Heat dissipation substrate, power semiconductor module, and power converter

Abstract

The invention relates to a heat dissipation substrate, a power semiconductor module and a power converter. Embodiments relate to a heat dissipation substrate for a power semiconductor module, a power semiconductor module including the heat dissipation substrate, a power converter including the heat dissipation substrate, and a method of manufacturing the heat dissipation substrate. A heat dissipation substrate for a power semiconductor module according to an embodiment includes an insulating substrate, a lower metal plate disposed below the insulating substrate, and an upper metal plate disposed on the insulating substrate, in which the lower metal plate has a hollow structure.

Description

Technical Field

[0001] Embodiments relate to a heat dissipation substrate for a power semiconductor module, a power semiconductor module and a power converter including the heat dissipation substrate, and a method of manufacturing the heat dissipation substrate for a power semiconductor module.

[0002] In addition, the embodiments relate to a technology of a heat dissipation component used for a semiconductor device or the like. Background Art

[0003] Power conversion modules are used not only in environmentally friendly vehicles such as electric vehicles and fuel cell vehicles, but also in various electrical and electronic devices such as electric vehicle chargers, energy storage devices, power supply devices, or railways. Functions such as motor drive switching and power control.

[0004] A power conversion module includes various components such as power semiconductor devices, a heat dissipation substrate, a base plate, molded silicon, a housing, and terminals. However, the heat generated from the power semiconductor devices generates thermomechanical stresses in the various components of the power semiconductor module, and the life of the power semiconductor devices may be reduced due to thermal fatigue of the joints. Therefore, it is important to design the reliability of a power semiconductor module that dissipates the heat generated from the power semiconductor devices through the heat dissipation substrate to maintain the temperature of the power semiconductor device junction below an appropriate level.

[0005] Conventional heat dissipation substrates for power semiconductors can be categorized by bonding method into two methods: DBC (Direct Copper Bonding) and AMB (Active Metal Brazing). The DBC method forms an oxide film on a copper (Cu) layer and then directly bonds it to the ceramic, while the AMB method involves brazing a paste containing low-melting-point metal particles as an intermediate material between the base metal and the ceramic.

[0006] Recently, high-voltage / high-power SiC power conversion modules, such as 1200V and 200A, have been used to improve the performance of hybrid vehicles, electric vehicles, and autonomous vehicles. The operating temperature of the power semiconductor devices in these high-performance electric vehicles averages close to 300°C. Furthermore, the instantaneous maximum operating temperature approaches extremely high temperatures, ranging from 350°C to 700°C.

[0007] In such an ultra-high temperature, high voltage, and high current operating environment, existing bonding materials may remelt, and the presence of voids in the bonding area may cause heat sinks or drastically shorten the life of the power semiconductor module. Furthermore, these may lead to thermal runaway, which could damage the power semiconductor device and seriously affect driver safety.

[0008] In the prior art, in order to solve the heating problem of electronic devices such as power semiconductor modules, various heat dissipation components and heat dissipation modules such as heat sinks, heat dissipation plates, heat pipes, and heat spreaders are used.

[0009] For example, prior art 1 (US2020132392A1: 2020.04.30) is an invention relating to a “vapor chamber heat sink for power electronic components” (see patent document information in the following prior art documents).

[0010] Figure 1A yes Figure 2 FIG. 1 is a diagram related to a power electronic component 10 of prior art 1.

[0011] In Prior Art 1, each component of the power electronic assembly 10 is bonded via an adhesive layer 50. Specifically, the lower and upper sides of the electronic device 20 of Prior Art 1 are adhered to the substrate 21 and the spacer layer 70, respectively, via the adhesive layer 50. Furthermore, the upper side of the spacer layer 70 is adhered to the auxiliary substrate 21A via the adhesive layer 50. In Prior Art 1, the substrate 21 and the auxiliary substrate 21A are DBC (Direct Bonded Copper) heat dissipation substrates, in which a copper layer is directly bonded to the surface of a ceramic insulating substrate. Prior Art 1 includes a wire wiring 68 that electrically connects the gate electrode 66 to the electronic device 20.

[0012] Meanwhile, prior art 1 includes a substrate 21, an electronic device 20, a spacer layer 70, an auxiliary substrate 21A, wiring 68, and a gate electrode 66 encapsulated by a resin 69 and bonded to an adhesive layer 50. After encapsulation, a separately manufactured vapor chamber heat spreader 102 is applied to the cooling surface 24A of the substrate 21 and the cooling surface 24A of the auxiliary substrate 21A with thermal paste, and the vapor chamber heat spreader 102 is bonded together by an adhesive 80 containing thermal paste or a non-conductive material and performs a heat dissipation function. The vapor chamber heat spreader 102 includes an evaporator plate 104, a condenser plate 106, a side wall 108, a vapor chamber 110, a thermal compensation layer 130, and fins 126. The thermal compensation layer 130 increases heat capacity by including core-shell phase change particles.

[0013] Vapor chamber heat sink 102 of prior art 1 includes a working fluid disposed in vapor chamber 110. The working fluid has a vaporization temperature within the vapor chamber's operating temperature range. The working fluid evaporates at the evaporation surface of evaporator plate 104 and condenses at the condensation surface of condenser plate 106. The condensed working fluid is transported to evaporator plate 104 via capillary action along condenser plate 106, sidewalls 108, and / or fins 126, where it evaporates again at a hot spot on evaporator plate 104 to vaporize.

[0014] However, when vapor chamber heat sink 102, which is separately manufactured as in prior art 1, is adhered to substrate 21 or auxiliary substrate 21A via adhesive 80, there is a problem in that the heat transfer path from vapor emitted from electronic device 20 to vapor chamber heat sink 102 becomes longer. Furthermore, there is a problem in that a separate adhesive layer is interposed between vapor chamber heat sink 102 and substrate 21 or auxiliary substrate 21A, thereby generating thermal resistance and reducing heat transfer efficiency, so that evaporation of the working fluid does not occur properly, thereby resulting in a reduction in heat dissipation performance.

[0015] In addition, as in prior art 1, when a separately manufactured heat spreader 102 is bonded to the substrate 21 or the auxiliary substrate 21A by an adhesive 80, there is a problem of peeling of the bonding interface or warping of the component due to the difference in thermal expansion coefficient with the bonded substrate 21 or the auxiliary substrate 21A.

[0016] For example, Figure 1B 1 is a photograph showing the warpage WP that occurs after the AMB heat dissipation substrate is bonded to the base plate (BP) according to the comparative technology.

[0017] In the heat dissipation substrate manufactured using the comparative AMB technology, there are significant differences in the coefficient of thermal expansion (CTE) between the insulating substrate SS, the upper copper plate (T-Cu), the lower copper plate (B-Cu), the SiC chip, and the base plate (BP). For example, the CTE of the AlN insulating substrate SS is 4.5 x 10 -6 / ℃, the thermal expansion coefficient of upper and lower copper (T-Cu, B-Cu) is 16.0ⅹ10 -6 / ℃, and the thermal expansion coefficient of SiC chip is 4.0x10 -6 / ℃. However, in an ultra-high operating temperature environment of 300℃ or higher, if a difference in the thermal expansion coefficient of each component constituting the power semiconductor module occurs, Figure 1B If there is warpage (WP) or separation between interfaces as shown, the power semiconductor module may be damaged and may fail.

[0018] Therefore, when a separately manufactured vapor chamber heat sink 102 is bonded to the heat dissipation substrate 21 or auxiliary heat dissipation substrate 21A using adhesive 80, as in prior art 1, differences in the thermal expansion coefficients of the materials of the components can cause delamination at the bonding interface or warping of the components. Consequently, the heat dissipation function of the vapor chamber heat sink 102 is impaired, potentially leading to rapid deterioration of the power semiconductor module. This can lead to thermal runaway and damage to the power semiconductor device, potentially seriously impacting driver safety.

[0019] [Prior art literature]

[0020] [Patent Document]

[0021] U.S. patent publication number (publication date): US2020132392A1 (2020.04.30). Summary of the Invention

[0022] Because the vapor chamber heat sink is bonded to the heat dissipation substrate via adhesive, the heat transfer path from the heat-generating electronic device to the vapor chamber heat sink becomes longer. Furthermore, because a separate adhesive layer is inserted between the vapor chamber heat sink and the heat dissipation substrate, heat transfer efficiency is reduced due to thermal resistance. Therefore, one of the technical objectives of this embodiment is to address the issue of reduced heat dissipation performance of working fluid vapor chamber heat sinks.

[0023] Furthermore, since the heat dissipation substrate and the heat dissipation assembly are bonded together via an adhesive layer, differences in the thermal expansion coefficients of the bonded components can cause delamination at the bonded interface or warping of the assembly. Therefore, one of the technical objectives of the embodiments is to address the problem of power semiconductor module failures caused by differences in thermal expansion coefficients.

[0024] Technical purposes of the embodiments are not limited to those described in this section, and include those that can be understood from the description of the invention.

[0025] The heat dissipation substrate for a power semiconductor module according to an embodiment may include an insulating substrate, a lower metal plate disposed below the insulating substrate, and an upper metal plate disposed on the insulating substrate. The lower metal plate may include a hollow structure.

[0026] The lower metal plate may include a second metal plate joined to a bottom of the insulating substrate and a first metal plate joined to a bottom of the second metal plate.

[0027] The second metal plate may include a second-first metal plate having a plurality of first through-grooves arranged in a first direction and bonded to the insulating substrate. Alternatively, the second metal plate may include a second-second metal plate having a plurality of second through-grooves arranged in a second direction perpendicular to the first direction and bonded to a bottom portion of the second-first metal plate.

[0028] The first through groove and the second through groove may be three-dimensionally communicated to form a hollow structure.

[0029] The second-first metal plate may include a first body between a plurality of spaced-apart first through-grooves, and the second-second metal plate may include a second body between a plurality of spaced-apart second through-grooves.

[0030] The third metal plate may be thicker than the first metal plate or the second metal plate.

[0031] The third metal plate may include a circuit pattern on a surface thereof.

[0032] The first metal plate, the second metal plate, and the third metal plate may have the same metal material.

[0033] The second metal plate may be directly bonded to the bottom of the insulating substrate without an adhesive layer. The first metal plate may be directly bonded to the bottom of the second metal plate without an adhesive layer.

[0034] A power semiconductor module according to an embodiment may include any one of the above-described heat dissipation substrate and a power semiconductor device provided on an upper metal plate.

[0035] According to an embodiment, a method for manufacturing a heat dissipation substrate for a power semiconductor module may include: preparing an insulating substrate; preparing a first metal plate, a second metal plate, and a third metal plate; sequentially stacking the first metal plate and the second metal plate; stacking the insulating substrate on the second metal plate; preparing a stacked substrate group by stacking the third metal plate on the insulating substrate; and performing a hot pressing process on the stacked substrate group.

[0036] The second metal plate may include a second-first metal plate having a plurality of first through grooves arranged in the first direction. In addition, the second metal plate may include a second-second metal plate having a plurality of first through grooves arranged in the first direction and bonded to the insulating substrate.

[0037] Through the pressing process, the first through grooves and the second through grooves may be three-dimensionally communicated to form a hollow structure.

[0038] The second-first metal plate may include a first body between a plurality of spaced-apart first through-grooves, and the second-second metal plate may include a second body between a plurality of spaced-apart second through-grooves.

[0039] The second metal plate may be directly bonded to the bottom of the insulating substrate without an adhesive layer, and the first metal plate may be directly bonded to the bottom of the second metal plate without an adhesive layer.

[0040] Technical Effects

[0041] One of the technical effects of this embodiment is to solve the problem of deterioration of the heat dissipation performance of the working fluid vapor chamber heat sink caused by the vapor chamber heat sink being bonded to the heat dissipation substrate by an adhesive.

[0042] For example, according to embodiments, since the hot pressing process is performed in a high-temperature, high-pressure vacuum environment, a heat dissipation substrate can be integrally formed with a metal plate having a hollow structure HE that allows the working fluid to be filled within the heat dissipation substrate itself. Consequently, according to embodiments, the heat transfer path between the heat-generating power semiconductor devices and the metal plate HE having the hollow structure is significantly shortened, thereby improving heat transfer efficiency. As a result, the working fluid can be efficiently vaporized, significantly improving heat dissipation performance.

[0043] Furthermore, according to the embodiments, by implementing a heat dissipation substrate integrally equipped with a metal plate having a hollow structure HE capable of enclosing the working fluid within the heat dissipation substrate itself, thermal resistance can be reduced without requiring a separate adhesive layer. This results in improved heat transfer efficiency and significantly enhanced heat dissipation performance.

[0044] In addition, one of the technical effects of this embodiment is to solve the problem of failure of the power semiconductor module caused by the difference in thermal expansion coefficient, because the heat dissipation substrate and the heat dissipation component are bonded by the adhesive layer, causing peeling of the bonding interface or warping of the component.

[0045] Specifically, according to the embodiment, since the hot pressing process is performed in a high-temperature, high-pressure vacuum environment, there is a technical effect in that a metal plate can be formed integrally with the heat dissipation substrate, which has a hollow structure HE capable of enclosing the working fluid in the heat dissipation substrate itself.

[0046] For example, refer to Figure 2 According to the embodiment, the heat dissipation substrate 400 includes a second metal plate 422 having a hollow structure HE and a first metal integrally bonded to the underside of the second metal plate 422, such that the interface between the first metal plate 421 and the second metal plate 422 is substantially indistinguishable. Furthermore, the material of the second metal plate 422 having the hollow structure HE is the same as that of the first metal plate 421, which is integrally formed below the second metal plate 422. Thus, the difference in thermal expansion coefficient between the first metal plate 421 and the second metal plate 422 is resolved. A particular technical advantage is that, by fundamentally preventing delamination of the bonding interface or warping of the component, the reliability of the power semiconductor module can be significantly improved.

[0047] Furthermore, according to the embodiment, during the manufacturing process of the heat dissipation substrate 400, the edges of the sequentially stacked spacers, the first and second metal plates, the insulating substrate, and the third metal plate are aligned while undergoing a hot pressing process. Therefore, a special technical effect is achieved in that a high-quality heat dissipation substrate integrally equipped with a hollow structure HE can be realized.

[0048] Technical effects of the embodiments are not limited to those described in this section, and include those effects that can be understood through the description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1A yes Figure 2 FIG. 1 is a diagram related to a power electronic component 10 of prior art 1.

[0050] Figure 1B This is a photograph of the warpage (WP) that occurs after an AMB heat dissipation substrate according to a comparative technique is bonded to a base plate (BP).

[0051] Figure 2 is a cross-sectional view of a power semiconductor module 500 including a heat dissipation substrate for power semiconductors according to an embodiment.

[0052] Figure 3 is a cross-sectional view of a power semiconductor device 100 provided on a power semiconductor module according to an embodiment.

[0053] Figure 4 The present invention is a process flow chart of a process for manufacturing a heat dissipation substrate for power semiconductors according to an embodiment.

[0054] Figure 5 、 Figure 6 、 Figure 7A 、 Figure 7B 、 Figures 8 to 10 It is a cross-sectional view of a manufacturing process of a heat dissipation substrate for a power semiconductor according to an embodiment.

[0055] Figure 11A is a first cross-sectional view of a power semiconductor module 500 including a heat dissipation substrate for power semiconductors according to an embodiment.

[0056] Figure 11B is a cross-sectional view of a power semiconductor module 502 including a heat dissipation substrate for power semiconductors according to a second embodiment.

[0057] Figure 12 is a second cross-sectional view of a power semiconductor module 500 including a heat dissipation substrate for power semiconductors according to an embodiment.

[0058] Figure 13 FIG. 5 is a diagram showing a heat dissipation assembly 550 disposed on a semiconductor device chip of a circuit board 610 according to an embodiment.

[0059] Figure 14 1 is a circuit diagram of a power converter 1000 to which a power semiconductor module according to an embodiment is applied. DETAILED DESCRIPTION

[0060] Hereinafter, the invention according to the embodiment for solving the above-mentioned problems will be described in more detail with reference to the accompanying drawings.

[0061] The power semiconductor modules of the embodiments can be used in inverters or converters such as those for automobiles, computers, home appliances, solar power generation, and smart grids. In addition to eco-friendly vehicles, the power semiconductor modules of the embodiments can also be applied to various electrical and electronic devices such as chargers for electric vehicles, power supplies, and railways.

[0062] <Power semiconductor module including heat dissipation substrate>

[0063] Figure 2 is a cross-sectional view of a power semiconductor module 500 including a heat dissipation substrate for a power semiconductor according to an embodiment, and Figure 3 is a cross-sectional view of a power semiconductor device 100 provided on a power semiconductor module according to an embodiment.

[0064] Reference Figure 2 , a power semiconductor module 500 according to an embodiment may include a heat dissipation substrate 400 , a power semiconductor device 100 , and a wiring 130 a .

[0065] For example, the power semiconductor module 500 according to the embodiment may include a heat dissipation substrate 400, a power semiconductor device 100 disposed on the heat dissipation substrate 400, the power semiconductor device 100, and electrically connected wiring 130a. The power semiconductor device 100 may be bonded using a predetermined adhesive member 110, but is not limited thereto.

[0066] Figure 2 Although the second metal plate 422 is provided with a hollow structure HE capable of being filled with a working fluid, the present invention is not limited thereto. For example, a hollow structure HE capable of enclosing a working fluid may be formed in the third metal plate 423 .

[0067] In an embodiment, the power semiconductor device 100 may be disposed on the heat dissipation substrate 400 by soldering, sintering bonding, phase change bonding such as transient liquid phase bonding (TLP) bonding, ultrasonic bonding, or the like.

[0068] Brief reference Figure 3According to the embodiment, the power semiconductor device 100 may include a drain electrode 105, a semiconductor epitaxial layer 120, a source electrode 145s, and a gate electrode 165g. In addition, the epitaxial layer 120 may include silicon carbide (SiC), but is not limited thereto. In the form of a MOSFET, the source electrode 145s or the gate electrode 165g may include an Al-based metal, and the drain electrode 105 may include a Ti / Ni / Ag metal including a Ti layer, a Ni layer, or an Ag layer, or NiV / Ag, V (vanadium) / Ni / Ag, etc., but is not limited thereto.

[0069] Refer again Figure 2 The heat dissipation substrate 400 of the embodiment may include a single or multiple metal plates and an insulating substrate 410. For example, the heat dissipation substrate 400 may include a first metal plate 421, a second metal plate 422, an insulating substrate 410, and a third metal plate 423, but is not limited thereto.

[0070] The insulating substrate 410 can electrically insulate the second metal plate 422 from the third metal plate 423. The insulating substrate 410 may include a polycrystalline insulating substrate made of a ceramic material having high thermal conductivity. For example, the insulating substrate 410 may be one of AlN, Si3N4, or Al2O3, but is not limited thereto. Hereinafter, the insulating substrate 410 will be described as an example of a polycrystalline substrate made of ceramic, but is not limited thereto and may also include a single crystal substrate such as a sapphire substrate.

[0071] The first metal plate 421, the second metal plate 422, and the third metal plate 423 may include Cu-based metals, but are not limited thereto. For example, the first metal plate 421, the second metal plate 422, and the third metal plate 423 may include one or more of Al, Ni, Ag, Mg, or Zn.

[0072] One side of the second metal plate 422 may be in contact with the insulating substrate 410 , and heat may be dissipated to the other side. A heat dissipation device such as a heat sink may be provided near the lower side of the first metal plate 421 .

[0073] In an embodiment, the second metal plate 422 may include a single or multiple metal plates. For example, the second metal plate 422 may include a second-first metal plate 422a having a first through groove E1 and a first body B1. In addition, the second metal plate 422 may also include a second-second metal plate 422b having a second body B2 and a second through groove E2 (see Figure 7A ).

[0074] Refer again Figure 2, the second metal plate 422 is shown to include a second-first metal plate 422a and a second-second metal plate 422b, but is not limited thereto, and the second metal plate 422 may also be provided with a single second-first metal plate (422a).

[0075] In the second metal plate 422 , the first through-grooves E1 and the second through-grooves E2 may be three-dimensionally communicated to form a hollow structure HE, and may be filled with a working fluid (not shown) such as acetone, methanol, ethanol, or ultrasonic water.

[0076] Additionally, the first and second bodies B1 and B2 of the second metal plate 422 may include a porous structure capable of accommodating or absorbing a working fluid. For example, the first and second bodies B1 and B2 of the second metal plate 422 may be formed through a sintering process and may include a porous structure. Alternatively, the first and second bodies B1 and B2 of the second metal plate 422 may have grooves in the form of fine grooves on their sidewalls. Alternatively, the first and second bodies B1 and B2 of the second metal plate 422 may include a mesh-like porous structure.

[0077] According to this embodiment, since the heat generated by the power semiconductor device 100 is efficiently transferred to the second metal plate 422 of the heat dissipation substrate, the working fluid can be evaporated and the latent heat of evaporation can be absorbed. Thereafter, the working fluid can move toward the lower first metal plate 421 and condense into a liquid by releasing the latent heat of evaporation. Furthermore, the condensed working fluid can be absorbed into the porous structure of the second metal plate 422 and move toward the insulating substrate 410. Furthermore, in this embodiment, the power semiconductor device 100, serving as a heat source, can be placed below the heat dissipation substrate 400, and the condensed working fluid can be moved using gravity.

[0078] Next, the third metal plate 423 may include a plurality of circuit patterns (not shown) formed by a patterning process such as etching, and the circuit patterns may be electrically connected to the power semiconductor device 100. For example, Figure 2 As shown, one side of the circuit pattern of the third metal plate 423 can be electrically connected to the power semiconductor device 100 via the linear wiring 130a. Furthermore, the other side of the circuit pattern of the third metal plate 423 can be connected to an external connection terminal. The external connection terminal may include an input power source, a motor, or an inverter controller. When the third metal plate 423 is not patterned, the heat dissipation substrate 400 of this embodiment can be used as a heat dissipation component.

[0079] According to the power semiconductor module 500 including the heat dissipation substrate 400 for a power semiconductor according to the embodiment, since the hot pressing process is performed in a high-temperature, high-pressure vacuum environment, a heat dissipation substrate integrally equipped with the second metal plate 422 having the hollow structure HE capable of encapsulating a working fluid can be realized.

[0080] Therefore, according to the embodiment, the heat transfer path between the power semiconductor device 100 causing heat generation and the second metal plate 422 having the hollow structure HE can be shortened, thereby improving heat transfer efficiency. This has the technical effect of significantly improving heat dissipation performance by efficiently evaporating the fluid.

[0081] According to this embodiment, a heat dissipation substrate can be provided that is integrally provided with a second metal plate 422 having a hollow structure HE capable of encapsulating a working fluid within the heat dissipation substrate 400 itself, without intervening a separate adhesive layer. This allows heat to be transferred to the second metal plate 422 having the hollow structure HE without passing through the adhesive layer, which could cause thermal resistance. Consequently, the efficiency of heat transfer can be improved, and the working fluid can be efficiently vaporized, resulting in a technical effect of significantly improving heat dissipation performance.

[0082] Furthermore, according to embodiments, the interface between the second metal plate 422 having the hollow structure HE and the first metal plate 421, which are integrally bonded without an adhesive layer, can be indistinguishable. Furthermore, the material of the second metal plate 422 having the hollow structure HE and the material of the first metal plate 421, which is integrally formed below the hollow structure HE, can be the same, thereby addressing the difference in thermal expansion coefficient between the first metal plate 421 and the second metal plate 422. Consequently, embodiments can fundamentally prevent separation of the bonding interface or warping of the assembly, resulting in a significant improvement in the reliability of the power semiconductor module.

[0083] Hereinafter, while explaining the “manufacturing process of the heat dissipation substrate for power semiconductors”, the technical features of the “power semiconductor module 500 including the heat dissipation substrate” of the present application will be described in detail.

[0084] <Manufacturing Process of Heat Dissipation Substrate for Power Semiconductors>

[0085] Figure 4 FIG. 1 is a schematic process flow diagram of a manufacturing process of a heat dissipation substrate for a power semiconductor according to an embodiment.

[0086] The manufacturing process of the heat dissipation substrate for power semiconductors according to the embodiment may include (1) a pre-treatment process of the insulating substrate, (2) a sputtering process, (3) a pre-treatment process of the metal plate, (4) a lamination process of the insulating substrate and the metal plate, (5) a hot pressing process of the insulating substrate and the metal plate, (6) an etching process for the heat dissipation substrate, and (7) an inspection and cutting process for the heat dissipation substrate. The entire manufacturing process of the heat dissipation substrate for power semiconductors according to the embodiment may be controlled by a control unit (not shown) of a central server, and the central server may include a data storage unit (not shown).

[0087] Main manufacturing processes of a heat dissipation substrate for a power semiconductor according to the following embodiment will be described with reference to the accompanying drawings.

[0088] (1) Pretreatment process of insulating substrate

[0089] In the following, reference is made to Figure 5 Insulating substrate pretreatment process is described below. In an embodiment, before the lamination process of the insulating substrate and the metal plate, a "pretreatment process of the insulating substrate" may be performed in a substrate cleaning apparatus (not shown).

[0090] The pretreatment process of the insulating substrate may include: ① a loading step of the insulating substrate; ② a unique code UC marking process; ③ an insulating substrate cleaning process; ④ a thickness measurement process of the insulating substrate; and ⑤ a loading process of loading the insulating substrate into a material box.

[0091] ①Insulating substrate loading steps

[0092] First, if Figure 5 As shown, a predetermined insulating substrate base material SS can be prepared and loaded into a substrate cleaning device (not shown). The insulating substrate base material SS can be, but is not limited to, AlN, Si3N4, or Al2O3, and can also include a single crystal substrate such as a sapphire substrate. Irregularities R ranging in size from several μm to several hundred μm can exist on the surface of the insulating substrate 410, but are not limited to these.

[0093] ② Unique code UC marking process

[0094] According to embodiments, a unique code UC can be marked on the insulating substrate base material SS loaded into the substrate cleaning device. The unique code UC can then be read, and the read data can be transmitted and stored in a server's data storage device via wired or wireless transmission. This allows for accurate update and management of detailed information on individual heat dissipation substrates, including individual insulating substrates, in subsequent processes.

[0095] The insulating substrate base material SS may include an active area AA and a dummy area DA. A unique code UC may be marked on the dummy area DA of the insulating substrate base material SS. The unique code UC may include, but is not limited to, a digital matrix code DMC, a QR code, or a barcode. The unique code UC may be marked using, but is not limited to, laser marking technology.

[0096] In an embodiment, in the dummy area DA of the insulating substrate base material SS, a unique ID such as a serial number may be marked in addition to the unique code UC.

[0097] ③ Cleaning process of insulating substrate and ④ Thickness measurement process

[0098] Reference Figure 5 The insulating substrate base material SS may be subjected to a CDA (clean dry air) cleaning process CL. In the embodiment, after cleaning the insulating substrate base material SS, the thickness may be measured at nine points using the displacement sensor TM, but the present invention is not limited thereto.

[0099] ⑤Insulating substrate loading process

[0100] The insulating substrate base material can be loaded into a predetermined substrate cassette (not shown) and then transferred to a predetermined laminating device. In an embodiment, each substrate cassette can also be marked with a predetermined unique ID or unique code. Therefore, in the laminating process performed after the sputtering process, the unique ID of the substrate cassette can be read to accurately control the laminating and bonding processes according to the order used to manufacture the heat dissipation substrate.

[0101] (2) Sputtering process

[0102] As described above, the insulating substrates may be transferred to the sputtering device in a state of being loaded into the substrate magazine, and each insulating substrate may be unloaded and then mounted on the sputtering device to be subjected to a sputtering process.

[0103] In the following, reference is made to Figure 6 , the “sputtering process for insulating substrate” of the embodiment will be described.

[0104] Reference Figure 6 , a bonding metal layer 411 having a first thickness can be formed on one surface of the insulating substrate base material SS by sputtering. At this time, during the sputtering process, the unique code UC and the unique ID area can be protected by covering them with a spraying member (PS) or the like, thereby preventing sputtering from occurring on the unique code UC and the unique ID area.

[0105] For example, the insulating substrate base material SS is mounted on an anode electrode plate of a predetermined PVD apparatus and can be deposited in an inert atmosphere such as Ar gas at a temperature of about 100°C. to about The bonding metal layer 411 including Ti or TiW is formed to a first thickness of 1000 Å.

[0106] Next, a diffusion metal layer 412 may be formed by sputtering on the bonding metal layer 411. The diffusion metal layer 412 may be formed to a thickness greater than the first thickness of the bonding metal layer 411 by sputtering.

[0107] The diffusion metal layer 412 may have a melting point lower than the temperature of the hot pressing process to facilitate subsequent bonding. For example, the hot pressing temperature may be in the range of approximately 900° C. to 1100° C., and the diffusion metal layer 412 may be a material having excellent diffusion properties because the diffusion metal layer 412 has a melting point less than 900° C. For example, the diffusion metal layer 412 may be one or more of Al, Ag, Au, and Sn, but is not limited thereto.

[0108] Next, the insulating substrate base material SS on which the diffusion metal layer 412 has been deposited on one surface may be turned over, and then the bonding metal layer 411 and the diffusion metal layer 412 may be sequentially deposited on the opposite surface by sputtering.

[0109] According to the embodiment, there is a technical effect of reducing thermal resistance by thinning the first bonding metal layer 411 and the second bonding metal layer 421 , thereby improving the heat dissipation performance of the heat dissipation substrate.

[0110] In this embodiment, the thickness of the bonding metal layer 411 and the diffusion metal layer 412 of each individual insulating substrate 410 is measured after sputtering, and the thickness data of each unique code UC is transmitted to the server for update management. For example, in this embodiment, the thickness of the bonding metal layer 411 and the diffusion metal layer 412 can be measured by measuring the sheet resistance of the individual insulating substrate 410, but the present invention is not limited to this. The individual insulating substrates 410 whose thicknesses have been measured for the bonding metal layer 411 and the diffusion metal layer 412 can be reloaded into the substrate magazine and then transferred to the lamination device.

[0111] (3) Pretreatment process of metal plate

[0112] In the following, reference will be made to Figure 7A and Figure 7B The pre-treatment process of the metal plate according to the embodiment is described. The metal plate may include a single metal plate or a plurality of metal plates. For example, the metal plate may include a first metal plate 421, a second metal plate 422, and a third metal plate 423, but is not limited thereto.

[0113] The metal plate may be a metal plate having excellent electrical and thermal conductivity. For example, the metal plate may be a Cu plate or a Cu alloy plate, but is not limited thereto. For example, the metal plate may include any one or more of Al, Ni, Ag, Mg, and Zn. The metal plate may also be referred to as a metal substrate. In an embodiment, the first metal plate 421, the second metal plate 422, and the third metal plate 423 may be marked with a predetermined unique ID or unique code.

[0114] The pre-processing process of the metal plate may include a cleaning process and a thickness measurement process of the metal plate.

[0115] The metal plates can be divided into multiple groups according to their thickness. For example, the metal plates can be divided into a first metal plate 421, a second metal plate 422, and a third metal plate 423 according to their thickness, but the present invention is not limited thereto. The third metal plate 423 can be thicker than the first metal plate 421 and the second metal plate 422, but the present invention is not limited thereto.

[0116] The first metal plate 421 may have a first thickness T1. For example, the first metal plate 421 may have a first thickness T1 of 100 μm to 300 μm.

[0117] In addition, the second metal plate 422 includes a second-first metal plate 422a having a second-first thickness T2a and a second-second metal plate 422b having a second-second thickness T2b.

[0118] For example, the second-first metal plate 422a may have a second-first thickness T2a of 100 μm to 300 μm, and the second-second metal plate 422b may have a second-second thickness T2b of 100 μm to 300 μm.

[0119] The second-first metal plate 422a may include a plurality of first through-grooves E1 arranged in a first direction (X). Furthermore, the second-second metal plate 422b may include a plurality of second through-grooves E2 arranged in a second direction (Y) perpendicular to the first direction (X). During a subsequent hot pressing process, the first through-grooves E1 and the second through-grooves E2 may be three-dimensionally connected to form a hollow structure HE.

[0120] The second-first metal plate 422a may include a first body B1 between a plurality of spaced-apart first through grooves E1, and the second-second metal plate 422b may include a second body B2 between a plurality of spaced-apart second through grooves E2. The second body B2 of the second-second metal plate 421b and the first body B1 of the second-first metal plate 421a may have a porous structure capable of inducing capillary action.

[0121] For example, the first body B1 of the second-first metal plate 422a and the second body B2 of the second-second metal plate 422b may include a porous structure that can accommodate or absorb a working fluid. For example, the first body B1 and the second body B2 of the second metal plate 422 may be formed by a sintering process and may include a porous structure. Alternatively, the first body B1 and the second body B2 of the second metal plate 422 may have grooves in the form of fine grooves on their side walls. Alternatively, the first body B1 and the second body B2 of the second metal plate 422 may include a mesh-like porous structure. At the same time, in an embodiment, the power semiconductor device 100 as a heat source may be placed below the heat dissipation substrate 400, and the condensed working fluid may be moved by gravity.

[0122] In the field of conventional heat dissipation substrates, no attempt has been made to realize a porous structure in the heat dissipation substrate itself, and even in internal research, when a porous structure is provided in the heat dissipation substrate itself by hot pressing, buckling of the pores occurs, so that there are significant technical problems. On the other hand, according to an embodiment, buckling of the pores can be prevented by forming a porous structure in the second metal plate 422 through a sintering process. In addition, according to an embodiment, buckling of the pores can be prevented by providing a groove-shaped groove in the side wall. In addition, according to this embodiment, there is a technical effect of preventing buckling of the pores during hot pressing by realizing a cross-shaped hole.

[0123] In addition, according to an embodiment, the hot pressing process can be performed after impregnating a predetermined fluid into the porous structure provided in the second metal plate before the hot pressing process. Therefore, there is a special technical effect of preventing the pores from buckling by maintaining the porous structure through the vapor pressure of the fluid.

[0124] Next, refer to Figure 7B The third metal plate 423 may have a third thickness T3. For example, the third metal plate 423 may have a third thickness T3 of 600 μm to 900 μm.

[0125] In an embodiment, the first metal plate 421, the second-first metal plate 422a, the second-second metal plate 422b, and the third metal plate 423 are marked with a unique ID or a unique code. At this time, metal plates with corresponding thicknesses or through grooves can be loaded into the first metal cassette, the second-first metal cassette, the second-second metal cassette, and the third metal cassette, respectively, and then transferred to a predetermined lamination device. In one embodiment, each of the first metal cassette, the second-first metal cassette, the second-second metal cassette, and the third metal cassette can be marked with a predetermined unique ID or unique code.

[0126] According to one embodiment, metal sheets can be sorted and loaded into a first metal magazine, a second-first metal magazine, a second-second metal magazine, or a third metal magazine based on thickness, presence of through-grooves, or the orientation of through-grooves. The thickness of the metal magazines, through-grooves information, and sorting and loading information can be stored and managed on a host server.

[0127] Furthermore, the unique information of each metal sheet can be accurately updated and managed with the information of the loaded metal magazine.

[0128] Therefore, in a subsequent stacking process, a hot pressing process may be performed by accurately matching a stacking order by reading the unique ID of the first metal cartridge, the second-first metal cartridge, the second-second metal cartridge, or the third metal cartridge.

[0129] (4) Lamination process of insulating substrate and metal plate

[0130] Next, refer to Figure 8 The step of laminating the insulating substrate and the metal plate will be described.

[0131] Figure 8 This is a conceptual diagram of laminating an insulating substrate and a metal plate in an embodiment.

[0132] A first stack ST1 can be prepared (see Figure 8 ), the first stack ST1 will be the heat dissipation substrate 400 of the embodiment (see Figure 10 ).

[0133] For example, refer to Figure 8 , the first metal plate 421, the second-second metal plate 422b, and the second-first metal plate 422a may be sequentially stacked on the first carbon spacer (not shown). The insulating substrate 410, the third metal plate 423, and the second carbon spacer (not shown) may be sequentially stacked. In an embodiment, graphite (not shown) may be stacked after performing 10 stacking groups, but the method is not limited thereto.

[0134] According to an example, the stacked unit group may be placed in a hot press while maintaining their alignment and undergo a hot pressing process, thereby realizing a high-quality heat dissipation substrate having a hollow structure HE without distortion of the stacked units.

[0135] Furthermore, according to embodiments, in addition to being able to place the stacked stack into the hot press while maintaining alignment, carbon spacers can be placed at the top and bottom to offset pressure deviations, thereby maintaining uniform pressure distribution. This has the technical effect of reducing the risk of cracks that may occur in the ceramic.

[0136] (5) Hot pressing process of insulating substrate and metal plate

[0137] Next, refer to Figure 9 The thermocompression bonding step according to the embodiment will be described.

[0138] Reference Figure 9 The stacked group can be placed in a hot pressing device (not shown) and hot pressed under vacuum to form a Figure 10 A heat dissipation substrate 400 for a power semiconductor module according to an embodiment is shown.

[0139] The temperature of the hot pressing process may be about 900° C. to about 1100° C. Preferably, the temperature of the hot pressing process may be about 950° C. to about 1000° C., but is not limited thereto. The vacuum degree of the hot pressing process may be 1.0×10 -1 The pressure of the hot pressing process may be about 10 MPa to about 100 MPa, but is not limited thereto.

[0140] In the prior art, various heat dissipation components and heat dissipation modules such as heat sinks, heat dissipation plates, heat pipes, and vapor chambers are used to solve the heating problem of electronic devices such as power semiconductor modules.

[0141] However, in the prior art, when a separately manufactured vapor chamber heat sink is bonded to a base or auxiliary substrate using an adhesive, the heat transfer path from the vapor emitted by the electronic device to the vapor chamber heat sink becomes longer. Furthermore, the separate adhesive layer inserted between the vapor chamber heat sink and the base or auxiliary substrate creates thermal resistance and reduces heat transfer efficiency, preventing the working fluid from evaporating properly and thus degrading heat dissipation performance.

[0142] Additionally, differences in thermal expansion coefficients between the individually bonded components and the heat dissipation substrate material may cause delamination of the bonding interface or warping of the components, which can lead to failure of the power semiconductor module.

[0143] Because the vapor chamber heat sink is bonded to the heat dissipation substrate via adhesive, the heat transfer path from the heat-generating electronic device to the vapor chamber heat sink becomes longer. Furthermore, the presence of a separate adhesive layer between the vapor chamber heat sink and the heat dissipation substrate reduces heat transfer efficiency due to thermal resistance. Therefore, one of the technical objectives of this embodiment is to address the issue of reduced heat dissipation performance of the working fluid vapor chamber heat sink.

[0144] Furthermore, since the heat dissipation substrate and the heat dissipation assembly are bonded together via an adhesive layer, differences in the thermal expansion coefficients of the bonded components can cause delamination at the bonded interface or warping of the assembly. Therefore, one of the technical objectives of the embodiments is to address the problem of power semiconductor module failures caused by differences in thermal expansion coefficients.

[0145] Meanwhile, in the field of conventional heat dissipation substrate technology, heat dissipation issues are addressed by combining or placing various heat dissipation components, such as heat sinks, heat dissipation plates, heat pipes, and vapor chambers, on the heat dissipation substrate. However, there has been no consideration or research into forming heat dissipation components integrally with the metal plate constituting the heat dissipation substrate.

[0146] Specifically, when direct bonding between Cu metal plates occurs, the oxide layer formed on the Cu surface prevents proper Cu-to-Cu bonding. Furthermore, the presence of the oxide layer at the bonding interface causes high electrical and thermal resistance, which degrades the thermal and electrical properties of the heat dissipation substrate.

[0147] Meanwhile, in the conventional heat dissipation substrate technology field, there has been no attempt to form a metal plate having a hollow structure integrally with a heat dissipation substrate. In addition, during internal research, there were significant technical difficulties in realizing a metal plate having a hollow structure integrally with a heat dissipation substrate.

[0148] On the other hand, according to the power semiconductor module 500 according to the embodiment, since the hot pressing process is performed in a high-temperature and high-pressure vacuum environment, the heat dissipation substrate 400 can be integrally provided with the second metal plate 422 having the hollow structure HE capable of encapsulating the working fluid.

[0149] Therefore, according to the embodiment, the heat transfer path between the power semiconductor device 100 as a heat source and the second metal plate 422 having the hollow structure HE can be significantly shortened, thereby improving the heat transfer efficiency. Therefore, there is a technical effect that the working fluid can be efficiently evaporated, thereby significantly improving the heat dissipation performance.

[0150] In addition, according to the embodiment, since the heat dissipation substrate 400 can be integrally implemented with the second metal plate 422 having the hollow structure HE capable of encapsulating the working fluid, heat can be transferred to the second metal plate 422 having the hollow structure HE without passing through the adhesive layer. Therefore, the heat transfer efficiency can be improved, and the working fluid can be effectively vaporized, resulting in a technical effect of significantly improving the heat dissipation performance.

[0151] Furthermore, the heat dissipation substrate 400 according to the embodiment includes a second metal plate 422 having a hollow structure HE and a first metal plate integrally bonded to the underside of the second metal plate 422, such that the interface between the first metal plate 421 and the second metal plate 422 is substantially indistinguishable. Furthermore, the material of the second metal plate 422 having the hollow structure HE is the same as that of the first metal plate 421, which is integrally formed below the second metal plate 422. Thus, the difference in thermal expansion coefficient between the first metal plate 421 and the second metal plate 422 is resolved, resulting in a significant technical advantage in that warping of the glass or bonding components at the bonding interface is fundamentally prevented, significantly improving the reliability of the power semiconductor module.

[0152] (6) Inspection, etching and cutting processes of heat dissipation substrates, etc.

[0153] The following describes the inspection, etching, and cutting processes for the heat dissipation substrate. The cleaning, inspection, and etching processes can be performed on each heat dissipation substrate manufactured through the thermocompression bonding process. For example, the heat dissipation substrate 400 of the embodiment manufactured through the thermocompression bonding process can be subjected to brush cleaning, water washing, and drying processes, but the processes are not limited thereto.

[0154] In addition, in an embodiment, ultrasonic inspection of the bonding interface can be performed on the heat dissipation substrate manufactured by hot pressing. For example, according to an embodiment, the interface thickness, gaps and cracks of the bonding interface of each heat dissipation substrate can be inspected using ultrasonic inspection equipment.

[0155] According to embodiments, the unique code UC formed in the dummy area of each heat sink substrate can be exposed by partially removing the metal plate in the dummy area after the thermocompression bonding process. According to embodiments, this has the particular technical advantage of being able to accurately update and manage inspection information regarding the interface thickness, presence of voids, and cracks at the bonding interface of each heat sink substrate after the thermocompression bonding process.

[0156] Afterwards, an etching process can be performed on the heat dissipation substrate determined to be a good product during the inspection process to form a circuit pattern. For example, regarding the heat dissipation substrate 400 in an embodiment in which a hot pressing process is performed, a circuit pattern can be formed on the third metal plate 423 through an etching process. For example, the third metal plate 423 can include a plurality of circuit patterns (not shown) formed through a patterning process such as etching, and the circuit patterns can be electrically connected to the power semiconductor device 100.

[0157] For example, Figure 11AAs shown, one side of the circuit pattern of the third metal plate 423 can be electrically connected to the power semiconductor device 100 through a wiring 130a such as a wire. In addition, the other side of the circuit pattern of the third metal plate 423 can be connected to an external connection terminal. The external connection terminal may include an input power supply, a motor, or an inverter controller.

[0158] The embodiment has a special technical effect in that etching information (etchant, etching process conditions, etc.) of each heat dissipating substrate can be accurately updated and managed after the hot pressing process.

[0159] If the etching process for forming the circuit pattern is not performed, the heat dissipation substrate can be used as a heat dissipation component. This can be the same as the heat dissipation substrate process after the etching process.

[0160] Next, the laser scribing process, inspection process, and cutting process for the heat dissipation substrate will be described. For example, an etching inspection can be performed on a heat dissipation substrate that has completed the etching process. For heat dissipation substrates with good etching tests, a unique code UC can be marked on the metal plate. For example, when a heat dissipation substrate includes 9 snap regions, unique information UC can be marked on each snap of the first metal plate 421 that does not have a circuit pattern. The unique information UC marking on each snap region of the first metal plate 421 can be performed after laser scribing.

[0161] Next, a laser scribing process and a breaking process may be performed. In an embodiment, an inspection process may be performed after the laser scribing process and before the breaking process. The inspection process may include an ultrasonic test (SAT), which uses ultrasonic waves to perform a secondary inspection of gaps or cracks at the bonding interface. In addition, the inspection process after the laser scribing process may include a process for parsing surface information such as surface roughness, surface pinhole inspection, protrusion inspection, foreign matter inspection, etc. through an automatic appearance inspection process. The special technical effect of the embodiment is that the secondary bonding interface inspection information and automatic appearance inspection information of a single heat dissipation substrate can be accurately updated and managed after the etching process.

[0162] After that, the final good products can be cut and separated to produce Figure 10 The single heat dissipation substrate 400 shown. Figure 10The heat dissipation substrate 400 of the illustrated embodiment is delivered with a unique code UC on the bottom of the first metal plate 421. Therefore, according to this embodiment, the unique information that can confirm all the process history information of the product from the initial warehousing stage can be perfectly matched with the final product and delivered to the customer, and the customer can also check the product through the unique information. The unique information can be used to accurately grasp the quality, production examples, etc. Moreover, after-sales service can be handled quickly and accurately when needed. In addition, simply marking the product information on the heat dissipation substrate of the final product cannot perfectly match and manage information such as the thickness information of the insulating substrate, the thickness information of the metal plate, and the bonding interface information of the product.

[0163] <Power Converter Including Heat Dissipation Substrate>

[0164] Figure 11A is a first cross-sectional view of a power semiconductor module 500 including a heat dissipation substrate according to an embodiment, and Figure 12 is a second cross-sectional view of a power semiconductor module 500 including a heat dissipation substrate for power semiconductors according to an embodiment.

[0165] As described above, a good heat dissipation substrate having a circuit pattern formed thereon can be manufactured by a snap-on cutting and separation process. Figure 10 A single heat dissipation substrate 400 is shown.

[0166] Next, refer to Figure 12 A working fluid inlet TH may be formed on one side of the second metal plate 422 of the heat dissipation substrate 400 of the power semiconductor module 500 according to the embodiment, and a working fluid (not shown) may be injected into the hollow structure HE, and the fluid inlet TH may be closed. The working fluid may be acetone, methanol, ethanol, or ultrapure water (DI water), but is not limited thereto.

[0167] According to this embodiment, since the heat generated by the power semiconductor device 100 can be effectively transferred to the second metal plate 422 of the heat dissipation substrate, the working fluid can be evaporated and the latent heat of evaporation can be absorbed. The working fluid then moves toward the lower first metal plate 421 and condenses, condensing into a liquid while releasing the latent heat of evaporation. The condensed working fluid can be absorbed into the porous structure of the second metal plate 422 and move toward the insulating substrate 410. In one embodiment, the power semiconductor device 100, which serves as a heat source, can be placed below the heat dissipation substrate 400, and the condensed working fluid can be moved using gravity.

[0168] Next, Figure 11Bis a cross-sectional view of a power semiconductor module 502 including a heat dissipation substrate according to a second embodiment. The second embodiment may adopt technical features of the previously described embodiments, and the following description will focus on the main features of the second embodiment.

[0169] Reference Figure 11B The power semiconductor module 502 according to the second embodiment may include a heat dissipation substrate 400 , a power semiconductor device 100 disposed on the heat dissipation substrate 400 , the power semiconductor device 100 , and a wiring 130 a electrically connected to the power semiconductor device 100 .

[0170] The power semiconductor module 502 according to the second embodiment may include a first metal plate 421 , an insulating substrate 410 , a second metal plate 422 , and a third metal plate 423 , but is not limited thereto.

[0171] In particular, in the second embodiment, a hollow structure HE capable of being filled with a working fluid may be provided between the power semiconductor device 100 and the insulating substrate 410 .

[0172] For example, the second metal plate 422 of the second embodiment may be disposed between the insulating substrate 410 and the third metal plate 423 and may have a hollow structure HE. In the second embodiment, the power semiconductor device 100 may be disposed on the third metal plate 423, but is not limited thereto.

[0173] The second metal plate 422 of the second embodiment may include a single or multiple metal plates. For example, the second metal plate 422 may include a second-first metal plate 422a having a first through-groove E1 and a first body B1. Alternatively, the second metal plate 422 may include a second-second metal plate 422b having a second body B2 and a second through-groove E2. The first groove E1 and the second groove E2 of the second metal plate 422 may form a three-dimensional hollow structure, which may be filled with operating acetone, methanol, ethanol, ultrapure water, or the like.

[0174] Additionally, the first and second bodies B1 and B2 of the second metal plate 422 may include a porous structure capable of accommodating or absorbing a working fluid. For example, the first and second bodies B1 and B2 of the second metal plate 422 may be formed through a sintering process and may include a porous structure. Alternatively, the first and second bodies B1 and B2 of the second metal plate 422 may have grooves in the form of fine grooves on their sidewalls. Alternatively, the first and second bodies B1 and B2 of the second metal plate 422 may include a mesh-like porous structure.

[0175] Furthermore, in the conventional heat dissipation substrate technology field, heat dissipation issues are addressed by combining or placing various heat dissipation components, such as heat sinks, heat dissipation plates, heat pipes, and vapor chambers, on the heat dissipation substrate or the metal constituting the heat dissipation substrate. There has been no consideration or research into forming heat dissipation components integrally with the metal plate itself.

[0176] The heat dissipation substrate includes an insulating substrate, an upper metal plate and a lower metal plate disposed above and below the insulating substrate, respectively. The upper metal plate serves as a wiring board on which a circuit pattern is formed by etching in addition to the heat dissipation function.

[0177] Therefore, in the conventional heat dissipation substrate technology field, there has been no attempt to integrally form a metal plate having a hollow structure with a heat dissipation substrate, and in particular, this is difficult to consider because the hollow structure may be damaged by etching the "upper metal plate" on which the circuit pattern is formed.

[0178] Furthermore, even considering the hollow structure of the upper metal plate, where the insulating substrate is exposed by etching and the circuit pattern is formed, it is difficult to form a precise circuit pattern on the upper metal plate. Therefore, as a result of considerable internal research, achieving an upper metal plate with a hollow structure was a very difficult technical challenge.

[0179] On the other hand, according to the second embodiment, a second metal plate 422 having a grid-like hollow structure can be placed on the insulating substrate 410 and hot-pressed in a high-temperature, high-pressure, vacuum environment. As the process progresses, the heat dissipation substrate, comprising the second metal plate 422 having a hollow structure capable of encapsulating a working fluid, can be integrated with the upper metal plate.

[0180] For example, according to the second embodiment, the hollow structure is not placed in the first region to be removed by etching, but is placed in the second region not to be removed by etching. After the metal plates 422 are prepared and stacked, a hot pressing process can be performed in a high temperature, high pressure, vacuum environment.

[0181] For example, Figure 11B 4 is a cross-sectional view of the second region of the second metal plate 422 where the hollow structure HE is provided.

[0182] Therefore, according to the second embodiment, although the hollow structure is provided in the second region of the upper second metal plate 422 where the circuit pattern is formed, the subsequent etching process is performed in the first region where the hollow structure is not provided. As the etching proceeds, the insulating substrate is exposed, enabling the circuit pattern to be formed. Thus, according to the second embodiment, a special technical effect is achieved by resolving the technical contradiction of damaging the hollow structure by etching when the hollow structure is provided in the "upper metal plate."

[0183] According to the second embodiment, since the heat generated by the power semiconductor device 100 can be efficiently transferred to the second metal plate 422, the working fluid evaporates through the hollow structure, absorbing the latent heat of evaporation. The working fluid then moves toward the insulating substrate 410 and the first metal plate 421, condensing into a liquid while releasing the latent heat of evaporation. Furthermore, the condensed working fluid is absorbed into the porous structure of the second metal plate 422 and moves toward the third metal plate 423.

[0184] According to the power semiconductor module 502 including the heat dissipation substrate 400 for power semiconductors according to the second embodiment, since the hot pressing process is performed in a vacuum environment of high temperature and high pressure, the heat dissipation substrate 400 can be implemented as an integral part with the second metal plate 422 having a hollow structure capable of encapsulating a working fluid.

[0185] Therefore, according to the second embodiment, the heat transfer path between the power semiconductor device 100 and the second metal plate 422 having a hollow structure, which causes heat generation, can be significantly shortened, thereby improving heat transfer efficiency. This has the technical effect of significantly improving heat dissipation performance by efficiently vaporizing the fluid.

[0186] In particular, in the second embodiment, a second metal plate 422 having a hollow structure in which a working fluid can be sealed is arranged between the power semiconductor device 100 and the insulating substrate 410, which can significantly shorten the heat transfer path between the power semiconductor device 100 and the second metal plate 422 having a hollow structure, thereby significantly improving the heat dissipation performance.

[0187] Furthermore, according to the second embodiment, the heat dissipation substrate can be integrally provided with the second metal plate 422 having a hollow structure capable of encapsulating the working fluid within the heat dissipation substrate 400 itself, without the need for a separate adhesive layer. Consequently, heat can be transferred to the second metal plate 422 having a hollow structure via the third metal plate 423 without passing through the adhesive layer, which could cause thermal resistance. This improves heat transfer efficiency, significantly improving heat dissipation performance.

[0188] In addition, the heat dissipation substrate 400 according to the second embodiment includes a second metal plate 422 having a hollow structure (HE) and a third metal plate 423 integrally bonded to the underside of the second metal plate 422, such that the interface between the third metal plate 423 and the second metal plate 422 is substantially indistinguishable. In addition, the material of the second metal plate 422 having a hollow structure (HE) is the same as the material of the third metal plate 423 integrally formed below the second metal plate 422. Therefore, the difference in thermal expansion coefficient between the third metal plate 423 and the second metal plate 422 is resolved, resulting in a special technical effect in that the reliability of the power semiconductor module can be significantly improved by fundamentally preventing delamination of the bonding interface or warping of the bonded assembly.

[0189] Next, Figure 13 is a diagram illustrating a heat dissipation assembly 550 according to an embodiment provided on a semiconductor device chip of a circuit board 610 .

[0190] For example, the pillars 620 may be spaced apart and placed on the circuit board 610, and the semiconductor device chips may be placed within the pillars 620 of the circuit board 610. The semiconductor device chips may be Si semiconductor devices or SiC semiconductor devices, but are not limited thereto. The pillars 620 may have excellent heat transfer performance and may be made of an electrically insulating material, but are not limited thereto.

[0191] Reference Figure 13 The heat dissipation assembly 550 according to the embodiment may be bonded to the semiconductor device chip by a predetermined adhesive member (not shown), but is not limited thereto. For example, the heat dissipation assembly 550 is connected to the semiconductor device chip by soldering, sintering bonding, transient liquid phase (TLP) bonding, ultrasonic bonding, etc.

[0192] The heat dissipation assembly 550 of the embodiment may include a single or multiple metal plates and an insulating substrate 510. For example, the heat dissipation assembly 550 may include a first metal plate 521, a second metal plate 522, an insulating substrate 510, and a third metal plate 523, but is not limited thereto.

[0193] The insulating substrate 510 can electrically insulate the second metal plate 522 from the third metal plate 523. The insulating substrate 510 may include a polycrystalline insulating substrate made of a ceramic material having high thermal conductivity. For example, the insulating substrate 510 may be one of AlN, Si3N4, and Al2O3. Hereinafter, the insulating substrate 510 will be described as an example of a polycrystalline substrate made of ceramic, but is not limited thereto and may also include a single crystal substrate such as a sapphire substrate.

[0194] The first metal plate 521, the second metal plate 522, and the third metal plate 523 may include Cu-based metals, but are not limited thereto. For example, the first metal plate 521, the second metal plate 522, and the third metal plate 523 may include one or more of Al, Ni, Ag, Mg, and Zn.

[0195] One side of the second metal plate 522 is in contact with the insulating substrate 510 , and heat can be dissipated to the other side.

[0196] In an embodiment, the second metal plate 522 may include a single or multiple metal plates. For example, the second metal plate 522 may include a second-first metal plate 522a having a first through groove E1 and a second body B2. Alternatively, the second metal plate 522 may further include a second-second metal plate 522b having a first body B1 and a second through groove E2.

[0197] The second metal plate 522 is illustrated as including a second-first metal plate 522 a and a second-second metal plate 522 b , but is not limited thereto and may include a single metal plate.

[0198] In the second metal plate 522 , the first through-grooves E1 and the second through-grooves E2 may be three-dimensionally connected to form a hollow structure HE, which may be filled with a working fluid (not shown) such as acetone, methanol, ethanol, or ultrasonic water.

[0199] Additionally, the first and second bodies B1 and B2 of the second metal plate 522 may include a porous structure capable of accommodating or absorbing a working fluid. For example, the first and second bodies B1 and B2 of the second metal plate 522 may be formed through a sintering process and may include a porous structure. Alternatively, the first and second bodies B1 and B2 of the second metal plate 522 may have grooves in the form of fine grooves on their sidewalls. Alternatively, the first and second bodies B1 and B2 of the second metal plate 522 may include a mesh-like porous structure.

[0200] According to this embodiment, since the heat generated by the semiconductor device chip is efficiently transferred to the second metal plate 522 of the heat dissipation substrate, the working fluid is evaporated and the latent heat of evaporation is absorbed. The working fluid can then move toward the upper third metal plate 523 and condense into liquid while releasing the latent heat of evaporation. The condensed working fluid can then be absorbed into the porous structure of the second metal plate 522 and move toward the first metal plate 521.

[0201] Next, the third metal plate 523 may be in the form of a heat sink. For example, the third metal plate 523 may include a plurality of heat dissipation fins formed by a patterning process such as etching, but is not limited thereto.

[0202] In addition, in this embodiment, the third metal plate 523 may include a second hollow structure (not shown) corresponding to the hollow structure HE. For example, the third metal plate 523 may include a third-first metal plate (not shown) and a third-second metal plate (not shown) sequentially arranged from the insulating substrate 510.

[0203] In addition, the third metal plate 523 includes a third through groove (not shown) and a fourth through groove provided in the third-first metal plate (not shown) and the third-second metal plate (not shown). The third through groove (not shown) and the fourth through groove (not shown) can be three-dimensionally connected to form a second hollow structure, and the second hollow structure can be filled with a working fluid (not shown) such as acetone, methanol, ethanol, or ultrasonic water.

[0204] The heat dissipation assembly 550 according to the embodiment can be subjected to a hot pressing process in a high-temperature, high-pressure vacuum environment. Therefore, the second metal plate 522 having the hollow structure HE capable of sealing the working fluid in the heat dissipation assembly 550 itself can be integrally realized.

[0205] In addition, according to this embodiment, since the evaporation of the working fluid is made more efficient, the heat transfer path between the semiconductor device causing heat generation and the second metal plate 522 having the hollow structure HE can be shortened, and the heat transfer efficiency can be improved, thereby having the technical effect of significantly improving the heat dissipation performance.

[0206] Furthermore, depending on the embodiment, heat dissipation assembly 550 can be integrally provided with second metal plate 522, which itself has a hollow structure capable of encapsulating a working fluid, without requiring the interposition of a separate adhesive layer. Consequently, heat can be transferred to second metal plate 522, which has a hollow structure, without passing through the adhesive layer, which could cause thermal resistance. This improves heat transfer efficiency and significantly enhances heat dissipation performance.

[0207] In addition, the heat dissipation assembly 550 according to the embodiment includes a second metal plate 522 having a hollow structure (HE) and a first metal plate 521 integrally bonded to the underside of the second metal plate 522, so that the interface between the first metal plate 521 and the second metal plate 522 can be substantially indistinguishable. In addition, the material of the second metal plate 522 having a hollow structure (HE) is the same as the material of the first metal plate 521 integrally formed below the second metal plate 522. Therefore, the difference in thermal expansion coefficient between the first metal plate 521 and the second metal plate 522 is resolved, and its special technical effect is that the reliability of the power semiconductor module can be significantly improved by fundamentally preventing delamination of the bonding interface or warping of the bonding assembly.

[0208] Next, Figure 14is an exemplary circuit diagram of a power converter 1000 to which a power semiconductor module according to an embodiment is applied.

[0209] In the embodiments, the power semiconductor device is described as an automotive inverter for driving a motor, but the power semiconductor device in the embodiments can be applied to inverters or converters in the various technical fields described above. Here, vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (EVs), and fuel cell electric vehicles (PCEVs).

[0210] The power converter 1000 according to the embodiment can receive DC power from a battery or a fuel cell and convert it into AC power, and supply the AC power to a predetermined load. For example, the power converter 1000 according to the embodiment may include an inverter and convert the DC power from the battery. For example, the power converter 1000 can receive input, convert it into three-phase AC power, and supply it to a motor (M), which can provide power to an electric vehicle, a fuel cell vehicle, etc.

[0211] The power converter 1000 according to the embodiment may include a power semiconductor device 100. The power semiconductor device 100 may be a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), but is not limited thereto, and may include an IGBT (Insulated Gate Bipolar Transistor).

[0212] For example, the power converter 1000 may include a plurality of power semiconductor devices (100a, 100b, 100c, 100d, 100e, 100f) and a plurality of diodes (not shown). Each of the plurality of diodes may be embedded in each of the power semiconductor devices 100a, 100b, 100c, 100d, 100e, and 100f in the form of an internal diode, but is not limited thereto and may be provided separately.

[0213] The embodiment can convert DC power into AC power by controlling the on-off of a plurality of power semiconductor devices 100a to 100f. For example, the power converter 1000 according to the embodiment can supply positive polarity power by turning on the first power semiconductor device 100a and turning off the second power semiconductor device 100b during a first period of a cycle to operate the motor M. In addition, the power converter 1000 can supply negative polarity power to the motor M by turning off the first power semiconductor device 100a and turning on the second power semiconductor device 100b during a second period of a cycle.

[0214] In an embodiment, a group of power semiconductor devices arranged in series on the high-voltage line and the low-voltage line on the input side may be referred to as an arm. For example, the first power semiconductor device 100a and the second power semiconductor device 100b form a first arm 12a, the third power semiconductor device 100c and the fourth power semiconductor device 100d form a second arm 12b, and the fifth power semiconductor device 100e and the sixth power semiconductor device 100f may form a third arm 12c.

[0215] You can Figure 14 The multiple power semiconductor devices 100a to 100f shown are packaged as a single power semiconductor module, or the power semiconductor devices that make up each arm can be packaged as a single power semiconductor module. In an arm, the upper power semiconductor device and the lower power semiconductor device can be controlled so that they are not turned on at the same time. For example, in the first arm, the first power semiconductor device 100a and the second power semiconductor device 100b can be turned on and off alternately instead of being turned on simultaneously.

[0216] The power semiconductor device 100 of the embodiment may be a silicon carbide (SiC) power semiconductor device, may operate in a high temperature and high voltage environment, and may have a high switching speed and low switching loss.

[0217] Although the present invention has been described above with reference to embodiments, those skilled in the art will appreciate that the present invention may be modified and varied in various ways without departing from the spirit and scope of the invention as set forth in the appended patent claims.

Claims

1. A heat dissipation substrate for a power semiconductor module, the heat dissipation substrate comprising: insulating substrate; a lower metal plate, the lower metal plate being arranged below the insulating substrate; as well as an upper metal plate, the upper metal plate being disposed on the insulating substrate, Wherein, the lower metal plate includes a hollow structure.

2. The heat dissipation substrate according to claim 1, wherein The lower metal plate includes a second metal plate joined to a bottom of the insulating substrate and a first metal plate joined to a bottom of the second metal plate.

3. The heat dissipation substrate according to claim 2, wherein The second metal plate includes a second-first metal plate having a plurality of first through grooves arranged in a first direction and joined to the insulating substrate.

4. The heat dissipation substrate according to claim 3, wherein The second metal plate includes a second-second metal plate having a plurality of second through grooves arranged in a second direction perpendicular to the first direction and joined to a bottom portion of the second-first metal plate.

5. The heat dissipation substrate according to claim 4, wherein The second-first metal plate includes a first body between a plurality of spaced-apart first through-grooves, and The second-second metal plate includes a second body between a plurality of spaced-apart second through grooves. The heat dissipation substrate according to claim 2 , wherein: The upper metal plate includes a third metal plate bonded to the insulating substrate, and The third metal plate is thicker than the first metal plate or the second metal plate.

7. The heat dissipation substrate according to claim 6, wherein The third metal plate includes a circuit pattern on a surface thereof.

8. The heat dissipation substrate according to claim 2, wherein The second metal plate is directly bonded to the bottom of the insulating substrate without an adhesive layer, and Wherein, the first metal plate is directly bonded to the bottom of the second metal plate without an adhesive layer.

9. A power semiconductor module, comprising: The heat dissipation substrate for a power semiconductor module according to any one of claims 1 to 8; as well as A power semiconductor device is provided on the upper metal plate. 10 . A power converter comprising the power semiconductor module according to claim 9 .

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