Metal and ceramic substrate integration method, substrate structure and composite substrate

Abstract

The invention provides an integration method of a metal substrate and a ceramic substrate, a substrate structure and a composite substrate. The integration method of the metal and the ceramic substrate comprises the following specific steps: carrying out surface treatment on a ceramic substrate raw material and cutting the ceramic substrate raw material into an initial ceramic substrate according to a preset specification; performing surface treatment on a metal sheet raw material and cutting the metal sheet raw material into initial metal sheets according to the preset specification; the N initial ceramic substrates and the N + 1 initial metal sheets are sequentially overlaid and pressed in an alternate and spaced mode, and a combination of the ceramic substrates and the metal sheets is obtained; sintering the combined body to form a first MCMI substrate; the first MCMI substrate is flattened, and a pretreated MCMI substrate is obtained; carrying out surface metallization treatment on the pretreated MCMI substrate to obtain a final MCMI substrate; wherein N is an integer greater than 0. When the MCMI substrate, namely the multilayer ceramic metal integrated substrate, is applied to a packaging structure, the number of interface layers between dissimilar materials in the packaging structure can be reduced, and the heat dissipation effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of substrates for power electronics and microelectronic packaging, and in particular to an integration method of metal and ceramic substrates, a substrate structure and a composite substrate. Background Art

[0002] The DBC, DBA, and AMB used in the packaging of power electronic devices represented by IGBT are mainly planar structures. The heat generated by the chip is transferred to the heat sink through DBC, DBA, or AMB and dissipated into the surrounding environment. The DPC substrate used in high-power LED packaging, especially FC packaging, is also mainly a planar structure. The heat transmission path generated by the chip is basically the same as that of the power electronic device. It passes through the DPC substrate, is then transferred to the heat sink, and finally dissipated into the surrounding environment. Traditional metallized ceramic substrates mainly include DBC, DBA, AMB, DPC substrates, etc. In the traditional packaging structure, the heat generated by the chip needs to pass through the brazing layer, the metallized ceramic substrate, the brazing layer, and finally be conducted to the heat sink. More interface layers in the heat dissipation path will bring greater thermal resistance, which is not conducive to the rapid dissipation of the heat generated by the chip. The accumulated heat will cause the junction temperature to rise.

[0003] For power electronic devices represented by IGBT, Figure 1 As shown in the figure, the heat generated by the chip passes through a brazing layer, then through DBC or DBA or AMB, and then through another brazing layer, and finally transferred to the heat sink, and dissipated to the surrounding environment in an active or passive way. The entire heat transfer path needs to pass through about 6 layers of interface layers before it can reach the heat sink smoothly. In addition, if the ceramic is directly sintered or welded on the heat sink in order to reduce thermal resistance, this structure will cause serious deformation of the heat sink and ceramic, so that the reliability is extremely poor and cannot be used in actual environments.

[0004] For high-power LEDs, Figure 2 As shown in the figure, the heat generated by the chip first passes through a brazing layer, then through a DPC substrate, then through a brazing layer, and then reaches the copper layer heat sink, and finally through another brazing layer before it can be transferred to the heat sink. After active or passive heat dissipation, the heat is dissipated to the surrounding environment. The entire heat transfer path needs to pass through 6 layers of thermal resistance before it can finally reach the heat sink (aluminum substrate or copper substrate). In addition, in high-power LED packaging, flip chip packaging (FC packaging) or traditional packaging is more commonly used. The spacing between the two electrodes of the chip is generally less than 200 microns. If conventional DBC, DBA, AMB processes are used, it is difficult to meet the minimum line spacing requirement of 200 microns. Therefore, DPC can only be used to thicken the copper layer to about 100 microns to ensure a line spacing of 200 microns. However, the thermal conductivity of a copper layer with a thickness of 100 microns is poor.

[0005] Traditional heat sinks mainly include copper heat sinks, aluminum heat sinks, and aluminum / silicon carbide substrates. The thermal expansion coefficient of metal heat sinks is relatively large, which will have an adverse effect on the metallized ceramic substrate mounted on it, and easily cause failure. Although the thermal expansion coefficient of aluminum / silicon carbide substrates is adjustable, there is a problem of changes in thermal conductivity with the adjustment of the composition. In addition, aluminum / silicon carbide substrates also have problems such as high cost.

[0006] Therefore, a substrate structure that can enhance the heat dissipation effect during packaging is required. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides an integration method of metal and ceramic substrates, a substrate structure and a composite substrate. When the MCMI substrate, i.e., a multilayer ceramic-metal integrated substrate, obtained by the integration method of metal and ceramic substrates is used in a packaging structure, the number of interface layers in the packaging structure can be reduced and the heat dissipation effect can be improved.

[0008] The first method for integrating a metal and a ceramic substrate provided by the present invention comprises the following specific steps:

[0009] Surface treating the ceramic substrate raw materials and cutting them into initial ceramic substrates according to preset specifications;

[0010] Surface treating the metal sheet raw material and cutting it into initial metal sheets according to the preset specifications;

[0011] Superimposing and pressing N of the initial ceramic substrates and N+1 of the initial metal sheets in sequence in an alternating manner to obtain a combination of the ceramic substrate and the metal sheet;

[0012] sintering the assembly to form a first MCMI substrate;

[0013] planarizing the first MCMI substrate to obtain a pre-treated MCMI substrate;

[0014] Surface metallization treatment of the pretreated MCMI substrate to obtain a final MCMI substrate;

[0015] Wherein, N is an integer greater than 0.

[0016] In a possible implementation, in the first metal and ceramic substrate integration method, when surface treating the ceramic substrate raw material, the ceramic substrate surface treatment method is selected according to the metallization process to be used when surface metallizing the pretreated MCMI substrate and the specific material of the ceramic substrate raw material.

[0017] In a possible implementation, in the first method for integrating metal and ceramic substrates, if the DBC process is used for surface metallization of the pre-treated MCMI substrate, the assembly needs to be placed in a nitrogen-protected furnace for sintering when sintering the assembly;

[0018] If the AMB or DBA process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a vacuum furnace and sintered under vacuum conditions when sintering the assembly.

[0019] The present invention also provides a first substrate structure, which is manufactured by the above-mentioned integration method of the first metal and ceramic substrate.

[0020] The present invention also provides a first composite substrate, which is obtained by sintering a metallized ceramic substrate to the first substrate structure as described above.

[0021] The second method for integrating a metal and a ceramic substrate provided by the present invention comprises the following specific steps:

[0022] Surface treating the ceramic substrate raw materials and cutting them into initial ceramic substrates according to preset specifications;

[0023] Surface treating the metal sheet raw material and cutting it into initial metal sheets according to the preset specifications;

[0024] Superimposing and pressing N of the initial ceramic substrates and N+1 of the initial metal sheets in sequence in an alternating manner to obtain a combination of the ceramic substrate and the metal sheet;

[0025] sintering the assembly to form a first MCMI substrate;

[0026] planarizing the first MCMI substrate to obtain a second MCMI substrate;

[0027] sintering at least two of the second MCMI substrates together to obtain a pre-processed MCMI substrate;

[0028] Surface metallization treatment of the pretreated MCMI substrate to obtain a final MCMI substrate;

[0029] Wherein, N is an integer greater than 0.

[0030] In a possible implementation, in the second integrated method of metal and ceramic substrates, when surface treating the ceramic substrate raw material, the ceramic substrate surface treatment method is selected according to the metallization process to be used when surface metallizing the pretreated MCMI substrate and the specific material of the ceramic substrate raw material.

[0031] In a possible implementation, in the second method for integrating metal and ceramic substrates, if the DBC process is used for surface metallization of the pretreated MCMI substrate, the assembly needs to be placed in a nitrogen-protected furnace for sintering when sintering the assembly;

[0032] If the AMB or DBA process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a vacuum furnace and sintered under vacuum conditions when sintering the assembly.

[0033] The present invention also provides a second substrate structure, which is manufactured by the above-mentioned second metal and ceramic substrate integration method.

[0034] The present invention also provides a second composite substrate, which is obtained by sintering a metallized ceramic substrate to the second substrate structure as described above.

[0035] The technical solution provided by the present invention has at least the following beneficial effects:

[0036] 1. The MCMI substrate of the present invention can meet the requirements of narrow line spacing of high-power LEDs, especially the requirements of Flip-ChiP packaging with narrow line spacing and high heat dissipation;

[0037] 2. The MCMI substrate of the present invention can reduce the packaging thermal resistance interface of power electronic devices from 6 layers to 4 layers, significantly improving the heat dissipation performance;

[0038] 3. The MCMI substrate of the present invention can be used to arbitrarily combine various types and orientations to achieve various signal interconnections, which is very suitable for high-density 3D interconnect packaging and can partially replace high-density interconnect substrates (HDI), low-temperature co-fired ceramic substrates (LTCC), and high-temperature co-fired ceramic substrates (HTCC);

[0039] 4. The MCMI substrate of the present invention can realize any design of thermal expansion coefficient between metal and ceramic;

[0040] 5. By using the MCMI substrate of the present invention, the DBC substrate can be directly sintered on the MCMI, which reduces the thermal resistance interface without any deformation, and significantly improves the reliability of the power electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of a typical packaging structure of power electronic devices;

[0042] Figure 2 A schematic diagram of a typical LED packaging structure;

[0043] Figure 3A flow chart of a first method for integrating a metal and a ceramic substrate provided by an embodiment of the present invention;

[0044] Figure 4 A flow chart of a second method for integrating a metal and a ceramic substrate provided by an embodiment of the present invention;

[0045] FIG5( a ) is a schematic diagram of a process flow of vertically sintering an MCMI substrate provided by an embodiment of the present invention;

[0046] FIG5( b ) is a schematic diagram of a process flow of horizontally sintering an MCMI substrate provided by an embodiment of the present invention;

[0047] Figure 6 A schematic diagram of sintering integration of MCMI substrates with different orientations provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0049] The present invention relates to an MCMI substrate for power electronic devices or high-power LED packaging and a corresponding production process. The multilayer ceramic metal integrated substrate is referred to as the MCMI substrate, which belongs to the field of ceramic surface metallization and functionalization. It should be pointed out that the direct copper-clad ceramic substrate in the present invention is referred to as DBC, the direct aluminum-clad ceramic substrate is referred to as DBA, the active metal brazing is referred to as AMB, and the direct electroplated copper is referred to as DPC. In the DBC technical scheme: the copper sheet is oxidized and placed on the ceramic, and the copper sheet and the ceramic are sintered together at high temperature to obtain the DBC substrate. In the DBA technical scheme: according to the different ceramic materials, a transition metal is introduced or not, and aluminum and ceramic are sintered together under high temperature and protective gas or high vacuum conditions to obtain a DBA substrate. In the AMB technical scheme: the active metal solder is printed on both sides of the ceramic, and then the copper and ceramic are superimposed into a sandwich structure, and the copper and ceramic are sintered together at high temperature to obtain an AMB substrate. In the DPC technical scheme: active metal titanium (Ti) and copper (Cu) are sputtered onto the ceramic surface by magnetron sputtering to form a seed layer, and then the DPC substrate is formed by electroplating thickening. When these substrates obtained by traditional production processes are used in power electronic devices or high-power LED packaging, they have many layers of complex interfaces, especially the introduction of dissimilar metals in the brazing process, which causes excessive thermal resistance and is not conducive to the chip quickly dissipating heat to the surrounding environment. In this regard, the present invention solves the defects of the prior art by constructing a vertical multi-layer ceramic-metal integrated substrate.

[0050] Please refer to Figure 35(a) and 5(b), the first method for integrating a metal and a ceramic substrate provided by the present invention comprises the following specific steps:

[0051] S10: Surface-treating the ceramic substrate raw material and cutting it into initial ceramic substrates according to preset specifications.

[0052] In this embodiment, the ceramic substrate raw material refers to ceramic substrates of various specifications and thicknesses, including but not limited to alumina ceramic substrates (Al2O3), aluminum nitride ceramic substrates (AlN), silicon nitride ceramic substrates (Si3N4), zirconium oxide doped toughened alumina substrates (ZTA), etc. The preset specifications are the specifications required for actual production, and in addition to the required substrate size and graphic size, they also include shape, shape and perforation. The shape includes but is not limited to a conventional rectangle, and the perforation includes but is not limited to a round hole or a square hole.

[0053] In a possible implementation, in the first metal and ceramic substrate integration method, when surface treating the ceramic substrate raw material in step S10, the ceramic substrate surface treatment method is selected according to the metallization process to be used when surface metallizing the pretreated MCMI substrate and the specific material of the ceramic substrate raw material.

[0054] In this embodiment, the surface treatment of the ceramic substrate raw material is divided into the following situations: (1) If the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the DBC process, and the specific material of the ceramic substrate raw material is Al2O3 ceramic or ZTA ceramic, then it is only necessary to clean the surface of the Al2O3 ceramic or ZTA ceramic; (2) If the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the DBC process, and the specific material of the ceramic substrate raw material is AlN ceramic, then it is necessary to modify the surface of the AlN ceramic to generate a layer, and then the surface is cleaned; (3) if the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the AMB process, and the specific material of the ceramic substrate raw material is AlN ceramic or Si3N4 ceramic, then after the AlN ceramic or Si3N4 ceramic surface is cleaned, it is necessary to print active metal solder or welding sheet on the surface of the AlN ceramic or Si3N4 ceramic; (4) if the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the DBA process, then it is necessary to form a thinner metal transition layer on the surface of the ceramic substrate raw material.

[0055] S20: Surface-treating the metal sheet raw material and cutting it into initial metal sheets according to the preset specifications.

[0056] In this embodiment, the metal sheet material includes but is not limited to copper (Cu), aluminum (Al), nickel (Ni) and alloys of these metals. Figure 5(a) and5(b) The specifications used when cutting the metal sheet raw material are consistent with the specifications used when cutting the ceramic substrate, so that the two can be superimposed accordingly in the subsequent steps.

[0057] In step S20, the surface treatment of the metal sheet raw material is divided into the following cases: (1) If the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the DBC process, and the specific material of the ceramic substrate raw material is Al2O3 ceramic, AlN ceramic, or ZTA ceramic, then it is necessary to clean the surface of the metal sheet raw material (such as copper) and then pre-oxidize it to form an oxide film on the surface of the metal sheet raw material; (2) If the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the AMB process, and the specific material of the ceramic substrate raw material is AlN ceramic, Si3N4 ceramic, or ZTA ceramic, then it is selected whether to print active metal solder or welding sheet on the surface of the metal sheet raw material (such as copper) according to the surface condition of the ceramic; (3) If the metallization process to be used in the surface metallization treatment of the pre-treated MCMI substrate is the DBA process, and the specific material of the ceramic substrate raw material is AlN ceramic, Si3N4 ceramic, or ZTA ceramic, then it is selected whether to form a certain thickness of transition metal elements on the surface of the metal sheet raw material (such as aluminum) according to the surface condition of the ceramic. Here, pre-oxidation refers to wet oxidation (chemical oxidation) or dry oxidation.

[0058] S30: stacking and pressing N initial ceramic substrates and N+1 initial metal sheets in sequence in an alternating manner to obtain a combination of ceramic substrates and metal sheets; wherein N is an integer greater than 0.

[0059] In this embodiment, the thickness and type of the initial ceramic substrate are not limited to the same thickness and the same type of ceramic, and different thicknesses and different types of ceramics can be used as required to achieve sintering of a multilayer ceramic / metal integrated substrate (MCMI). The thickness and type of the initial metal sheet are not limited to the same thickness and the same type of metal, and different thicknesses and different types of metals can be used as required to achieve sintering of a multilayer ceramic / metal integrated substrate (MCMI).

[0060] S40: sintering the assembly to form a first MCMI substrate.

[0061] In this embodiment, the combination of the ceramic substrate and the metal sheet is placed in a furnace for sintering, so that the metal and the ceramic are tightly combined together to form a multilayer ceramic / metal integrated substrate (MCMI), namely, the first MCMI substrate.

[0062] In a possible implementation, in the first method for integrating metal and ceramic substrates, if the DBC process is used when the surface metallization treatment of the pre-treated MCMI substrate is performed in step S60, the assembly needs to be placed in a nitrogen-protected furnace for sintering in step S40;

[0063] If the AMB or DBA process is used for the surface metallization treatment of the pre-treated MCMI substrate in step S60, the assembly needs to be placed in a vacuum furnace and sintered under vacuum conditions when sintering the assembly in step S40.

[0064] In this embodiment, the combination is placed in the furnace for sintering in the following situations: (1) If in the sintering integration process, the DBC process is used when the pre-treated MCMI substrate is subjected to surface metallization treatment in step S60, it is only necessary to place the combination of the ceramic substrate and the metal sheet in a continuous sintering furnace (tunnel furnace) protected by nitrogen for sintering; (2) If in the sintering integration process, the DBA or AMB process is used when the pre-treated MCMI substrate is subjected to surface metallization treatment in step S60, it is necessary to place the combination of the ceramic substrate and the metal sheet in a vacuum furnace and sinter under vacuum conditions.

[0065] S50a: planarizing the first MCMI substrate to obtain a pre-treated MCMI substrate.

[0066] In this embodiment, when the first MCMI substrate is planarized, the ceramic and metal end faces need to be kept in the same plane, so as to obtain a pre-processed MCMI substrate. Planarization refers to keeping the cross-sections of the ceramic and metal in the same plane by physical or chemical processing means, such as grinding, polishing, mechanochemical polishing (MCP) and other processing means.

[0067] S60: Surface metallization treatment is performed on the pre-treated MCMI substrate to obtain a final MCMI substrate.

[0068] In this embodiment, the surface of the MCMI substrate after planarization, i.e., the pre-treated MCMI substrate, is metallized by a metallization process to obtain the final MCMI substrate. The metallization process refers to any combination of one or more of the DBC process, the AMB process, the DBA process, and the DPC process. The surface metallization treatment includes single-sided or double-sided or multi-sided or all-sided surface metallization, as shown in Figures 5(a) and 5(b), and the surface metallization treatment includes single-sided metallization of the MCMI substrate, double-sided metallization of the MCMI substrate, three-sided metallization of the MCMI substrate, four-sided metallization of the MCMI substrate, and full metallization of the MCMI substrate, etc., and any one of them can be selected according to actual needs, or it can be carried out step by step from single-sided to full.

[0069] The present invention also provides a first substrate structure, which is manufactured by the above-mentioned integration method of the first metal and ceramic substrate.

[0070] In this embodiment, the first substrate structure, namely the MCMI substrate, is manufactured by adopting the first metal and ceramic substrate integration method.

[0071] The present invention also provides a first composite substrate, which is obtained by sintering a metallized ceramic substrate to the first substrate structure as described above.

[0072] In this embodiment, when the metallized ceramic substrate is sintered onto the MCMI substrate, i.e., the first substrate structure, a suitable metallization process needs to be selected. The metallized ceramic substrate refers to one or more metallized substrates such as DBC substrates, AMB substrates, DBA substrates, DPC substrates, thin-film metallization substrates, and thick-film printed substrates. A suitable metallization process refers to one or more of the DBC process, DBA process, AMB process, DPC process, thin-film metallization process, and thick-film printed process according to actual conditions.

[0073] Please refer to Figure 4 5(a) and 5(b), a second method for integrating a metal and a ceramic substrate provided by the present invention comprises the following specific steps:

[0074] S10: Surface-treating the ceramic substrate raw material and cutting it into initial ceramic substrates according to preset specifications.

[0075] S20: Surface-treating the metal sheet raw material and cutting it into initial metal sheets according to the preset specifications.

[0076] S30: stacking and pressing N initial ceramic substrates and N+1 initial metal sheets in sequence in an alternating manner to obtain a combination of ceramic substrates and metal sheets; wherein N is an integer greater than 0.

[0077] S40: sintering the assembly to form a first MCMI substrate.

[0078] S50b: planarizing the first MCMI substrate to obtain a second MCMI substrate.

[0079] In this embodiment, when the first MCMI substrate is planarized, the ceramic and metal end faces need to be kept in the same plane, so as to obtain the second MCMI substrate. Planarization refers to keeping the cross-sections of the ceramic and metal in the same plane by physical or chemical processing means, such as grinding, polishing, mechanochemical polishing (MCP) and other processing means.

[0080] S50c: sintering at least two of the second MCMI substrates together to obtain a pre-processed MCMI substrate.

[0081] In this embodiment, sintering at least two second MCMI substrates together means sintering two or more MCMI substrates having the same orientation or different orientations together. Figure 6 The figure shows a schematic diagram of sintering MCMI substrates with different orientations together, where 1 is the x-axis orientation, 2 is the y-axis orientation, and 3 is the z-axis orientation.

[0082] S60: Surface metallization treatment is performed on the pre-treated MCMI substrate to obtain a final MCMI substrate.

[0083] In a possible implementation, in the second integrated method of metal and ceramic substrates, when surface treating the ceramic substrate raw material, the ceramic substrate surface treatment method is selected according to the metallization process to be used when surface metallizing the pretreated MCMI substrate and the specific material of the ceramic substrate raw material.

[0084] In a possible implementation, in the second method for integrating metal and ceramic substrates, if the DBC process is used for surface metallization of the pretreated MCMI substrate, the assembly needs to be placed in a nitrogen-protected furnace for sintering when sintering the assembly;

[0085] If the AMB or DBA process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a vacuum furnace and sintered under vacuum conditions when sintering the assembly.

[0086] The present invention also provides a second substrate structure, which is manufactured by the above-mentioned second metal and ceramic substrate integration method.

[0087] In this embodiment, the second substrate structure, namely the MCMI substrate, is manufactured by adopting an integration method of the second metal and ceramic substrate.

[0088] The present invention also provides a second composite substrate, which is obtained by sintering a metallized ceramic substrate to the second substrate structure as described above.

[0089] In this embodiment, the first composite substrate and the second composite substrate are described together. The first composite substrate is obtained by packaging based on the first substrate structure, and the specific structure will vary depending on the packaging process and the first substrate structure. The second composite substrate is obtained by packaging based on the second substrate structure, and the specific structure will vary depending on the packaging process and the second substrate structure.

[0090] Assuming that the second composite substrate is synthesized based on an Al2O3-MCMI substrate (i.e., an Al2O3 type MCMI substrate), a specific implementation method is as follows:

[0091] S1: Using a laser cutting machine, the cleaned 138*190*0.38 Al2O3 ceramic substrate is cut into 138*3.00*0.38 (mm) Al2O3 ceramic strips;

[0092] S2: Using a cutting machine, the cleaned 134*184*0.5 (mm) copper sheet is cut into 134*3.00*0.50 (mm) copper strips, and then oxidized under the condition of 200-300 PPM oxygen content to form a composite oxide film on the surface of the copper strips;

[0093] S3: stacking 10 processed Al2O3 ceramic strips and 11 copper strips with oxide films in sequence with intervals between them, placing them in a mold and pressing them tightly so that there is no obvious gap between the Al2O3 ceramic strips and the copper strips;

[0094] S4: Using the DBC process, the combination of the Al2O3 ceramic strip and the copper strip is placed in a nitrogen-protected tunnel furnace for sintering so that the Al2O3 ceramic strip and the copper strip are tightly combined to form a MCMI substrate (the sintering conditions are: the maximum temperature is 1075°C; the holding time is 15 minutes; the oxygen content in the sintering environment furnace is about 100PPM);

[0095] S5: sintering five MCMI substrates together in the same orientation using the DBC process;

[0096] S6: using chemical mechanical polishing (CMP) to keep the ceramic and copper end surfaces of the MCMI substrate after step S5 in the same plane;

[0097] S7: Sintering a copper sheet with a specification of 134*47*0.30 on the MCMI substrate to metallize the upper and lower surfaces of the MCMI substrate;

[0098] S8: Then, the Al2O3-DBC is sintered on the MCMI substrate by using the DBC process, so as to complete the integration of the Al2O3-DBC and the MCMI substrate and obtain the corresponding composite substrate.

[0099] Assuming that the first composite substrate is synthesized based on a Si3N4-MCMI substrate (i.e., a Si3N4 type MCMI substrate), a specific implementation method is as follows:

[0100] S1: Printing active metal solder on a Si3N4 ceramic substrate with a specification of 138*190*0.25 (mm) using a screen printer;

[0101] S2: drying and debinding the Si3N4 ceramic substrate printed with the active metal solder, and then pre-sintering at 800°C to make the active metal solder firmly adhere to the Si3N4 ceramic substrate;

[0102] S3: using a laser cutting machine to cut the Si3N4 ceramic substrate with active metal solder attached into Si3N4 ceramic strips with a size of 138*3.00*0.25 (mm);

[0103] S4: Using a laser cutting machine, the cleaned copper sheet of 134*184*1.2 (mm) is cut into copper strips of 134*3.00*1.2 (mm);

[0104] S5: stacking the prepared 29 Si3N4 ceramic strips and the cut 30 copper strips in sequence with intervals between them, placing them in a mold and pressing them tightly so that there is no obvious gap between the Si3N4 ceramic strips and the copper strips;

[0105] S6: Using the AMB process, the combination of Si3N4 ceramic strips and copper strips is placed in a mold and pressed tightly, and then sintered in a vacuum furnace to make the Si3N4 ceramic strips and copper strips tightly combined to form a Si3N4-MCMI substrate (sintering conditions are: maximum temperature 920°C; holding time 30min; sintering environment furnace vacuum degree 6*10 -2 Pa (about);

[0106] S7: using chemical mechanical polishing (CMP) to keep the ceramic and copper end surfaces of the MCMI substrate after step S7 in the same plane;

[0107] S8: Sinter a copper sheet with a specification of 134*44*0.30 on the MCMI substrate through a soft soldering process to metalize the upper and lower surfaces of the MCMI substrate;

[0108] S9: The AlN-DBC is then soldered to the MCMI substrate using a soft soldering process, thereby completing the integration of the AlN-DBC and the MCMI substrate to obtain a corresponding composite substrate.

[0109] Assuming that the second composite substrate is synthesized based on a ZTA-MCMI substrate (i.e., a ZTA-type MCMI substrate), a specific implementation is as follows:

[0110] S1: Using a laser cutting machine, the cleaned 138*190*0.38 ZTA ceramic substrate is cut into 138*4.5*0.38 (mm) ZTA ceramic strips;

[0111] S2: Using a laser cutting machine, the cleaned copper sheet of 134*184*2.0 (mm) is cut into copper strips of 134*4.5*2.0 (mm), and then oxidized under the condition of 200-300 PPM oxygen content to form an oxide film on the surface of the copper strip;

[0112] S3: stacking 10 processed ZTA ceramic strips and 11 copper strips with oxide films in sequence with intervals between each other, placing them in a mold and pressing them tightly so that there is no obvious gap between the ZTA ceramic strips and the copper strips;

[0113] S4: Using the DBC process, the combination of the ZTA ceramic strip and the copper strip is placed in a nitrogen-protected tunnel furnace for sintering so that the ZTA ceramic strip and the copper strip are tightly combined to form an MCMI substrate (the sintering conditions are: the maximum temperature is 1080°C; the holding time is 30 minutes; the oxygen content in the sintering environment furnace is about 100PPM);

[0114] S5: sintering two MCMI substrates together in the same orientation using the DBC process;

[0115] S6: using chemical mechanical polishing (CMP) to keep the ceramic and copper end surfaces of the MCMI substrate after step S5 in the same plane;

[0116] S7: Sintering a copper sheet with a specification of 134*50.5*0.30 on the MCMI substrate to metalize the upper and lower surfaces of the MCMI substrate;

[0117] S8: Then, the AlN-DBC is sintered on the MCMI substrate by using the DBC process, so as to complete the integration of the AlN-DBC and the MCMI substrate, thereby obtaining the corresponding composite substrate.

[0118] The above embodiments should not limit the present invention in any way, and any technical solutions obtained by equivalent replacement or equivalent conversion shall fall within the protection scope of the present invention.

Claims

1. A method for integrating metal and ceramic substrates, characterized in that: The specific steps include: Surface treating the ceramic substrate raw materials and cutting them into initial ceramic substrates according to preset specifications; Surface treating the metal sheet raw material and cutting it into initial metal sheets according to the preset specifications; Superimposing and pressing N of the initial ceramic substrates and N+1 of the initial metal sheets in sequence in an alternating manner to obtain a combination of the ceramic substrate and the metal sheet; sintering the assembly to form a first MCMI substrate; planarizing the first MCMI substrate to obtain a pre-treated MCMI substrate; Surface metallization treatment of the pretreated MCMI substrate to obtain a final MCMI substrate; Wherein, N is an integer greater than 0.

2. The integrated method according to claim 1, characterized in that: When the ceramic substrate raw material is surface treated, the ceramic substrate surface treatment method is selected according to the metallization process to be used when the MCMI substrate is pretreated and the specific material of the ceramic substrate raw material.

3. The integrated method according to claim 1, characterized in that: If the DBC process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a nitrogen-protected furnace for sintering; If the AMB or DBA process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a vacuum furnace and sintered under vacuum conditions when sintering the assembly.

4. A substrate structure, characterized in that: The invention is manufactured by the integrated method as claimed in any one of claims 1 to 3.

5. A composite substrate, characterized in that: The method is obtained by sintering a metallized ceramic substrate to the substrate structure as claimed in claim 4.

6. A method for integrating a metal and a ceramic substrate, characterized in that: The specific steps include: Surface treating the ceramic substrate raw materials and cutting them into initial ceramic substrates according to preset specifications; Surface treating the metal sheet raw material and cutting it into initial metal sheets according to the preset specifications; Superimposing and pressing N of the initial ceramic substrates and N+1 of the initial metal sheets in sequence in an alternating manner to obtain a combination of the ceramic substrate and the metal sheet; sintering the assembly to form a first MCMI substrate; planarizing the first MCMI substrate to obtain a second MCMI substrate; sintering at least two of the second MCMI substrates together to obtain a pre-processed MCMI substrate; Surface metallization treatment of the pretreated MCMI substrate to obtain a final MCMI substrate; Wherein, N is an integer greater than 0.

7. The integrated method according to claim 6, characterized in that: When the ceramic substrate raw material is surface treated, the ceramic substrate surface treatment method is selected according to the metallization process to be used when the MCMI substrate is pretreated and the specific material of the ceramic substrate raw material.

8. The integrated method according to claim 6, characterized in that: If the DBC process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a nitrogen-protected furnace for sintering; If the AMB or DBA process is used for the surface metallization treatment of the pre-treated MCMI substrate, the assembly needs to be placed in a vacuum furnace and sintered under vacuum conditions when sintering the assembly.

9. A substrate structure, characterized in that: The method is manufactured by the integrated method as described in any one of claims 6 to 8.

10. A composite substrate, characterized in that: The method is obtained by sintering a metallized ceramic substrate to the substrate structure as claimed in claim 9.

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