high current densities and generate a large amount of heat. As a result, the sealing resin 30 expands due to the heat generated in these areas, and as shown in Figure 12, it partially bulges. When the bulging portion of the sealing resin 30 comes into contact with the inner lid member 51 and generates an upward pushing force that pushes the porous insulating member 56 upward, the porous insulating member 56 elastically deforms due to the pressing force exerted by the sealing resin 30. In other words, the porous insulating member 56 is an elastic body that elastically deforms due to the upward pushing force acting on it due to the thermal expansion of the sealing resin 30. The porous insulating member 56 is not limited to this, but for example, sponge is used.

[0077] The porous insulating member 56 constructed in this manner can absorb oily substances that seep from inside the sealing resin 30 to the resin surface.

[0078] Here, similar to the inner lid member 51 described above, if the porous insulating member 56 is initially in contact with the resin surface of the sealing resin 30, oily components from inside the sealing resin 30 tend to seep into the interface between the sealing resin 30 and the porous insulating member 56. Therefore, as shown in Figure 8, it is preferable to separate the sealing resin 30 to the extent that it expands due to heat and comes into contact with the porous insulating member 56. Specifically, the separation dimension t1 between the resin surface of the sealing resin 30 and the porous insulating member 56 is preferably 0.5 mm or more and 2.0 mm or less.

[0079] In this second embodiment of the porous insulating member 56, the oily components that seep out from inside the sealing resin 30 to the resin surface can be absorbed into the recesses 53, thereby suppressing external leakage of the oily components that seep out from inside the sealing resin 30 to the outside of the semiconductor device 1B.

[0080] In addition, in this second embodiment, the porous insulating member 56 may also be selectively provided in areas that overlap with components that generate a large amount of heat, among the components sealed with the sealing resin 30.

[0081] [Third Embodiment] Figure 13 is a schematic plan view showing the external configuration of a semiconductor device according to the third embodiment of this technology.

[0082] The semiconductor device 1C according to the third embodiment of this technology has basically the same configuration as the semiconductor device 1A according to the first embodiment described above, but differs in the following configuration.

[0083] In other words, as shown in Figure 13, the semiconductor device 1C according to this third embodiment is configured such that the frame 5 and the lid member 40 are bonded together by applying adhesive 57 from the outside to the boundary between the frame 5 and the lid member 40 using a dispenser in a plan view. In this semiconductor device 1C as well, it is necessary to provide an area 58 that is not bonded with adhesive 57 to secure a flow passage connecting the recess 3 and the outside. Therefore, even in the semiconductor device 1C in which the frame 5 and the lid member 40 are bonded together by applying adhesive 57 from the outside to the boundary between the frame 5 and the lid member 40 using a dispenser in a plan view, by providing the inner lid member 51 of this technology, it is possible to suppress external leakage of oil components that have seeped from the inside of the sealing resin 30 to the outside of the semiconductor device 1C.

[0084] [Fourth Embodiment] Figure 14 is a schematic plan view showing the external configuration of a semiconductor device according to the fourth embodiment of this technology.

[0085] The semiconductor device 1D according to the fourth embodiment of this technology has basically the same configuration as the semiconductor device 1A according to the first embodiment described above, but differs in the following configuration.

[0086] Specifically, as shown in Figure 14, in this fourth embodiment of the semiconductor device 1D, one end of the external connection terminals 58 (6P, 6N, 8U, 8V, 8W) is bent inward into the frame 5. In this configuration, one end of the external connection terminals 58 crosses the boundary between the frame 5 and the lid member 40 in a plan view, so adhesive cannot be applied from the outside to the boundary 40 below the external connection terminals 58 in a plan view. For this reason, a flow passage is formed below the external connection terminals 58, connecting the recess 3 of the case member to the outside. Therefore, even in the semiconductor device 1D in which one end of the external terminals 58 is bent inward, by providing the inner lid member 51 of this technology, it is possible to suppress external leakage of oil components that have seeped from inside the sealing resin 30 to the resin surface and leak out to the outside of the semiconductor device 1C.

[0087] Although the present technology has been described in detail based on the above embodiments and their modifications, the present technology (the technology relating to this disclosure) is not limited to the above embodiments and their modifications, and can be modified in various ways without departing from its essence. [Explanation of Symbols]

[0088] 1… Semiconductor equipment 2…Case components 3…recess 4...Heat sink 5…Frame body 5c... Step section 5d...Protruding part 5e…Mounting holes 5f…part 6P... Positive terminal 6N…Negative terminal 8U, 8V, 8W… Output terminals 9... Auxiliary terminals 10…Insulated circuit board 11…Insulating board 12...Circuit Pattern 13...Metal plate 20A, 20B… Semiconductor chips 22…Wiring board 23… Semiconductor chips 30…Sealing resin 40... Lid component 50…Oil-absorbing material 51…Inner lid member 52a...First surface 52b...Second face 53…recess 55...Elastic body 56…Porous insulating material 57…Adhesive material 58…External connection terminal

Claims

1. A case member having a recess, A semiconductor chip provided in the recess of the case member, A sealing resin containing an oily component and provided covering the semiconductor chip within the recess of the case member, A lid member fixed to the case member so as to close the opening side of the recess of the case member, A semiconductor device comprising an oil absorber disposed between the sealing resin and the lid member, which absorbs oily substances seeping out from the sealing resin.

2. The semiconductor device according to claim 1, characterized in that the oil absorber is separated from the sealing resin.

3. The semiconductor device according to claim 2, wherein the separation dimension between the oil absorber and the sealing resin is 0.5 mm or more and 2.0 mm or less.

4. The semiconductor device according to claim 1, wherein the oil absorber is a plate-shaped inner lid member having a recess on the surface facing the sealing resin that is recessed in a direction away from the sealing resin.

5. The semiconductor device according to claim 4, wherein the recess of the inner cover member is separated from the outer peripheral edge of the inner cover member in a plan view.

6. The semiconductor device according to claim 4, wherein the inner lid member is supported by the lid member via an elastic body that elastically deforms due to an upward force acting on the inner lid member due to the thermal expansion of the sealing resin.

7. The semiconductor device according to claim 1, wherein the oil absorber is a plate-shaped porous insulating member having voids inside.

8. The semiconductor device according to claim 7, wherein the porous insulating member is an elastic body that elastically deforms due to the upward force acting on the porous insulating member due to the thermal expansion of the sealing resin.

9. The case member includes a heat sink and a frame fixed to the heat sink and surrounding the semiconductor chip. The semiconductor device according to claim 1, wherein the frame is provided with external terminals that extend both inside and outside the frame.

10. The semiconductor device according to claim 9, wherein the external terminal is electrically connected to the semiconductor chip via a connecting member.

11. The semiconductor device according to claim 1, further comprising an insulating circuit board provided in the recess of the case member and on which the semiconductor chip is mounted.

12. The semiconductor device according to claim 1, characterized in that the sealing resin is a silicone gel containing a liquid low molecular weight siloxane as the oily component.

Images