Semiconductor device and method of manufacturing semiconductor device

Abstract

In a semiconductor device, a first lead frame (310) and a second lead frame (320) are fixed to a metal conductor base (100) by an organic insulating film (600) made of a polyimide-based material. The organic insulating film satisfies the following relationship: t press1 > t cast1 > t press2 > t cast1 where t press1 is the thickness of a portion of the organic insulating film sandwiched between the metal conductor base and the first lead frame, t press2 is the thickness of a portion of the organic insulating film sandwiched between the metal conductor base and the second lead frame, and t cast1 is the thickness of a portion of the organic insulating film not sandwiched between the metal conductor base and the first lead frame and not sandwiched between the metal conductor base and the second lead frame.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a semiconductor device and a manufacturing method of a semiconductor device. BACKGROUND

[0002] Conventionally, a power module as a power converter is known. US2013 / 0307156 A1 proposes a power module in which semiconductor devices are disposed between two insulating substrates. The two insulating substrates have wiring patterns formed on front and rear surfaces. The wiring patterns formed on the opposite surfaces of the two insulating substrates are electrically connected by a metal via in the space between the two insulating substrates.

[0003] WO2015 / 025582 A proposes a power module equipped with a pair of heat dissipation bases. Between the pair of heat dissipation bases, two semiconductor devices electrically connected in series are sandwiched between conductor plates. The size of the surface of the heat dissipation base facing the conductor plate is larger than the size of the surface of the conductor plate facing the heat dissipation base. The conductor plates are connected to the wiring formed with terminals. The conductor plates, the wiring, and the terminals are pre-processed into desired shapes.

[0004] The semiconductor devices and the conductor plates are first sealed with resin so that the conductor plate surface opposite to the semiconductor devices is exposed. The pair of heat dissipation bases is secondarily sealed with resin so that the heat dissipation base surface opposite to the conductor plates is exposed.

[0005] In the above configuration, the heat dissipation bases and the conductor plates are insulated by an insulating sheet. The insulating sheet is thermally compression-bonded to the conductor plates that are first sealed. Subsequently, the insulating sheet and the heat dissipation bases are thermally compression-bonded. Thereafter, the secondary sealing is performed. As a result, the insulating sheet is sandwiched between the heat dissipation bases and the conductor plates.

[0006] In WO2015 / 025582 A, the conductor plates, the wiring, and the terminals are pre-processed. On the other hand, JP2017-205948 A proposes a technology capable of processing a metal plate into a desired pattern after thermal compression-bonding.

[0007] Specifically, two laminated plates in which an adhesive sheet as an insulating sheet is attached to a metal foil are prepared, and the adhesive sheets of the two laminated plates are thermally compression-bonded to each other to form a laminated plate having metal foils on both sides. Then, by processing the metal foils, a desired pattern can be formed on the metal foils. SUMMARY

[0008] At present, a power module operates in a state in which it is mounted to a device that requires power conversion. Therefore, the device requires a space for mounting the power module in a housing of the device. In addition, the power module needs to have a size capable of mounting the power module in a housing of the power module. Therefore, it is desirable to reduce the size of the power module.

[0009] However, in the power module shown in US2013 / 0307156A1, the through hole electrically connects between the wiring patterns of the two insulating substrates. Therefore, not only the area of the semiconductor device but also the connection area of the through hole on the front surface and the rear surface of the insulating substrate needs to be secured. Thus, it is difficult to reduce the size of the front surface and the rear surface of the insulating substrate in the planar direction.

[0010] Further, in order to reduce the size, it is necessary to integrate a plurality of semiconductor devices into one power module. However, in US2013 / 0307156A1, as the wiring pattern is formed on the front surface and the rear surface of each insulating substrate, the wiring pattern becomes complicated as the plurality of semiconductor devices are integrated. As a result, each insulating substrate can be warped due to the difference between the linear expansion coefficient of the wiring pattern and the linear expansion coefficient of each insulating substrate. Further, each insulating substrate can be warped due to the difference in the density of the wiring pattern formed on the front surface and the rear surface of each insulating substrate. Thus, it is difficult to integrate a plurality of semiconductor devices into one power module.

[0011] On the other hand, in the power module shown in WO2015 / 025582 A, it is possible to integrate two semiconductor devices. However, the size of the surface of the heat sink facing the conductor plate is different from the size of the surface of the conductor plate facing the heat sink. Since the portion of the insulating sheet that is not sandwiched between the heat sink and the conductor plate is not subjected to pressure during the thermal compression bonding process, the portion that is not sandwiched in the middle can not be bonded. Then, since the portion that is not sandwiched in the middle is not pressed from the conductor plate, the portion can deteriorate with aging to become a starting point of peeling from the insulating sheet.

[0012] Further, since the portion of the insulating sheet that is not sandwiched between the heat sink and the conductor plate is not constrained by the conductor plate, the portion can be thicker than the portion that is sandwiched between the heat sink and the conductor plate. Thus, the bonding force caused by the resin sealing is difficult to act on the portion of the insulating sheet that is not sandwiched between the heat sink and the conductor plate, making the portion that is not sandwiched in the middle easy to peel off from the heat sink. Thus, although it is possible to integrate two semiconductor devices, it is difficult to ensure the reliability of the power module.

[0013] On the other hand, in the laminated substrate shown in JP2017-205948 A, the metal foil pattern can be formed by machining or etching the metal foil. Thus, compared to the case where a metal member such as a pre-patterned conductor plate is used, it is possible to reduce the size in the planar direction. However, when the metal foil is thick, it can take a long time to form the pattern if machining is performed only by the etching process. Further, the corners of the pattern opening can be rounded by long-time etching.

[0014] Accordingly, it is conceivable to pattern the metal foil by machining. However, since it is difficult to completely remove the metal foil by machining alone, it is necessary to perform an etching process after machining. Thus, the cost of patterning is high. Accordingly, it is difficult to reduce the size without increasing the cost.

[0015] Since a portion of the adhesive sheet is exposed from the metal foil by the patterning of the metal foil, the adhesive sheet can have an unbound portion that is not sandwiched between the two metal foils. Thus, similarly to the above, the portion of the adhesive sheet that is not sandwiched between the two metal foils is easily peeled off from the metal foil.

[0016] In view of the above problems, a first object of the present disclosure is to provide a semiconductor device capable of integrating a plurality of power elements to reduce the size, ensure reliability by suppressing peeling of an insulating film, and reduce the cost. A second object of the present disclosure is to provide a manufacturing method of a semiconductor device.

[0017] The semiconductor device according to the first aspect of the present disclosure includes a metal conductor base, a first lead frame, a second lead frame, a third lead frame, and a fourth lead frame. Further, the semiconductor device includes a tab portion, a first power element, a second power element, and a molded resin portion.

[0018] The metal conductor base has a first surface and a second surface located on the opposite side of the first surface. The first lead frame is fixed to the first surface of the metal conductor base. The second lead frame is fixed to the first surface of the metal conductor base and is disposed away from the first lead frame. The third lead frame is disposed above the first lead frame in a thickness direction perpendicular to the first surface of the metal conductor base. The fourth lead frame is disposed above the second lead frame in the thickness direction.

[0019] The tab portion has a first end portion and a second end portion located on the opposite side of the first end portion. The first end portion is integrally formed with the first lead frame. The second end portion is integrally formed with the fourth lead frame. The tab portion electrically connects the first lead frame and the fourth lead frame.

[0020] The first power element is disposed between the first lead frame and the third lead frame. The first power element is electrically connected to the first lead frame and the third lead frame. The second power element is disposed between the second lead frame and the fourth lead frame. The second power element is electrically connected to the second lead frame and the fourth lead frame.

[0021] The molded resin portion integrally seals a portion of the metal conductor base, the first lead frame, the second lead frame, the first power element, the second power element, the tab portion, the third lead frame, and the fourth lead frame, in a state in which the second surface of the metal conductor base is exposed from the molded resin portion.

[0022] The first lead frame is fixed to the first surface of the metal conductor base and the second lead frame is fixed to the first surface of the metal conductor base by the organic insulating film made of a polyimide-based material.

[0023] The organic insulating film satisfies the following relationship: t press1 > t cast1 > t press2 > t cast1 where t press1 is a thickness of a portion of the organic insulating film interposed between the metal conductor base and the first lead frame, t press2 is a thickness of a portion of the organic insulating film interposed between the metal conductor base and the second lead frame, and t cast1 is a thickness of a portion of the organic insulating film not interposed between the metal conductor base and the first lead frame and not interposed between the metal conductor base and the second lead frame.

[0024] In the method of manufacturing a semiconductor device according to the second aspect of the present disclosure, a metal conductor base, a first lead frame, and a second lead frame are prepared. The metal conductor base has a first surface and a second surface located on an opposite side of the first surface.

[0025] Subsequently, the first surface of the metal conductor base is coated with a base-side film made of a polyimide-based resin, a mounting surface of the first lead frame mounted to the first surface of the metal conductor base is coated with a first film made of a polyimide-based resin, and a mounting surface of the second lead frame mounted to the first surface of the metal conductor base is coated with a second film made of a polyimide-based resin.

[0026] Next, the base-side film, the first film, and the second film are dried so that the base-side film, the first film, and the second film are semi-cured.

[0027] Next, the base-side film is bonded together with the first film, and the base-side film is bonded together with the second film.

[0028] Subsequently, the base-side film, the first film, and the second film are cured to form an organic insulating film.

[0029] After that, a third lead frame is provided above the first lead frame in a thickness direction perpendicular to the first surface of the metal conductor base, a fourth lead frame is provided above the second lead frame in the thickness direction, and the first lead frame and the fourth lead frame are electrically connected by a joint portion.

[0030] The curing of the base-side film, the first film, and the second film includes forming the organic insulating film to satisfy the following relationship: t press1 > t cast1 > t press2 > t cast1 where t press1is a thickness of a portion where the organic insulating film is sandwiched between the metal conductor base and the first lead frame, t press2 is a thickness of a portion where the organic insulating film is sandwiched between the metal conductor base and the second lead frame, and t cast1 is a thickness of a portion where the organic insulating film is not sandwiched between the metal conductor base and the first lead frame and is not sandwiched between the metal conductor base and the second lead frame.

[0031] Therefore, the first lead frame and the fourth lead frame, which are different in position in the thickness direction and in a disposition direction in which the first lead frame and the second lead frame are disposed within a planar direction parallel to the first surface of the metal conductor base, are connected by the joint portion. As a result, the first lead frame and the fourth lead frame can be electrically connected at the shortest distance. Therefore, integration of a plurality of power elements in the disposition direction can reduce the size of the semiconductor device.

[0032] Further, the first lead frame, the second lead frame, and the metal conductor base are fixed by the organic insulating film made of a polyimide-based material. Therefore, it is not necessary to perform machining such as machining or etching on a metal plate that is a source of the first lead frame and the second lead frame. Therefore, it is possible to reduce the cost of the semiconductor device.

[0033] Further, the thickness of the portion of the organic insulating film that is not sandwiched between the first lead frame and the second lead frame is thinner than the thickness of the portion that is sandwiched between the first lead frame and the second lead frame. Therefore, the bonding force of the molded resin easily acts on the portion of the organic insulating film that is not sandwiched between the first lead frame and the second lead frame, and thus it is possible to suppress peeling of the portion. Therefore, it is possible to ensure the reliability of the semiconductor device. BRIEF DESCRIPTION OF DRAWINGS

[0034] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0035] Figure 1 is a perspective view of a semiconductor device according to a first embodiment;

[0036] Figure 2 is a cross-sectional view of the semiconductor device taken along line II-II in Figure 1

[0037] Figure 3 is a cross-sectional view of the semiconductor device taken along line III-III in Figure 1

[0038] Figure 4 is a cross-sectional view of the semiconductor device taken along line IV-IV in Figure 1

[0039] Figure 5 ​​​is a perspective view of the first metal conductor base, the first lead frame, the second lead frame, the fifth lead frame, and the seventh lead frame;

[0040] Figure 6 is a view of a side surface of the first lead frame and a side surface of the second lead frame;

[0041] Figure 7 is a plan view showing the third lead frame, the first wiring terminal, and the second wiring terminal;

[0042] Figure 8 is an enlarged sectional view showing the first organic insulating film;

[0043] Figure 9 is an enlarged sectional view showing the second organic insulating film;

[0044] Figure 10 is a view showing a manufacturing process of a semiconductor device;

[0045] Figure 11A and Figure 11B is a view showing a coating process;

[0046] Figure 12A and Figure 12B is a view showing a coating process;

[0047] Figure 13 is an explanatory view of a dry molding process;

[0048] Figure 14 is a view showing formation of a polyamic acid as a precursor of a polyimide;

[0049] Figure 15A and Figure 15B is a view showing a bonding process;

[0050] Figure 16 is a view showing formation of a polyimide film;

[0051] Figure 17 is a view showing a portion to which a pressing pressure is not applied in a full curing process;

[0052] Figure 18 is a view showing a relationship between a pressing pressure and a shear strength;

[0053] Figure 19 is a view showing a pressurized portion and a non-pressurized portion in a case where a pressing pressure is applied in a full curing process;

[0054] Figure 20 is a view showing warping of a substrate when a temperature stress is generated;

[0055] Figure 21 is a view showing mechanical properties of a substrate material;

[0056] Figure 22 This is a graph showing the relationship between the front-to-back volume ratio and warpage of the substrate; and

[0057] Figure 23 This is a graph showing the relationship between the drying temperature and shear strength of each film in the dry forming process of the second embodiment. Detailed Implementation

[0058] Embodiments of this disclosure will now be described with reference to the accompanying drawings. In the following embodiments, the same or equivalent elements are represented by the same reference numerals in the drawings.

[0059] (First Embodiment)

[0060] The first embodiment will be described with reference to the accompanying drawings. The semiconductor device according to this embodiment can be applied to power converters such as inverters.

[0061] like Figures 1 to 8 As shown, the semiconductor device 1 includes a first metal conductor base 100, a second metal conductor base 200, first to eighth lead frames 310 to 380, and first to third connector portions 410 to 430. The semiconductor device 1 also includes first to sixth power elements 510 to 560, a first organic insulating film 600, a second organic insulating film 700, and a molding resin portion 800.

[0062] like Figure 2 As shown, the first metal conductor base 100 has a first surface 101 and a second surface 102 located opposite to the first surface 101. The second metal conductor base 200 has a first surface 201 and a second surface 202 located opposite to the first surface 201. The metal conductor bases 100 and 200 receive heat from the lead frames 310 to 340 and release the heat to the outside. The metal conductor bases 100 and 200 are metal plates made of, for example, Cu.

[0063] Lead frames 310 to 340 are heat sinks that receive heat from power elements 510 and 520 and release heat to metal conductor bases 100 and 200. Furthermore, lead frames 310 to 340 are wiring for supplying electrical power to power elements 510 and 520. Lead frames 310 to 340 are metal blocks made of, for example, Cu.

[0064] The first lead frame 310 is fixed to the first surface 101 of the first metal conductor base 100 by a first organic insulating film 600 made of polyimide-based material. The second lead frame 320 is fixed to the first surface 101 of the first metal conductor base 100 by the first organic insulating film 600 and is disposed away from the first lead frame 310.

[0065] The first lead frame 310 and the second lead frame 320 are disposed along a disposition direction which is one of the planar directions parallel to the first surface 101 of the first metal conductor base 100.

[0066] The third lead frame 330 is disposed above the first lead frame 310 in a thickness direction perpendicular to the first surface 101 of the first metal conductor base 100. The third lead frame 330 is paired with the first lead frame 310. The third lead frame 330 is fixed to the first surface 201 of the second metal conductor base 200 by the second organic insulating film 700 made of a polyimide-based material.

[0067] The fourth lead frame 340 is disposed above the second lead frame 320 in the thickness direction. The fourth lead frame 340 is paired with the second lead frame 320. The fourth lead frame 340 is fixed to the first surface 201 of the second metal conductor base 200 by the second organic insulating film 700. The fourth lead frame 340 is disposed away from the third lead frame 330.

[0068] The first joint portion 410 is a wiring electrically connecting the first lead frame 310 and the fourth lead frame 340. The first joint portion 410 has a first end portion 411 and a second end portion 412 located on the opposite side of the first end portion 411. The first end portion 411 is integrally formed with the first lead frame 310. The second end portion 412 is integrally formed with the fourth lead frame 340. The first joint portion 410 passes through a space between the first lead frame 310 and the fourth lead frame 340 along the disposition direction and the thickness direction. As a result, the first lead frame 310 and the fourth lead frame 340 can be connected at the shortest distance.

[0069] The first power element 510 and the second power element 520 are semiconductor chips on which semiconductor elements such as IGBTs, power MOS transistors, and the like are formed. The first power element 510 has a first signal terminal 511. The first signal terminal 511 is electrically connected to a pad of the semiconductor chip. The second power element 520 has a second signal terminal 521. The second signal terminal 521 is electrically connected to a pad of the semiconductor chip. The first signal terminal 511 and the second signal terminal 521 receive a control signal from an external device.

[0070] The first power element 510 is disposed between the first lead frame 310 and the third lead frame 330. The first power element 510 is electrically and thermally connected to the first lead frame 310 via a solder 512. Above the first power element 510, a heat sink 514 made of, for example, Cu is electrically and thermally connected via a solder 513. The heat sink 514 is electrically and thermally connected to the third lead frame 330 via a solder 515.

[0071] The second power element 520 is provided between the second lead frame 320 and the fourth lead frame 340. The second power element 520 is electrically and thermally connected to the second lead frame 320 via the solder 522. Above the second power element 520, a heat sink 524 made of, for example, Cu is electrically and thermally connected via the solder 523. The heat sink 524 is electrically and thermally connected to the fourth lead frame 340 via the solder 525.

[0072] In the present embodiment, the semiconductor device 1 includes three groups composed of the lead frames 310 to 340, the first terminal portion 410, the first power element 510, and the second power element 520 as shown in FIG. 4. The three groups are provided in a direction perpendicular to the direction of provision on the first surface 101 of the first metal conductor base 100. As shown in FIG. 4, the three second lead frames 320 in the three groups are integrally formed as one lead frame. Similarly, the three third lead frames 330 in the three groups are integrally formed as one lead frame. Figure 2 Figure 5

[0073] Figure 3 A group composed of the lead frames 320, 330, 350, 360, the second terminal portion 420, the third power element 530, and the fourth power element 540 is shown. Figure 4 A group composed of the lead frames 320, 330, 370, 380, the third terminal portion 430, the fifth power element 550, and the sixth power element 560 is shown. The fifth lead frame 350 and the seventh lead frame 370 correspond to the above-described first lead frame 310. The sixth lead frame 360 and the eighth lead frame 380 correspond to the above-described fourth lead frame 340. The second terminal portion 420 and the third terminal portion 430 correspond to the above-described first terminal portion 410. The third power element 530 and the fifth power element 550 correspond to the above-described first power element 510. The fourth power element 540 and the sixth power element 560 correspond to the above-described second power element 520.

[0074] The third power element 530 is connected to a heat sink 531. The third power element 530 has a third signal terminal 532. The fourth power element 540 is connected to a heat sink 541. The fourth power element 540 has a fourth signal terminal 542. The fifth power element 550 is connected to a heat sink 551. The fifth power element 550 has a fifth signal terminal 552. The sixth power element 560 is connected to a heat sink 561. The sixth power element 560 has a sixth signal terminal 562.

[0075] ​​That is, in the semiconductor device 1, six power elements 510 to 560 are packaged as one. According to the above-described structure, the first power element 510 and the second power element 520 are connected in series. The third power element 530 and the fourth power element 540 are connected in series. The fifth power element 550 and the sixth power element 560 are connected in series. Each of the power elements 520, 540, and 560 forms, for example, an upper arm, and each of the power elements 510, 530, and 550 forms, for example, a lower arm. Then, each of intermediate potentials between the upper arms and the lower arms is outputted to the outside via the first output terminal 570, the second output terminal 571, or the third output terminal 572. Figure 1 The first output terminal 570, the second output terminal 571, or the third output terminal 572 outputs to the outside as shown.

[0076] As shown in FIG. 1, the first lead frame 310 is provided with two first wiring terminals 311. Each of the first wiring terminals 311 has a first connecting portion 312 and a first front end portion 313 located on the opposite side of the first connecting portion 312. Figure 5 The first connecting portion 312 of one of the first wiring terminals 311 is located above the portion between the first lead frame 310 and the fifth lead frame 350 and is formed integrally with the second lead frame 320. The first front end portion 313 of one of the first wiring terminals 311 is disposed on the opposite side of the second lead frame 320 with respect to the first lead frame 310 and the fifth lead frame 350 in the arrangement direction.

[0077] As shown in FIG. 2, the first connecting portion 312 of one of the first wiring terminals 311 is bent in the thickness direction. As a result, a part of the intermediate portion between the first connecting portion 312 and the first front end portion 313 of one of the first wiring terminals 311 is disposed between the lead frames 310, 330, and 350 without contacting the lead frames 310, 330, 350, and the power elements 510, 530.

[0078] Figure 6 The first connecting portion 312 of the other first wiring terminal 311 is located above the portion between the fifth lead frame 350 and the seventh lead frame 370 and is formed integrally with the second lead frame 320. The first front end portion 313 of the other first wiring terminal 311 is disposed on the opposite side of the second lead frame 320 with respect to the fifth lead frame 350 and the seventh lead frame 370 in the arrangement direction.

[0079] The first connecting portion 312 of the other first wiring terminal 311 is bent in the thickness direction. As a result, a part of the intermediate portion between the first connecting portion 312 and the first front end portion 313 of the other first wiring terminal 311 is disposed between the lead frames 330, 350, and 370 without contacting the lead frames 330, 350, 370, and the power elements 530, 550.

[0080] As shown in FIG. 3, the first connecting portion 312 of one of the first wiring terminals 311 is bent in the thickness direction. As a result, a part of the intermediate portion between the first connecting portion 312 and the first front end portion 313 of one of the first wiring terminals 311 is disposed between the lead frames 310, 330, and 350 without contacting the lead frames 310, 330, 350, and the power elements 510, 530.

[0081] As shown in FIG. 3, the first connecting portion 312 of one of the first wiring terminals 311 is bent in the thickness direction. As a result, a part of the intermediate portion between the first connecting portion 312 and the first front end portion 313 of one of the first wiring terminals 311 is disposed between the lead frames 310, 330, and 350 without contacting the lead frames 310, 330, 350, and the power elements 510, 530.​Figure 7 As shown, the third lead frame 330 includes two second wiring terminals 331. Each of the second wiring terminals 331 has a second connecting portion 332 and a second front end portion 333 located on the opposite side of the second connecting portion 332.

[0082] The second connecting portion 332 of one of the second wiring terminals 331 is integrally formed with the corresponding portion of the third lead frame 330 located between the fourth lead frame 340 and the sixth lead frame 360. The second front end portion 333 of the one of the second wiring terminals 331 is disposed on the opposite side of the fourth lead frame 340 with respect to the third lead frame 330 in the disposing direction. A portion of the intermediate portion between the second connecting portion 332 and the second front end portion 333 of the one of the second wiring terminals 331 does not contact the first power element 510 and the second power element 520.

[0083] The second connecting portion 332 of the other of the second wiring terminals 331 is integrally formed with the corresponding portion of the third lead frame 330 located between the sixth lead frame 360 and the eighth lead frame 380. The second front end portion 333 of the other of the second wiring terminals 331 is disposed on the opposite side of the fourth lead frame 340 with respect to the third lead frame 330 in the disposing direction. A portion of the intermediate portion between the second connecting portion 332 and the second front end portion 333 of the other of the second wiring terminals 331 does not contact the third power element 530 and the fifth power element 550.

[0084] The first wiring terminals 321 and the second wiring terminals 331 are terminals for supplying power to the power elements 510 to 560. One of the first wiring terminals 321 and one of the second wiring terminals 331 are power supply terminals of the power elements 510 to 560, and the others are ground terminals.

[0085] The molded resin portion 800 integrally seals a portion of the metal conductor bases 100 and 200, the lead frames 310 to 380, the power elements 510 to 560, and the joint portions 410 to 430, and the second surfaces 102 and 202 of the metal conductor bases 100 and 200 are exposed. In addition, the molded resin portion 800 seals the first wiring terminals 321 and the second wiring terminals 331 in a state in which the first front end portions 323 of the first wiring terminals 321 and the second front end portions 333 of the second wiring terminals 331 are exposed from the molded resin portion 800. The molded resin portion 800 is made of a thermosetting resin such as an epoxy resin. The term "exposed from" means "not covered by".

[0086] The first organic insulating film 600 fixes the first surface 101 of the first metal conductor base 100 and each of the lead frames 310, 320, 350, and 370. The first organic insulating film 600 thermally connects the first surface 101 of the first metal conductor base 100 and each of the lead frames 310, 320, 350, and 370 while electrically insulating the first surface 101 of the first metal conductor base 100 and each of the lead frames 310, 320, 350, and 370.

[0087] As shown in FIG. 6, the first organic insulating film 600 has a first base side film 610, a first film 620, and a second film 630. The first base side film 610 is formed on the entire first surface 101 of the first metal conductor base 100. The first film 620 is formed on the entire mounting surface 311, 351, and 371 of the lead frames 310, 350, and 370 mounted to the first surface 101 of the first metal conductor base 100. The second film 630 is formed on the entire mounting surface 324 of the second lead frame 320 mounted to the first surface 101 of the first metal conductor base 100. The surface layer portion of the first film 620 and the surface layer portion of the second film 630 are chemically bonded to the surface layer portion of the first base side film 610 by forming a polymer. Figure 8 The first organic insulating film 600 satisfies the following relationships: t press1 > t cast1 > t press2 > t cast1 > t press1 , where t press2 is the thickness of the portion of the first organic insulating film 600 sandwiched between the first metal conductor base 100 and the first lead frame 310, t cast1 is the thickness of the portion of the first organic insulating film 600 sandwiched between the first metal conductor base 100 and the second lead frame 320, and t press1 is the thickness of the portion of the first organic insulating film 600 not sandwiched between the first metal conductor base 100 and the first lead frame 310 and not sandwiched between the first metal conductor base 100 and the second lead frame 320.

[0088] The thickness t press1 of the first organic insulating film 600 corresponds to the thickness of the portion of the first organic insulating film 600 sandwiched between the first metal conductor base 100 and the fifth lead frame 350, and the thickness of the portion of the first organic insulating film 600 sandwiched between the first metal conductor base 100 and the seventh lead frame 370. Therefore, the above relationships are also satisfied for the fifth lead frame 350 and the seventh lead frame 370.

[0089]

[0090] The second organic insulating film 700 fixes the first surface 201 of the second metal conductor base 200 and each of the lead frames 330, 340, 360, and 380. The second organic insulating film 700 thermally connects the first surface 201 of the second metal conductor base 200 and each of the lead frames 330, 340, 360, and 380 while electrically insulating the first surface 201 of the second metal conductor base 200 and each of the lead frames 330, 340, 360, and 380.

[0091] As shown in FIG. 7, the second organic insulating film 700 has a second base side film 710, a third film 720, and a fourth film 730. The second base side film 710 is formed on the entire first surface 201 of the second metal conductor base 200. The third film 720 is formed on the entire mounting surface 334 of the third lead frame 330 mounted to the first surface 201 of the second metal conductor base 200. The fourth film 730 is formed on the entire mounting surfaces 341, 361, and 381 of the lead frames 340, 360, and 380 mounted to the first surface 201 of the second metal conductor base 200. A surface layer portion of the third film 720 and a surface layer portion of the fourth film 730 are chemically bonded with a surface layer portion of the second base side film 710 by forming a polymer. Figure 9

[0092] The second organic insulating film 700 satisfies the following relationships: t press3 > t cast2 > t press4 > t cast2 > t press3 , where t press4 is a thickness of a portion of the second organic insulating film 700 sandwiched between the second metal conductor base 200 and the fourth lead frame 340, and t cast2 is a thickness of a portion of the second organic insulating film 700 not sandwiched between the second metal conductor base 200 and the third lead frame 330 and not sandwiched between the second metal conductor base 200 and the fourth lead frame 340.

[0093] The thickness t press4 also corresponds to a thickness of a portion of the second organic insulating film 700 sandwiched between the second metal conductor base 200 and the sixth lead frame 360, and a thickness of a portion of the second organic insulating film 700 sandwiched between the second metal conductor base 200 and the eighth lead frame 380. Therefore, the above relationships are also satisfied for the sixth lead frame 360 and the eighth lead frame 380.

[0094] In the organic insulating films 600 and 700, the thicknesses t cast1 and t cast2 ​The portions that contact the molding resin portion 800 are the parts where the molding resin portion 800 is located; therefore, the bonding force exerted by the molding resin portion 800 on these portions increases as the thickness of these portions decreases. Furthermore, due to the thickness t in the organic insulating films 600 and 700... press1 t press2 t press3 and t press4 The parts are insulation protection parts, therefore the bonding force of the molding resin part 800 on these parts increases as the thickness of these parts decreases. Therefore, it is unlikely that the organic insulating films 600 and 700 will peel off from the metal conductor bases 100 and 200.

[0095] Thickness t press1 t press2 t press3 and t press4 For example, it ranges from 5 micrometers to 50 micrometers. Thickness t cast1 and t cast2 For example, the size ranges from 10 micrometers to 100 micrometers. Organic insulating films 600 and 700 are formed using the AFCAST method (a surface alignment and curing method for solvent-cast films).

[0096] The sum of the areas of the mounting surfaces 311, 351, and 371 of the first surface 101 of the first metal conductor base 100 for the lead frames 310, 350, and 370 is defined as the first area. The area of ​​the mounting surface 324 of the second lead frame 320 for the first surface 101 of the first metal conductor base 100 is defined as the second area.

[0097] like Figure 5 As shown, the area of ​​the first surface 101 of the first metal conductor base 100 is greater than the sum of the first area and the second area. Further, the first lead frame 310 and the second lead frame 320 are disposed inside the outer edge 103 of the first surface 101 of the first metal conductor base 100.

[0098] Accordingly, since each lead frame 310, 320, 350, and 370 is surrounded by a first organic insulating film 600, which serves as an insulator, the insulation characteristics of each lead frame 310, 320, 350, and 370 can be ensured. The area of ​​the second surface 201 of the second metal conductor base 200 also satisfies the above-described relationship with the areas of the lead frames 330, 340, 360, and 380. The above describes the overall structure of the semiconductor device 1 according to this embodiment.

[0099] Next, a method for manufacturing semiconductor device 1 will be described. In this embodiment, metal conductor substrates 100 and 200 and lead frames 310 to 380 are bonded together using the AFCAST method. Specifically, as Figure 10As shown, the preparation process of the copper plate, the coating process, the dry molding process, the bonding process, and the full curing process are sequentially performed.

[0100] First, in the preparation process, the metal conductor bases 100, 200, and the lead frames 310 to 380 are prepared by subjecting the copper plate to press working. For example, the first joint portion 410 is integrally formed with the first lead frame 310 during the press working. The same applies to the second joint portion 420 and the third joint portion 430. In addition, each first wiring terminal 321 is integrally formed with the second lead frame 320. Each second wiring terminal 331 is integrally formed with the third lead frame 330.

[0101] Subsequently, in the coating process, as shown in Figure 11A and 11B the first surface 101 of the first metal conductor base 100 is coated with a first base-side film 610 made of a polyimide-based resin, which is an insulating material. As shown in Figure 12A and 12B the mounting surfaces 311, 351, and 371 of the lead frames 310, 350, and 370 are coated with a first film 620 made of a polyimide-based resin. The mounting surface 324 of the second lead frame 320 is coated with a second film 630 made of a polyimide-based resin.

[0102] The polyimide-based resin is obtained by dissolving a polyamic acid, which is obtained by polymerizing an acid anhydride and a diamine in a predetermined molar ratio, in an organic solvent such as N,N-dimethylacetamide or N-methylpyrrolidone (NMP). The acid anhydride includes, for example, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, hydroxydiphthalic dianhydride, ethylene glycol distilbene dianhydride, and the like. The diamine includes oxydianiline, phenylenediamine, polytetramethylene oxide di-p-aminobenzoate, and the like. As the polyimide-based resin, a polyamide-imide having an amide bond introduced into a polyimide chain, a polyimide-siloxane having a polysiloxane structure, or the like can be used.

[0103] As the coating method, a solution casting method, an extrusion method, an imprint transfer method, a spray coating method, a casting and spin coating method, or the like can be employed. As described above, in the coating process, a solution containing a solvent is applied as the first base-side film 610, the first film 620, and the second film 630.

[0104] The second surface 201 of the second metal conductor base 200 and the lead frames 330, 340, 360, and 380 are also coated with a polyimide-based resin film in the same manner as described above, respectively.

[0105] After the coating process, in a dry molding process, the first base side film 610, the first film 620, and the second film 630 are dried so that the first base side film 610, the first film 620, and the second film 630 are semi-cured. In the present embodiment, the first base side film 610, the first film 620, and the second film 630 are semi-cured under conditions of 0.01 P VP <P<P VP and T ≥ 100 °C.

[0106] Further, P VP = 10 (9.368-3477 / (273.15+T)) where T is the temperature of NMP when NMP is used as a solvent, P VP is the vapor pressure of NMP with respect to the temperature T. The vapor pressure is the pressure at the time of evaporation of the solvent. P VP is an approximate expression calculated through experiments. Figure 13 An example of P VP obtained from the approximate expression is shown. P is the vacuum pressure value of a chamber in which the first base side film 610, the first film 620, and the second film 630 are provided inside. When the polyimide-based resin is dried for a certain time under the above conditions, NMP as a solvent can evaporate without completely curing the polyimide-based resin. As shown in Figure 14 polyamide acid as a polyimide precursor is generated.

[0107] The second base side film 710, the third film 720, and the fourth film 730 are also semi-cured according to the above conditions.

[0108] In the bonding process, the first base side film 610 is bonded together with the first film 620, and the first base side film 610 is bonded together with the second film 630. At the time of bonding, the monomer surfaces in the semi-cured state are brought into contact with each other.

[0109] The lead frames 310, 350, and 370 are respectively provided with the tab portions 410 to 430. Therefore, as shown in Figure 15A and 15B to avoid mechanical interference, the lead frames 310, 350, and 370 are first mounted to the first metal conductor base 100, and then the second lead frame 320 is mounted to the first metal conductor base 100.

[0110] The second metal conductor base 200 and the lead frames 330, 340, 360, and 380 are also bonded in the same manner as described above.

[0111] After that, in a full curing process, the first organic insulating film 600 is formed by curing the first base side film 610, the first film 620, and the second film 630. As shown in Figure 16As shown, a polyimide film is formed by heating polyamic acid at, for example, 200°C or higher, or by dehydrating and cyclizing polyamic acid with a catalyst. The polyimide film becomes an organic insulating film 600, 700.

[0112] In this embodiment, the first base-side film 610, the first film 620, and the second film 630 are cured while a pressing pressure is applied to the first metal conductor base 100 and the lead frames 310, 320, 350, and 370. Figure 17 As shown, considering the connector portions 410 to 430 and the first wiring terminal 321, pressing pressure is applied to the portion excluding the shaded portion.

[0113] Here, the first base-side film 610, the first film 620, and the second film 630 are cured under a pressing pressure exceeding 5 MPa between the first metal conductor base 100 and each lead frame 310, 320, 350, and 370. The surfaces of the first base-side film 610, the first film 620, and the second film 630 are not entirely uneven. However, the effect of surface roughness can be reduced by curing the first base-side film 610, the first film 620, and the second film 630 while applying the pressing pressure.

[0114] The inventors investigated the shear strength under varying pressing pressure. Shear strength is the strength of the force exerted by the lead frames 310, 320, 350, and 370 sliding on the first metal conductor base 100 when forces are applied to them. The results are as follows... Figure 16 As shown. Figure 18 As shown, sufficient shear strength was obtained when the pressing pressure was in the range of 5 MPa to 10 MPa. Therefore, it is desirable to apply a pressing pressure exceeding 5 MPa.

[0115] like Figure 19 As shown, during the complete curing process, pressing pressure is applied to the portion of the first base-side film 610 sandwiched between the first metal conductor base 100 and the lead frames 310, 320, 350, and 370. Conversely, no pressing pressure is applied to the portion of the first base-side film 610 not sandwiched between the first metal conductor base 100 and the lead frames 310, 320, 350, and 370. Therefore, a uniform pressure is applied to the portion not sandwiched in the middle using a clamp. That is, the load is applied to the center of gravity of the clamp.

[0116] Then, in the complete curing process, the first organic insulating film 600 is formed such that the thickness 600 of the first organic insulating film satisfies the following relationship: t press1 >t cast1 And t press2 >t cast1 .

[0117] The film between the second metal conductor base 200 and the lead frames 330, 340, 360, and 380 also undergoes a complete curing process in the same manner as described above to form a second organic insulating film 700 that meets the thickness requirements. As a method to reduce pressing pressure, thermoplastic resin can be used as the organic insulating films 600 and 700.

[0118] After the complete curing process, a mounting process is performed to install power components 510 to 560. Power components 510, 530, and 550 are mounted to lead frames 310, 350, and 370, respectively, and power components 520, 540, and 560 are mounted to a second lead frame 320. Furthermore, signal terminals 511, 521, 532, 542, 552, and 562 are mounted to power components 510 to 560, and heat sinks 514, 524, 531, 541, 551, and 561 are mounted above power components 510 to 560. Additionally, output terminals 570 to 572 are fabricated and connected to power components 510 to 560.

[0119] Next, the connection process is performed. In the thickness direction, lead frames 330, 340, 360, and 380 are arranged above lead frames 310, 320, 350, and 370. Then, lead frames 330, 340, 360, and 380 are joined to heat sinks 514, 524, 513, 541, 551, and 561. Furthermore, the connectors 410 to 430 of lead frames 310, 350, and 370 are electrically connected to lead frames 340, 360, and 380.

[0120] Subsequently, a molding process is performed to form the molding resin part 800. First, the aforementioned assembly is fixed onto a mold. Molten resin material is poured through the mold's gate, and the resin material solidifies to form the molding resin part 800. In this way, the semiconductor device 1 is manufactured.

[0121] The inventors investigated the warping of the first metal conductor base 100 in the semiconductor device 1 manufactured by the above method. For example... Figure 20 As shown, when thermal stress occurs, warping occurs due to the stress difference between the front conductor 910 and the rear conductor 920, even with the high rigidity of the insulation portion 900. The insulation portion 900 corresponds to each organic insulating film 600, 700, the front conductor 910 corresponds to each metal conductor base 100, 200, and the rear conductor 920 corresponds to each lead frame 310 to 380.

[0122] Therefore, the hardness of the first organic insulating film 600, i.e., the warping of the first metal conductor base 100 when the Young's modulus changes, was studied through simulation. Figure 21 As shown, three types of Cu, PI and SiN are used as materials for the first metal conductor substrate 100.

[0123] For Cu, the substrate thickness of the first metal conductor base 100 was changed. That is, the front-to-back volume ratio was changed. The front-to-back volume ratio was obtained by dividing the mounting-side volume by the base conductor volume when the volume of the first metal conductor base 100 was defined as the base conductor volume and the sum of the volumes of the lead frames 310, 320, 350, and 370 was defined as the mounting-side volume. The Young's modulus of the first organic insulating film 600 was changed to 4 GPa, 8 GPa, and 20 GPa. For PI and SiN, the substrate thickness values ​​were fixed. Furthermore, warpage analysis was performed under conditions without temperature characteristics. The results are shown in... Figure 22 .

[0124] like Figure 22 As shown, in the Cu-Si group, large warpage occurs in the SiN substrate. On the other hand, in the Cu-PI group, the warpage of the PI substrate is smaller. Furthermore, in the Cu-Cu group, it was found that good bonding can be achieved when the Young's modulus of the first organic insulating film 600 is less than 20 GPa and the volume ratio of the front to back volume is 7.0 or lower. Because the first organic insulating film 600 has low elasticity of 10 GPa or less, this follows the variation of the first metal conductor base 100, which has high rigidity. Therefore, even with complex metal patterns, the first metal conductor base 100 will not warp. Thus, by satisfying the above conditions, good bonding of each power element 510 to 560 via solder can be ensured.

[0125] The above relationships are the same for the second metal conductor base 200, each lead frame 330, 340, 360, 380, and the second organic insulating film 700.

[0126] As described above, lead frames 310, 350, 370 and 340, 360, 380, which are disposed at different positions in the setting direction and thickness direction, are connected by connectors 410 to 430. As a result, lead frames 310, 350, 370 and 340, 360, 380 can be electrically connected with the shortest distance. Therefore, the size of the semiconductor device 1 in which power elements 510 to 560 are integrally formed in the setting direction is reduced.

[0127] Furthermore, the metal conductor bases 100 and 200, as well as the lead frames 310 to 380, are fixed by organic insulating films 600 and 700 made of polyimide-based material. Therefore, machining and etching of the metal plates from which the lead frames 310 to 380 originate is unnecessary. Moreover, each component can be fixed using inexpensive polyimide-based material. Thus, the cost of the semiconductor device 1 can be reduced.

[0128] Further, the thickness of the portions where the organic insulating films 600 and 700 are not interposed between the metal conductor bases 100 and 200 and the lead frames 310 to 380 is thinner than the thickness of the portions where the organic insulating films 600 and 700 are interposed between the metal conductor bases 100 and 200 and the lead frames 310 to 380. Therefore, the bonding force of the molded resin portion 800 is more likely to act on the portions where the organic insulating films 600 and 700 are not interposed between the metal conductor bases 100 and 200 and the lead frames 310 to 380, and peeling of these portions can be suppressed. Thus, the reliability of the semiconductor device 1 can be ensured.

[0129] As a modification, the joint portions 410 to 430 can not be integrally formed with the lead frames 310, 350, and 370 in advance. That is, the joint portions 410 to 430 can be configured as components separate from the lead frames 310, 350, and 370. Alternatively, each of the joint portions 410 to 430 can be integrally formed with the lead frames 340, 360, and 380 in advance. In this case, the joint portions 410 to 430 are connected to the lead frames 310, 350, and 370 in a connection process.

[0130] As a variation, each of the base-side films 610, 710 and each of the films 620, 630, 720, 730 can be composed of multiple layers instead of one layer.

[0131] The first metal conductor base 100, the first surface 101, and the second surface 102 correspond to a metal conductor base, a first surface, and a second surface, respectively. The first joint portion 410, the first end portion 411, and the second end portion 412 correspond to a joint portion, a first end portion, and a second end portion, respectively. Further, the first organic insulating film 600 corresponds to an organic insulating film, and the first base-side film 610 corresponds to a base-side film.

[0132] (Second Embodiment)

[0133] In the present embodiment, portions different from the first embodiment will be mainly described. When the present inventors studied the relationship between the drying temperature and the shear strength, it was found that the shear strength varies depending on the drying temperature. The drying time was, for example, 60 minutes. The results are shown in Figure 23 .

[0134] As shown in Figure 23 , by heating the first base-side film 610, the first film 620, and the second film 630 in a temperature range of 225°C to 275°C, a high shear strength can be obtained. It is presumed that this is because the adhesion is inhibited by the NMP remaining when the drying temperature is lower than 225°C. Further, it is presumed that the adhesion is inhibited because the curing reaction is completed at a drying temperature exceeding 275°C.

[0135] Accordingly, in the dry molding process, the first base side film 610, the first film 620, and the second film 630 are heated at a temperature in the range of 225°C to 275°C. At this temperature condition, high shear strength can be obtained by semi-curing the first base side film 610, the first film 620, and the second film 630.

[0136] The second base side film 710, the third film 720, and the fourth film 730 are also semi-cured according to the above condition.

[0137] (Other Embodiments)

[0138] The structure of the semiconductor device 1 according to the above embodiments is an example of the present disclosure, and the structure is not limited and can be implemented by other structures within the present disclosure. For example, in each of the above embodiments, a double-sided heat dissipation structure that dissipates heat from both the metal conductor bases 100 and 200 is demonstrated, but for example, a single-sided heat dissipation structure that dissipates heat from the first metal conductor base 100 can also be employed. Further, the number of first wiring terminals 321 can be one. Similarly, the number of second wiring terminals 331 can be one.

[0139] In each of the above embodiments, a structure in which six power elements 510 to 560 are formed integrally is employed, but for example, a structure in which two power elements 510, 520 are formed integrally can also be employed. Alternatively, a structure in which four power elements 510 to 540 are formed integrally can also be employed.

[0140] In each of the above embodiments, a pressing pressure is applied during the full curing process, but the pressing pressure can also not be applied.

Claims

1. A semiconductor device, comprising: A metal conductor base (100) having a first surface (101) and a second surface (102) located on the opposite side of the first surface (101); A first lead frame (310) is fixed to the first surface of the metal conductor base; The second lead frame (320) is fixed to the first surface of the metal conductor base and disposed away from the first lead frame; A third lead frame (330) is disposed above the first lead frame in a thickness direction perpendicular to the first surface of the metal conductor base; A fourth lead frame (340) is disposed above the second lead frame in the thickness direction; The connector (410) has a first end (411) and a second end (412) located on the opposite side of the first end. The first end is integrally formed with the first lead frame, and the second end is integrally formed with the fourth lead frame. The connector electrically connects the first lead frame and the fourth lead frame. A first power element (510) is disposed between the first lead frame and the third lead frame and is electrically connected to the first lead frame and the third lead frame; A second power element (520) is disposed between the second lead frame and the fourth lead frame and is electrically connected to the second lead frame and the fourth lead frame; and A molding resin portion (800) integrally seals a portion of the metal conductor base, the first lead frame, the second lead frame, the first power element, the second power element, the connector portion, the third lead frame, and the fourth lead frame, wherein the second surface of the metal conductor base is exposed from the molding resin portion. The first lead frame is fixed to the first surface of the metal conductor base, and the second lead frame is fixed to the first surface of the metal conductor base, by means of an organic insulating film (600) made of polyimide-based material. The organic insulating film satisfies the following relationship: t press1 >t cast1 and t press2 >t cast1 , where t press1 The thickness t is the portion of the organic insulating film sandwiched between the metal conductor base and the first lead frame. press2 It is the thickness of the portion of the organic insulating film sandwiched between the metal conductor base and the second lead frame, and t cast1 It is the thickness of the portion of the organic insulating film that is not sandwiched between the metal conductor base and the first lead frame, and that is not sandwiched between the metal conductor base and the second lead frame.

2. The semiconductor device according to claim 1, wherein... The area of ​​the first surface of the metal conductor base is greater than the sum of the area of ​​the mounting surface of the first lead frame to the first surface of the metal conductor base and the area of ​​the mounting surface of the second lead frame to the first surface of the metal conductor base. The first lead frame and the second lead frame are disposed on the inner side of the outer edge of the first surface of the metal conductor base.

3. The semiconductor device according to claim 1, wherein... The organic insulating film includes a base-side film (610), a first film (620), and a second film (630). The base-side membrane is disposed on the first surface of the metal conductor base. The first membrane is disposed on the mounting surface of the first lead frame, which is mounted to the first surface of the metal conductor base. The second film is disposed on the mounting surface of the second lead frame, which is mounted to the first surface of the metal conductor base, and The surface portions of the first membrane and the second membrane are chemically bonded to the surface portion of the base-side membrane by forming a polymer.

4. The semiconductor device according to claim 1, wherein The organic insulating film has a Young's modulus of less than 20 GPa, and The ratio of the mounting side volume to the base conductor volume is 7.0 or less, wherein the mounting side volume is the sum of the volumes of the first lead frame and the second lead frame, and the base conductor volume is the volume of the metal conductor base.

5. The semiconductor device according to claim 1, further comprising: The first wiring terminal (321) has a first connecting portion (322) and a first front end portion (323) located on the opposite side of the first connecting portion; and The second wiring terminal (331) has a second connecting portion (332) and a second front end portion (333) located on the opposite side of the second connecting portion, wherein The first connecting portion of the first wiring terminal is integrally formed with the second lead frame. The first front end of the first wiring terminal is disposed opposite to the first lead frame and the second lead frame in the setting direction along which the first lead frame and the second lead frame are disposed. A portion of the middle part between the first connecting portion and the first front end of the first wiring terminal is disposed between the first lead frame and the third lead frame, without contacting the first lead frame, the third lead frame, and the first power element. The second connection portion of the second wiring terminal is integrally formed with the third lead frame. The second front end of the second wiring terminal is disposed opposite to the third lead frame and the fourth lead frame in the setting direction, and The molding resin portion seals the first wiring terminal and the second wiring terminal, with the first front end of the first wiring terminal and the second front end of the second wiring terminal exposed from the molding resin portion.

6. The semiconductor device according to claim 1, wherein The first lead frame, the second lead frame, the third lead frame, the fourth lead frame, the connector, the first power element, and the second power element are included in each of the three groups. The three sets are arranged on the first surface of the metal conductor base in a direction perpendicular to the setting direction, and the first lead frame and the second lead frame are arranged on the first surface of the metal conductor base along the setting direction. The second lead frame in the three groups is integrally formed into a lead frame, and The third lead frame in the three groups is integrally formed into a single lead frame.

7. The semiconductor device according to any one of claims 1 to 6, wherein the metal conductor substrate is defined as a first metal conductor substrate and the organic insulating film is defined as a first organic insulating film, the semiconductor device further comprising: A second metal conductor base (200) has a first surface (201) and a second surface (202) located opposite to the first surface, wherein The third lead frame and the fourth lead frame are fixed to the first surface of the second metal conductor base so as to be far apart from each other. The molded resin portion seals the portion of the first metal conductor base, the first lead frame, the second lead frame, the first power element, the second power element, the connector, the third lead frame, the fourth lead frame, and the portion of the second metal conductor base, with the second surfaces of the first and second metal conductor bases exposed from the molded resin portion. The fixing of the third lead frame to the first surface of the second metal conductor base and the fixing of the fourth lead frame to the first surface of the second metal conductor base are ensured by a second organic insulating film (700) made of polyimide-based material, and The second organic insulating film satisfies the following relationship: t press3 >t cast2 and t press4 >t cast2 , where t press3 It is the thickness of the portion of the second organic insulating film sandwiched between the second metal conductor base and the third lead frame, t press4 It is the thickness of the portion of the second organic insulating film sandwiched between the second metal conductor base and the fourth lead frame, and t cast2 It is the thickness of the portion of the second organic insulating film that is not sandwiched between the second metal conductor base and the third lead frame, and that is not sandwiched between the second metal conductor base and the fourth lead frame.

8. A method for manufacturing a semiconductor device, the semiconductor device comprising: A metal conductor base (100) having a first surface (101) and a second surface (102) located on the opposite side of the first surface (101); A first lead frame (310) is fixed to the first surface of the metal conductor base by an organic insulating film (600) made of polyimide-based material; The second lead frame (320) is fixed to the first surface of the metal conductor base by the organic insulating film and disposed away from the first lead frame; A third lead frame (330) is disposed above the first lead frame in a thickness direction perpendicular to the first surface of the metal conductor base; A fourth lead frame (340) is disposed above the second lead frame in the thickness direction; The connector (410) has a first end (411) and a second end (412) located on the opposite side of the first end. The first end is integrally formed with the first lead frame, and the second end is integrally formed with the fourth lead frame. The connector electrically connects the first lead frame and the fourth lead frame. A first power element (510) is disposed between the first lead frame and the third lead frame and is electrically connected to the first lead frame and the third lead frame; A second power element (520) is disposed between the second lead frame and the fourth lead frame and is electrically connected to the second lead frame and the fourth lead frame; and A molding resin portion (800) integrally seals a portion of the metal conductor base, the first lead frame, the second lead frame, the first power element, the second power element, the connector portion, the third lead frame, and the fourth lead frame, wherein the second surface of the metal conductor base is exposed from the molding resin portion. The manufacturing method includes: Prepare the metal conductor base, the first lead frame, and the second lead frame; The first surface of the metal conductor base is coated with a base-side film (610) made of polyimide resin, the mounting surface of the first lead frame that is mounted to the first surface of the metal conductor base is coated with a first film (620) made of polyimide resin, and the mounting surface of the second lead frame that is mounted to the first surface of the metal conductor base is coated with a second film (630) made of polyimide resin. The base-side film, the first film, and the second film are dried to partially cure the base-side film, the first film, and the second film. The base-side membrane is bonded to the first membrane, and the base-side membrane is bonded to the second membrane; The base-side film, the first film, and the second film are cured to form the organic insulating film; and The third lead frame is arranged above the first lead frame in the thickness direction, and the fourth lead frame is arranged above the second lead frame in the thickness direction. The first lead frame and the fourth lead frame are electrically connected through the connector. The curing of the base-side film, the first film, and the second film includes forming the organic insulating film to satisfy the following relationship: t press1 >t cast1 and t press2 >t cast1 , where t press1 The thickness t is the portion of the organic insulating film sandwiched between the metal conductor base and the first lead frame. press2 It is the thickness of the portion of the organic insulating film sandwiched between the metal conductor base and the second lead frame, and t cast1 It is the thickness of the portion of the organic insulating film that is not sandwiched between the metal conductor base and the first lead frame, and that is not sandwiched between the metal conductor base and the second lead frame.

9. The manufacturing method according to claim 8, wherein The coating of the base-side film, the first film, and the second film includes applying a solution containing a solvent. The drying of the base-side membrane, the first membrane, and the second membrane includes bringing the base-side membrane, the first membrane, and the second membrane to a state satisfying the relationship 0.01P. VP <P<P VP P VP =10 (9.368-3477 / (273.15+T)) Semi-cured at T≥100℃, wherein, T is the temperature of the solvent, P VP P is the vapor pressure of the solvent relative to the temperature T, and P is the vacuum pressure in which the base-side membrane, the first membrane, and the second membrane are disposed.

10. The manufacturing method according to claim 8, wherein The drying of the base-side film, the first film, and the second film includes semi-curing the base-side film, the first film, and the second film by heating them in a temperature range of 225°C to 275°C.

11. The manufacturing method according to any one of claims 8 to 10, wherein The curing of the base-side film, the first film, and the second film is performed under conditions where the pressing pressure between the metal conductor base and the first lead frame exceeds 5 MPa and the pressing pressure between the metal conductor base and the second lead frame exceeds 5 MPa, in order to form the organic insulating film.

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