METHOD FOR PRODUCING A SEMICONDUCTOR MODULE

Abstract

A method for forming a semiconductor module (20) is provided. The method comprises the following steps: providing a discrete semiconductor chip (30, 32, 34) having a package (38) and one or more leads (36) extending from the package (38); providing a device (40) having one or more recesses (42); coupling the discrete semiconductor chip (30, 32, 34) to the device (40) such that the leads (36) are arranged in the recesses (42); providing a carrier (22); placing a resin plate (24) on the carrier (22); placing the discrete semiconductor chip (30, 32, 34) on the resin plate (24); placing a vacuum film (70) over the carrier (22) and the discrete semiconductor chip (30, 32, 34); Arranging the carrier (22), the resin plate (24) and the semiconductor chip (30, 32, 34) with the vacuum film (70) in a chamber (82) of an autoclave (80); evacuating the cavity (78);Pressurizing the chamber (82) with gas at a temperature sufficient to fix the resin plate (24) to the support (22); releasing the gas from the chamber (82); removing the support (22), the resin plate (24), and the discrete semiconductor chip (30, 32, 34) with the vacuum film (70) from the chamber (82); removing the vacuum film (70) from the support (22), the resin plate (24), and the discrete semiconductor chip (30, 32, 34); and removing the device (40) from the discrete semiconductor chip (30, 32, 34).

Description

[0001] The invention relates to a method for producing a semiconductor module.

[0002] A conventional semiconductor module may include a carrier, one or more discrete semiconductor chips mounted on the carrier, an electrically insulating and thermally conductive coupling structure that thermally and mechanically couples the discrete semiconductor chips to the carrier, and a driver board for driving the discrete semiconductor chips. The driver board is mechanically coupled to the carrier and electrically coupled to the semiconductor chips. The semiconductor module may be, or be used in, a rectifier or an inverter.

[0003] The carrier may include or consist of a heat sink. The carrier may include or consist of copper or aluminum.

[0004] The coupling structure may comprise an electrically insulating ceramic plate, a first layer of thermally conductive grease between the carrier and the ceramic plate, and a second layer of thermally conductive grease between the ceramic plate and the discrete semiconductor chips. The thermally conductive paste may have a thermal conductivity of 3 to 6 W / mK. The coupling structure may further comprise one or more screws for mechanically coupling the discrete semiconductor chips to the carrier. For example, the discrete semiconductor chips may each have a through-hole for at least partially receiving a corresponding one of the screws, wherein a portion of the screws protruding from the through-holes may be mechanically coupled to the carrier.

[0005] The discrete semiconductor chips can be configured as high-performance semiconductor chips. The discrete semiconductor chips can comprise SiC and / or GaN and / or can be configured as wide band gap (WBG) chips. The discrete semiconductor chips can each comprise one or more legs, which protrude from a housing of the corresponding discrete semiconductor chip, in particular in a direction parallel to a surface of the carrier on which the discrete semiconductor chips are arranged. Each of the legs can provide an electrical contact of the corresponding discrete semiconductor chip.For example, one of the legs may form a gate contact of the corresponding discrete semiconductor chip, another of the legs may form a source contact of the corresponding discrete semiconductor chip, and another of the legs may form a drain contact of the corresponding discrete semiconductor chip. The discrete semiconductor chips may be electrically coupled in parallel, e.g., to provide high current and / or high power.

[0006] The driver board may include one or more electronic components coupled to the semiconductor chips. The electronic components may be active electronic components and / or passive electronic components. The passive electronic components may include a resistor, a capacitor, and / or a conductor. The active electronic components may include a chip and / or a transistor.

[0007] In general, it is already known to couple a "normal" semiconductor chip, e.g., an SMD chip (SMD - Surface Mounted Device), which has legs that extend perpendicular to the surface of the carrier, to a carrier in an autoclave process. In such a process, the semiconductor chip can be arranged on a carrier, and a vacuum bagging film can be arranged around the semiconductor chip and the carrier. The vacuum bagging film can then be evacuated, so that pressure is applied from the semiconductor chip to the carrier. However, the autoclave process has not been usable to date with discrete semiconductor chips with legs that protrude parallel to the surface of the carrier because the vacuum bagging film can tilt the discrete semiconductor chip relative to the carrier by pressing on the legs during evacuation and / or because the vacuum bagging film can inadvertently bend the legs out of shape during evacuation.

[0008] Furthermore, the ceramic plate and the layers of thermally conductive grease may not be suitable for coupling the discrete semiconductor chips to the carrier during the autoclave process. Therefore, an additional layer of adhesive or solder may be required to fix the discrete semiconductor chips to the carrier, especially during the autoclave process.

[0009] Furthermore, if the discrete semiconductor chips are high-performance semiconductor chips, the thermal conductivity of the grease may not be sufficient to adequately dissipate heat generated during operation of the semiconductor module. This may impair the performance of the discrete semiconductor chips.

[0010] Therefore, it is an object of the present invention to provide a method for forming a semiconductor module comprising at least one discrete semiconductor chip having a package and legs protruding from the package, which method is simple and cost-effective, which can be carried out quickly, which helps to properly fix the discrete semiconductor chip to a carrier of the semiconductor module, which helps to prevent the legs from being accidentally bent out of shape, and / or which can enable high performance of the discrete semiconductor chips.

[0011] The object is achieved by the subject matter of the independent claims. Advantageous embodiments are recited in the dependent claims.

[0012] One aspect relates to a method for manufacturing a semiconductor module. The method comprises the following steps: providing a discrete semiconductor chip having a housing and one or more legs protruding from the housing, wherein the legs form electrical contacts of the discrete semiconductor chip; providing a device having one or more recesses, wherein the recesses are formed and arranged such that the legs of the discrete semiconductor chip can be at least partially arranged in the recesses; coupling the discrete semiconductor chip to the device such that the legs are arranged in the recesses; providing a carrier; arranging a resin plate on the carrier; arranging the discrete semiconductor chip on the resin plate;Placing a vacuum film over the carrier and the discrete semiconductor chip such that a cavity is formed at least between the carrier, the discrete semiconductor chip, and the vacuum film; arranging the carrier, the resin plate, and the semiconductor chip with the vacuum film in a chamber of an autoclave; evacuating the cavity; pressurizing the chamber with gas having a temperature sufficient to fix the resin plate to the carrier; releasing the gas from the chamber; removing the carrier, the resin plate, and the discrete semiconductor chip with the vacuum film from the chamber; removing the vacuum film from the carrier, the resin plate, and the discrete semiconductor chip; and removing the device from the discrete semiconductor chip, wherein the discrete semiconductor chip mounted on the resin plate on the carrier forms the semiconductor module.

[0013] The vacuum film provides uniform pressure to the surrounding components due to the evacuated cavity and the pressurized chamber. Due to the high temperature in the chamber and due to the pressure, the resin plate is fixed to the carrier and the discrete semiconductor chips are fixed to the resin plate. Thus, the vacuum film can enable the resin plate to be fixed to the carrier and the discrete semiconductor chip to the resin plate simultaneously. Therefore, the process can be carried out quickly, easily, and cost-effectively. Furthermore, the device can protect the legs of the discrete semiconductor chip while the pressure is applied by the vacuum film. Thus, the discrete semiconductor chip cannot be tilted via its legs due to the vacuum film during evacuation, and / or the legs cannot be accidentally bent out of shape during the autoclave process.Furthermore, the material of the resin plate can be selected such that the thermal conductivity of the resin plate can be much higher than the thermal conductivity of a thermal paste, as used in the aforementioned prior art. This contributes to the heat generated during operation of the semiconductor module being sufficiently dissipated from the discrete semiconductor chips. This contributes to the discrete semiconductor chips, and thus the semiconductor module, being able to operate at high power.

[0014] The semiconductor module may be part of a power converter, e.g., an inverter or a rectifier. The semiconductor module may include a driver board for driving the discrete semiconductor chips, wherein the driver board may be mechanically coupled to the carrier and electrically coupled to the semiconductor chips. The driver board may include one or more electronic components coupled to the semiconductor chips. The electronic components may be active electronic components and / or passive electronic components. The passive electronic components may include a resistor, a capacitor, and / or a conductor. The active electronic components may include a chip and / or a transistor.

[0015] The discrete semiconductor chip can be coupled to the device before or after arranging the discrete semiconductor chip on the resin plate on the carrier. No additional material, even adhesive or solder, may be provided between the discrete semiconductor chip and the resin plate, nor between the resin plate and the carrier. In other words, the discrete semiconductor chip can be arranged directly on the resin plate and / or touch the resin plate, and / or the resin plate can be arranged directly on the carrier and / or touch the carrier. After removing the vacuum film from the carrier, the resin plate, and the discrete semiconductor chip, the device can be removed from the legs of the discrete semiconductor chip, whereby the discrete semiconductor chip mounted on the resin plate on the carrier forms the semiconductor module.Optionally, the legs of the discrete semiconductor chip of the final semiconductor module may be intentionally bent, e.g., such that they extend perpendicularly with respect to the surface of the carrier on which the discrete semiconductor chip is arranged, e.g., in a direction away from the surface.

[0016] The resin plate can be configured to fix the discrete semiconductor chip to the carrier when high temperature and high pressure are applied to the discrete semiconductor chip and the carrier. Thus, the resin plate can be considered as an adhesive layer for fixing the discrete semiconductor chip to the carrier, where the adhesive property can be activated by the high temperature. For example, the resin plate can soften or even partially melt at the high temperature and can harden when the autoclave process is completed and the resin plate cools down. The resin plate can provide thermal and mechanical coupling between the discrete semiconductor chip and the carrier. A thermal conductivity of the resin plate can be more than 10 kW / m. A breakdown voltage of the resin plate can be more than 4 kV DC.

[0017] The discrete semiconductor chip may be a high-performance semiconductor chip. The discrete semiconductor chips may comprise SiC and / or GaN and / or may be configured as WBG (Wide Band Gap) chips. The discrete semiconductor chip may be a discrete IGBT. For example, the semiconductor chip may be configured to handle currents above 10 A. In addition to the semiconductor chip, one or more further semiconductor chips may be arranged on the resin plate, in particular by means of the device, wherein the device may have a corresponding number of recesses for at least partially receiving the legs of the corresponding discrete semiconductor chips. The discrete semiconductor chips may be electrically coupled in parallel, e.g., via the carrier, via the driver board, and / or via one or more wire bonds, e.g., to provide high current and / or high power.With more than one discrete semiconductor chip, the device can ensure that the discrete semiconductor chips have a precise position relative to each other and a precise spacing from each other, because the relative position of the discrete semiconductor chips can be determined by the relative positions of the recesses in the device. This can contribute to the ease of manufacturing the semiconductor module.

[0018] One of the legs of the discrete semiconductor chip may form a gate contact of the corresponding discrete semiconductor chip, and another of the legs may form a source contact of the corresponding discrete semiconductor chip, and another of the legs may form a drain contact of the corresponding discrete semiconductor chip.

[0019] The carrier may comprise or be made of copper or aluminum. The carrier may be a heat sink of the semiconductor module.

[0020] The vacuum film can be coupled in a gas-tight manner to a lateral side surface of the device or to a lower surface of the device, such that at least a portion of the lower surface of the device is free of the vacuum film. Alternatively, the vacuum film can completely enclose the device, the carrier, and the discrete semiconductor chip.

[0021] According to one embodiment, the vacuum film is arranged such that the device is at least partially enclosed by the vacuum film. This can enable handling of the arrangement of the carrier and the discrete semiconductor chips in the vacuum film by handling the device. In particular, the device can be touched from the outside without touching the vacuum film.

[0022] According to one embodiment, the vacuum film is arranged such that it is coupled to the device in a gas-tight manner. This can enable evacuation of the cavity, especially when the vacuum film is coupled to the device.

[0023] According to one embodiment, the vacuum film is coupled to the device in a gas-tight manner by a vacuum sealant. This contributes to the gas-tight arrangement of the vacuum film.

[0024] According to one embodiment, a gas outlet for evacuating the cavity extends through the device, and the cavity is sealed gas-tight by the device and the vacuum film, with the exception of the gas outlet. In particular, the device may comprise a continuous recess that forms the gas outlet or that accommodates a tube that forms the gas outlet. The gas outlet may be coupled to the device in a gas-tight manner. The gas outlet may be coupled to the device before or after the vacuum film is arranged over the carrier and the discrete semiconductor chip. The gas outlet may be configured to communicate with the cavity and with a vacuum pump. The gas outlet may extend from the cavity to the vacuum pump. After evacuating the cavity and before pressurizing the chamber, the gas outlet may be closed and disconnected from the vacuum pump.Alternatively, the gas outlet can be coupled to the vacuum pump until the carrier and the discrete semiconductor chip with the vacuum film are removed from the chamber.

[0025] According to one embodiment, a direction in which the legs extend is parallel to a surface of the carrier on which the resin plate is disposed when the discrete semiconductor chip is disposed on the carrier. Furthermore, the legs may protrude from the carrier when the discrete semiconductor chip is disposed on the carrier. After fixing the discrete semiconductor chips to the carrier in the autoclave process, the legs may be intentionally bent, e.g., such that at least a portion of the legs extends perpendicular to the surface of the carrier.

[0026] According to one embodiment, a distance from one of the recesses to another of the recesses corresponds to a distance from one of the legs to another of the legs. This makes it possible to arrange all of the legs of the discrete semiconductor chip in the corresponding recesses.

[0027] According to one embodiment, the discrete semiconductor chip has three legs, and the device has three recesses for receiving the legs of the discrete semiconductor chip. If the semiconductor module comprises more than one discrete semiconductor chip, the device can correspondingly comprise more recesses for receiving the legs of the correspondingly more discrete semiconductor chips. For example, if n discrete semiconductor chips are arranged and if each of these discrete semiconductor chips has three legs, the device can comprise n*3 recesses, where n is a natural number.

[0028] According to one embodiment, the recesses are formed such that a press fit is provided between the legs and the recesses when the legs are arranged in the corresponding recesses. This can help ensure that the discrete semiconductor chips can be easily coupled to the device by simply pressing the legs into the corresponding recesses. The discrete semiconductor chips can then be easily handled by handling the device that holds the discrete semiconductor chips.

[0029] According to one embodiment, the depth of the recesses is less than the length of the legs. This can help maintain a given distance between the device and the housing of the discrete semiconductor chips. This can facilitate arranging the semiconductor chips with their legs in the recesses of the device on the carrier.

[0030] According to one embodiment, the recesses are arranged along a straight line and / or the legs are arranged along a straight line. When the legs are arranged in the recesses, these straight lines run parallel to each other. This can contribute to easy coupling of the discrete semiconductor chips to the device.

[0031] According to one embodiment, one or more discrete semiconductor chips are provided, each comprising a housing and one or more legs protruding from the housing, the legs forming electrical contacts of the corresponding discrete semiconductor chips; the device comprises correspondingly more recesses, the recesses being formed and arranged such that the legs of the discrete semiconductor chips can be at least partially arranged in the recesses; the discrete semiconductor chips are coupled to the device such that the legs are arranged in the recesses; the discrete semiconductor chips are arranged on the resin plate; and the vacuum film is arranged over the carrier and the discrete semiconductor chips such that the cavity is formed at least between the carrier, the discrete semiconductor chips and the vacuum film.Each of the discrete semiconductor chips may correspond to the discrete semiconductor chip explained above.

[0032] The device may be in the form of a rod with a longitudinal extension, and the recesses may be arranged along a straight line parallel to the longitudinal extension of the rod. When the discrete semiconductor chips are coupled to the device such that the legs are arranged in the recesses, the discrete semiconductor chips are arranged side by side in a row, with the row extending in the longitudinal extension of the rod. The rod-shaped device with the discrete semiconductor chips can be easily handled and, in particular, can enable the discrete semiconductor chips to be arranged simultaneously on the carrier.

[0033] According to one embodiment, the gas temperature in the chamber is between 50° and 300°, e.g., between 80° and 250°, e.g., at 120°. Alternatively or additionally, an overpressure in the pressurized chamber is between 10 kPa and 100 MPa, e.g., between 100 kPa and 1 MPa above atmospheric pressure. Alternatively or additionally, a negative pressure in the evacuated space is between 10 -3 hPa and 10 -6 hPa, e.g. between 10 -4 hPa and 10 -6 hPa. This helps to ensure that after the autoclave process, the discrete semiconductor chips are securely fixed to the resin plate and that the resin plate is securely fixed to the carrier.

[0034] These and other aspects of the invention will become apparent and explained with reference to the embodiments described below. Embodiments of the present invention will be described in more detail below with reference to the attached drawings. Fig. 1 shows a plan view of an embodiment of a semiconductor module. Fig. 2 shows a top view of discrete semiconductor chips of the semiconductor module of Fig. 1. Fig. 3 shows a cross-sectional view of an apparatus for manufacturing the semiconductor module of Fig. 1. Fig. 4 shows the discrete semiconductor chips of Fig. 2, which is attached to the device of Fig. 3 are arranged. Fig. Figure 5 shows the device with the discrete semiconductor chips according to Fig. 4, wherein the discrete semiconductor chips are arranged on an embodiment of a carrier. Fig. Figure 6 shows a cross-sectional side view of the discrete semiconductor chips on the device and on the carrier according to Fig. 5, which are partially enclosed by an embodiment of a vacuum film. Fig. 7 shows the Fig. 6 shown arrangement arranged in an autoclave.

[0035] The reference symbols used in the drawings and their meanings are summarized in the following list of reference symbols. Identical parts in the figures are generally provided with the same reference symbols.

[0036] Fig. 1 shows a top view of an embodiment of a semiconductor module 20. The semiconductor module 20 comprises a carrier 22, a thermally conductive and electrically insulating resin plate 24 on the carrier 22, and one or more discrete semiconductor chips, e.g., a first discrete semiconductor chip 30, a second discrete semiconductor chip 32, and a third discrete semiconductor chip 34, on the resin plate 24. Optionally, the semiconductor module 20 may comprise a driver board (not shown) having one or more electronic components, e.g., for driving the discrete semiconductor chips 30, 32, 34. The semiconductor module 20 may be part of a power converter, e.g., an inverter or a rectifier, and / or may be used for a half-bridge module.

[0037] Each of the discrete semiconductor chips 30, 32, 34 has a respective housing 38 and respective legs 36 protruding from the corresponding housing 38. The discrete semiconductor chips 30, 32, 34 may be high-performance semiconductor chips. The discrete semiconductor chips 30, 32, 34 may comprise SiC and / or GaN and / or may be configured as wide band gap (WBG) chips. The discrete semiconductor chips 30, 32, 34 may be discrete IGBTs. Alternatively, the semiconductor chips 30, 32, 34 may be transistors, e.g., FWDs or MOSFETs. The discrete semiconductor chips 30, 32, 34 may be electrically coupled in parallel, e.g., to provide high current and / or high power, e.g., B. via the carrier 22, via the driver board, and / or via one or more wire bonds (not shown). At least one of the discrete semiconductor chips 30, 32, 34 may be a high-performance semiconductor chip.The high-performance semiconductor chip 30, 32, 34 can be configured to process high voltages, for example, more than 100 V, and / or high currents, for example, more than 10 A. The discrete semiconductor chips 30, 32, 34.

[0038] The legs 36 form electrical contacts of the corresponding discrete semiconductor chip 30, 32, 34. One of the legs 36 of each of the discrete semiconductor chips 30, 32, 34 can form a gate contact of the corresponding discrete semiconductor chip 30, 32, 34, another of the legs 36 can form a source contact of the corresponding discrete semiconductor chip 30, 32, 34, and yet another of the legs 36 can form a drain contact of the corresponding discrete semiconductor chip 30, 32, 34. A direction in which the legs 36 can extend can be parallel to a surface of the carrier 22 on which the resin plate 24 is arranged. The discrete semiconductor chips 30, 32, 34 can be arranged on the carrier 22 such that the legs 36 are arranged along a straight line. The legs 36 may protrude from the carrier 22 in a lateral direction parallel to the surface of the carrier 22.The legs 36 may be intentionally bent (not shown), e.g., such that at least a portion of the legs 36 extends perpendicular to the surface of the carrier 22.

[0039] The carrier 22 may comprise or consist of copper or aluminum. The carrier 22 may be a heat sink of the semiconductor module 20.

[0040] No additional material, even adhesive or solder, may be provided between the discrete semiconductor chip and the resin plate, nor between the resin plate and the carrier. In other words, the discrete semiconductor chip may be directly disposed on the resin plate and / or may touch the resin plate, and / or the resin plate may be directly disposed on the carrier and / or may touch the carrier.

[0041] The resin plate 24 may be configured to fix the discrete semiconductor chips 30, 32, 34 to the carrier 22. Thus, the resin plate 24 may be considered an adhesive layer for fixing the discrete semiconductor chips 30, 32, 34 to the carrier 22. No additional material, even adhesive or solder, may be provided between the discrete semiconductor chips 30, 32, 34 and the resin plate 24, nor between the resin plate 24 and the carrier 22. In other words, the discrete semiconductor chips 30, 32, 34 may be arranged directly on the resin plate 24 and / or in such a way that they touch the resin plate 24, and / or the resin plate 24 may be arranged directly on the carrier 22 and / or in such a way that it touches the carrier 22. The resin plate 24 can provide thermal and mechanical coupling between the discrete semiconductor chips 30, 32, 34 and the carrier 22. The thermal conductivity of the resin plate 24 can be greater than 10 kW / m.The breakdown voltage of the resin plate 24 may exceed 4 kV DC. The resin plate 24 may have a thickness in a range from 300 µm to 10 mm, e.g., from 500 µm to 5 mm, e.g., from 1 mm to 3 mm.

[0042] The Fig. 2 to 7 show different states of the semiconductor module 20 during a method for manufacturing the semiconductor module 20. Furthermore, the Fig. 2 to 7 can be used to describe several steps of the corresponding procedure.

[0043] Fig. 2 shows a plan view of discrete semiconductor chips 30, 32, 34 of the semiconductor module 20 of Fig. 1. Fig. Figure 2 shows a first state of the semiconductor module 20 during its manufacture. In the first state, the discrete semiconductor chips 30, 32, 34 are provided. The discrete semiconductor chips 30, 32, 34 can be any discrete semiconductor chips 30, 32, 34 ready for use, as previously explained.

[0044] Fig. 3 shows a cross-sectional side view of an apparatus 40 for manufacturing the semiconductor module 20 of Fig. 1. Fig. Figure 3 shows a second state of the semiconductor module 20 during its manufacture. In the second state, the device 40 is provided.

[0045] The device 40 has a plurality of recesses 42, wherein the recesses 42 are formed and arranged such that the legs 36 of the discrete semiconductor chips 30, 32, 34 can be at least partially arranged in the recesses 42. The recesses 42 can be arranged along a straight line. A distance from one of the recesses 42 to another of the recesses 42, in particular to the next adjacent recess 42, can correspond to a distance from one of the legs 36 to another of the legs 36, in particular to the next adjacent leg 36. A depth of each of the recesses 42 can be less than a length of each of the legs 36. The device 40 can have the shape of a rod with a longitudinal extension, and the recesses 42 can be arranged along the straight line running parallel to the longitudinal extension of the rod.

[0046] A gas outlet 44 may extend through the device 40. In particular, the device 40 may include a through-hole that forms the gas outlet 44 or that receives a tube that forms the gas outlet 44. The gas outlet 44 may be configured to communicate with a vacuum pump (not shown).

[0047] Fig. 4 shows the discrete semiconductor chips 30, 32, 34 of Fig. 2, which is attached to the device of Fig. 3 are arranged. Fig. 4 shows a third state of the semiconductor module 20 during its manufacture. In the third state, the discrete semiconductor chips 30, 32, 34 are coupled to the device 40 such that the legs 36 are arranged in the recesses 42. The recesses 42 can be formed such that a press-fit connection is provided between the legs 36 and the corresponding recesses 42 when the legs 36 are arranged in the recesses 42.

[0048] Fig. 5 shows the device 40 with the discrete semiconductor chips 30, 32, 34 according to Fig. 4, wherein the discrete semiconductor chips 30, 32, 34 are mounted on an embodiment of a carrier, e.g., the one described with reference to Fig. 1 explained carrier 22. Fig. 5 shows a fourth state of the semiconductor module 20 during its manufacture. In the fourth state, the carrier 22 is provided, the resin plate 24 is arranged on the carrier 22, and the discrete semiconductor chips 30, 32, 34 are arranged on the resin plate 24. Thus, the fourth state represents four steps of the method for manufacturing the semiconductor module 20.

[0049] As in the Fig. 2 to 5, the discrete semiconductor chips 30, 32, 34 may be coupled to the device 40 before arranging the discrete semiconductor chips 30, 32, 34 on the resin plate 24 on the carrier 22. Alternatively, the discrete semiconductor chips 30, 32, 34 may be coupled to the device 40 after arranging the discrete semiconductor chips 30, 32, 34 on the resin plate 24 on the carrier 22.

[0050] No additional material, even adhesive or solder, may be provided between the discrete semiconductor chips 30, 32, 34 and the resin plate 24, nor between the resin plate 24 and the carrier 22. In other words, the discrete semiconductor chips 30, 32, 34 may be arranged directly on the resin plate 24, e.g., such that they touch the resin plate 24. Furthermore, the resin plate 24 may be arranged directly on the carrier 22, e.g., such that it touches the carrier 22. The resin plate 24 can be considered an adhesive layer for fixing the discrete semiconductor chips 30, 32, 34 to the carrier 22.

[0051] Fig. 6 shows a cross-sectional view of the discrete semiconductor chips 30, 32, 34 on the device 40 and on the carrier 22 according to Fig. 5, which are partially enclosed by an embodiment of a vacuum film 70. Fig. 6 shows a fifth state of the semiconductor module 20 during its manufacture. In the fifth state, the vacuum film 70 can be arranged over the carrier 22 and the discrete semiconductor chips 30, 32, 34, such that a cavity 78 is formed at least between the carrier 22, the discrete semiconductor chips 30, 32, 34, and the vacuum film 70.

[0052] The vacuum film 70 can be arranged such that the device 40 is at least partially enclosed by the vacuum film 70. The vacuum film 70 can be arranged such that it is coupled gas-tight to the device 40. The vacuum film 70 can be coupled gas-tight to a lateral side surface of the device 40 or to a lower surface of the device 40 (as in Fig. 6) such that at least a portion of the lower surface of the device 40 is free of the vacuum film 70. Alternatively, the vacuum film 70 may be arranged to completely enclose the device 40, the carrier 22, and the discrete semiconductor chips 30, 32, 34. The vacuum film 70 may be gas-tightly coupled to the device 40 by a vacuum sealing means 74.

[0053] The gas outlet 44 can be configured to evacuate the cavity 78. The gas outlet 44 can be formed and arranged such that one end of the gas outlet 44 opens into the cavity 78 and the other end of the gas outlet 44 opens into the vicinity of the vacuum film 70. The cavity 78 can then be sealed gas-tight by the device 40 and the vacuum film 70, with the exception of the gas outlet 44. The gas outlet 44 can be coupled to the device 40 before or after the vacuum film 70 is arranged over the carrier 22 and the discrete semiconductor chips 30, 32, 34. The gas outlet 44 can be configured to communicate with the cavity 78 and with a vacuum pump (not shown). The gas outlet 44 can extend from the cavity 78 to the vacuum pump.

[0054] Fig. 7 shows the Fig. 6, which is arranged in an autoclave 80, in particular in a chamber 82 of the autoclave 80. Fig. Fig. 7 shows a sixth state of the semiconductor module 20 during its manufacture. In the sixth state, the Fig. 6 is arranged in the chamber 82 of the autoclave 80, and an autoclave process is carried out as described below.

[0055] The cavity 78 between the plate 24, the discrete semiconductor chips 30, 32, 34, and the vacuum film 70 may be evacuated, as can be seen from the fact that the vacuum film 70 conforms to the discrete semiconductor chips 30, 32, 34, the resin plate 24, the carrier 22, and the device 40. The cavity 78 may be evacuated by the vacuum pump via the gas outlet 72.

[0056] Then, the chamber 82 can be pressurized with a gas, e.g., air, via a gas inlet 76 of the autoclave 80, so that an overpressure is generated in the chamber 82, wherein the gas has a high temperature sufficient to fix the plate 24 to the carrier 22. For example, a material of the resin plate 24 is selected such that the resin plate 24 can soften or even partially melt at the high temperature.

[0057] The positive pressure of the gas in the chamber 82 and the negative pressure in the cavity 78 ensure a predetermined pressure on the discrete semiconductor chips 30, 32, 34 to the resin plate 24 and on the resin plate 24 to the carrier 22. In this way, the discrete semiconductor chips 30, 32, 34 are fixed to the resin plate 24, and the plate 24 is fixed to the carrier 22.

[0058] After a predetermined period sufficient to properly fix the discrete semiconductor chips 30, 32, 34 to the resin plate 24 and the resin plate 24 to the carrier 22, the gas can be released from the chamber 82. Thereafter, the carrier 22, the resin plate 24, and the discrete semiconductor chips 30, 32, 34 surrounded by the vacuum film 70 can be removed from the chamber 82, and the vacuum film 70 can be removed from the carrier 22, the resin plate 24, and the discrete semiconductor chips 30, 32, 34.

[0059] After evacuating the cavity 78, e.g., by the vacuum pump, and before pressurizing the chamber 82, the gas outlet 72 can be closed and disconnected from the vacuum pump. Alternatively, the gas outlet 72 can remain coupled to the vacuum pump until the carrier 22, the resin plate 24, and the discrete semiconductor chips 30, 32, 34 with the vacuum film 70 are removed from the chamber 82. Then, the semiconductor module 20, as shown in Fig.1 shown, done.

[0060] The high gas temperature of the chamber 82 can be between 50° and 300°, e.g., between 80° and 250°, e.g., at 120°. The overpressure in the pressurized chamber can be between 10 kPa and 100 MPa, e.g., between 100 kPa and 1 MPa above atmospheric pressure. Alternatively or additionally, the negative pressure in the evacuated space can be between 10 -3 hPa and 10 -8 hPa, e.g. between 10 -4 hPa and 10 -6 hPa, lie.

[0061] Although the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered as illustrative or exemplary and not restrictive. In particular, the invention is not limited to the above embodiments. For example, there may be more or fewer discrete semiconductor chips 30, 32, 34, leads 36 per discrete semiconductor chip 30, 32, 34, and / or corresponding recesses 42 in the device 40. Other variations of the disclosed embodiments may be understood and practiced by those skilled in the art in practicing the claimed invention upon careful consideration of the drawings, the disclosure, and the appended claims.

[0062] In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" does not exclude a plural. The mere fact that certain measures are listed in different dependent claims does not mean that a combination of those measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of protection. List of reference symbols 20 semiconductor modules 22 carriers 24 resin plate 28 heat sinks 30 first discrete semiconductor chip 32 second discrete semiconductor chip 34 third discrete semiconductor chip 36 legs 38 housings 40 Device 42 recess 44 Gas outlet 70 vacuum film 74 Vacuum sealants 76 Gas inlet 78 cavity 80 The autoclave 82 Chamber

Claims

[1] A method for manufacturing a semiconductor module (20), the method comprising the following steps: Providing a discrete semiconductor chip (30, 32, 34) having a housing (38) and one or more legs (36) protruding from the housing (38), the legs (36) forming electrical contacts of the discrete semiconductor chip (30, 32, 34); Providing a device (40) having one or more recesses (42), wherein the recesses (42) are formed and arranged such that the legs (36) of the discrete semiconductor chip (30, 32, 34) can be arranged at least partially in the recesses (42); coupling the discrete semiconductor chip (30, 32, 34) to the device (40) such that the legs (36) are arranged in the recesses (42); Providing a carrier (22); Arranging a resin plate (24) on the carrier (22); Arranging the discrete semiconductor chip (30, 32, 34) on the resin plate (24); Arranging a vacuum film (70) over the carrier (22) and the discrete semiconductor chip (30, 32, 34) such that a cavity (78) is formed at least between the carrier (22), the discrete semiconductor chip (30, 32, 34) and the vacuum film (70); Arranging the carrier (22), the resin plate (24) and the semiconductor chip (30, 32, 34) with the vacuum film (70) in a chamber (82) of an autoclave (80); Evacuating the cavity (78); Pressurizing the chamber (82) with gas having a temperature sufficient to fix the resin plate (24) to the support (22); Releasing the gas from the chamber (82); Removing the carrier (22), the resin plate (24) and the discrete semiconductor chip (30, 32, 34) with the vacuum film (70) from the chamber (82); Removing the vacuum film (70) from the carrier (22), the resin plate (24) and the discrete semiconductor chip (30, 32, 34); and Removing the device (40) from the discrete semiconductor chip (30, 32, 34), wherein the discrete semiconductor chip (30, 32, 34) mounted on the resin plate (24) on the carrier (22) forms the semiconductor module (20). [2] Method according to claim 1, wherein the vacuum film (70) is arranged such that the device (40) is at least partially enclosed by the vacuum film (70). [3] Method according to claim 2, wherein the vacuum film (70) is arranged so that it is coupled to the device (40) in a gas-tight manner. [4] Method according to claim 3, wherein the vacuum film (70) is coupled gas-tight to the device (40) by a vacuum sealing means (74). [5] Method according to one of claims 2 to 4, wherein a gas outlet (44) for evacuating the cavity (78) extends through the device (40), and the cavity (78) is sealed gas-tight by the device (40) and the vacuum film (70) with the exception of the gas outlet (44). [6] A method according to any one of the preceding claims, wherein a direction in which the legs (36) extend is parallel to a surface of the carrier (22) on which the resin plate (24) is arranged when the discrete semiconductor chip (30, 32, 34) is arranged on the carrier (22). [7] Method according to one of the preceding claims, wherein a distance from one of the recesses (42) to another of the recesses (42) corresponds to a distance from one of the legs (36) to another of the legs (36). [8] Method according to one of the preceding claims, wherein the discrete semiconductor chip (30, 32, 34) has three legs (36); and the device (40) has three recesses (42) for receiving the legs (36) of the discrete semiconductor chip (30, 32, 34). [9] A method according to any one of the preceding claims, wherein the recesses (42) are formed such that an interference fit is provided between the legs (36) and the recesses (42) when the legs (36) are arranged in the corresponding recesses (42). [10] Method according to one of the preceding claims, wherein a depth of the recesses (42) is less than a length of the legs (36). [11] Method according to one of the preceding claims, wherein the recesses (42) are arranged along a straight line; and / or the legs (36) are arranged along a straight line. [12] A method according to any one of the preceding claims, wherein one or more discrete semiconductor chips (30, 32, 34) are provided, each having a housing (38) and one or more legs (36) projecting from the housing (38), the legs (36) forming electrical contacts of the corresponding discrete semiconductor chips (30, 32, 34); the device (40) has a correspondingly greater number of recesses (42), the recesses (42) being formed and arranged such that the legs (36) of the discrete semiconductor chips (30, 32, 34) can be arranged at least partially in the recesses (42); the discrete semiconductor chips (30, 32, 34) are coupled to the device (40) such that the legs (36) are arranged in the recesses (42); the discrete semiconductor chips (30, 32, 34) are arranged on the resin plate (24); and the vacuum film (70) is arranged over the carrier (22) and the discrete semiconductor chips (30, 32, 34) such that the cavity (78) is formed at least between the carrier (22), the discrete semiconductor chips (30, 32, 34) and the vacuum film (70). [13] Method according to one of the preceding claims, wherein the gas temperature in the chamber (82) is between 50° and 300°, e.g. between 80° and 250°, e.g. 120°, an overpressure in the pressurised chamber (82) is between 10 kPa and 100 MPa, e.g. between 100 kPa and 1 MPa above atmospheric pressure, and / or a negative pressure in the evacuated cavity (78) between 10 -3 hPa and 10 -8 hPa, e.g. between 10 -4 hPa and 10 -6 hPa, lies.

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