Method for batch production of multilayered stacks of metal / diamond composite substrates and preform unit

Abstract

The present application relates to the field of powder metallurgy and electronic packaging heat dissipation materials, and discloses a multilayer stacking batch preparation method of a metal / diamond composite material substrate and a preform unit, the method comprising: first, preparing a preform unit composed of a metal substrate containing a metal separation zone and a positioning structure, composite powder and a metal buffer foil; then, vertically stacking multiple groups of the preform units and setting a demolding isolation layer between the layers; through hot-pressing sintering, the metal buffer foil is homogenized to evenly distribute the interlayer pressure, and is metallurgically combined with the composite zone to form a metal-coated layer of the substrate; finally, the multilayer preform is separated along the isolation layer, and through cutting of the metal separation zone, independent metal / diamond composite material single-substrate is obtained in batch. The present application solves the industry problems that metal / diamond powder cannot be stacked in multiple layers, the interlayer pressure is uneven, the substrate surface is damaged, and secondary copper coating is required, and improves the substrate mass production capacity, product quality and production efficiency, and reduces the preparation cost.

Description

Technical Field

[0001] This invention relates to the fields of powder metallurgy and electronic packaging heat dissipation materials, and more specifically, to a method for mass production of multilayer laminated metal / diamond composite substrates and a preform unit. Background Technology

[0002] Existing technologies utilize prefabricated grooved metal plates or metal strip meshes to achieve mass production of planar arrays of m×n substrates within a single sintering mold. However, the planar array approach is limited by mold size, resulting in limited yield per batch. Stacking multiple layers of preform units vertically and sintering them in a single pass to obtain m×n×k substrates is a natural approach to further increase yield.

[0003] However, the lamination and sintering of metal / diamond composite materials faces four unique engineering challenges not present in conventional powder metallurgy laminations: ① Inability to layer mixed powders (fundamental obstacle): The diamond particle density in the metal / diamond mixed powder is high (3.52 g / cm³). 3 The large particle size (>100μm) makes it extremely easy to segregate when loosely packed, making it impossible to stack in multiple layers in the form of mixed powders. This is a problem that does not exist in the stacking and sintering of ordinary metal powders, and it is also the fundamental reason why metal / diamond composite materials have never achieved multi-layer stacking in the existing technology. ② Pressure transmission attenuation: Metal / diamond pre-pressed billets are close to rigid bodies during hot pressing. After lamination, the upper layer bears most of the pressure, while the pressure of the bottom layer is significantly attenuated, and the densification degree of each layer is inconsistent. When ordinary metal powder is laminated, the powder is soft and the pressure can be transmitted evenly, so this problem does not exist. ③ Surface damage: Diamond particles (Mohs hardness 10) come into direct contact with the release layer such as graphite paper during hot pressing and embed themselves into the release layer under high pressure, causing damage to the substrate surface; ordinary metal powder has a hardness much lower than diamond and does not have the problem of embedding into the release layer. ④ Secondary processing of copper cladding: In traditional solutions, copper needs to be applied to the upper and lower copper surfaces of the substrate twice (by welding or electroplating), which increases the number of processes and costs.

[0004] Existing general powder metallurgy laminated sintering patents do not offer systematic solutions to the four unique problems of metal / diamond systems mentioned above. This invention addresses these four problems simultaneously by introducing preformed preform units and metal buffer foils. Summary of the Invention

[0005] In view of this, the present invention proposes a method for batch preparation of multilayer laminated metal / diamond composite substrates and a preform unit, aiming to solve the above-mentioned problems.

[0006] In one aspect, the present invention proposes a method for batch fabrication of multilayer laminated metal / diamond composite substrates, comprising: A preform unit is prepared, which consists of a metal substrate with a positioning structure, a metal / diamond composite powder filled in the positioning structure, and a metal buffer foil covering the top surface. Multiple preformed blank units are stacked vertically, and a demolding isolation layer is provided between adjacent preformed blank units; The stacked multi-layer preformed blank units are hot-pressed and sintered to homogenize the interlayer pressure transmission of the metal buffer foil. After sintering, the metal buffer foil is metallurgically bonded to the composite area composed of metal / diamond composite powder in the positioning structure to form a substrate metal-coated layer. Separate each preform along the interface of the release layer to obtain an independent monolithic metal / diamond composite material substrate.

[0007] Furthermore, in the preparation of the preform unit, the metal substrate of the positioning structure is composed of a metal strip grid and a bottom metal layer.

[0008] Furthermore, in the preparation of the preformed blank unit, the metal substrate of the positioning structure is a pre-grooved metal plate, and the pre-grooved metal plate is provided with grooves arranged in an array, and the walls between adjacent grooves constitute the metal separation area.

[0009] Furthermore, the groove depth of the prefabricated grooved metal plate is equal to the thickness of the target composite area, the bottom of the groove of the prefabricated grooved metal plate retains a metal substrate, the width of the partition wall between adjacent grooves is greater than or equal to 1 mm, and the thickness of the metal substrate retained at the bottom is greater than or equal to 0.5 mm.

[0010] Furthermore, in the preparation of the preformed blank unit, the metal / diamond composite powder is pre-cold-pressed into a pre-pressed block and then filled into the groove of the positioning structure; Each layer of the preform blank unit has an alignment through hole on its metal substrate, and a positioning pin passes through the alignment through hole.

[0011] Furthermore, the metal buffer foil is copper foil, copper alloy foil, or aluminum foil, and the thickness of the metal buffer foil is from 0.1 mm to 2.0 mm; The metal buffer foil clamps and constrains the diamond particles in the metal / diamond composite powder during the hot pressing and sintering process.

[0012] Furthermore, the release layer comprises graphite paper, boron nitride powder layer, aluminum oxide foil, or rigid graphite mold plate, so that the release layer does not metallurgically bond with the metal buffer foil at the sintering temperature.

[0013] Furthermore, during the hot pressing and sintering of the stacked multi-layered preform units, the process includes: Use any one of the following sintering methods: SPS, LTHP, HP, or HIP; set the sintering temperature to 500℃ to 1000℃; set the sintering pressure to 20MPa to 500MPa; set the holding time to 5min to 60min; and set the sintering atmosphere to be a vacuum or inert atmosphere.

[0014] Furthermore, after hot pressing and sintering, the temperature is slowly reduced at a rate of less than or equal to 100℃ / min, and in-situ annealing is carried out by holding the temperature in the range of 300℃ to 400℃ for 1 to 4 hours.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By constructing preformed blank units with metal separators and positioning structures, loose composite powders are solidified into stackable rigid wholes, eliminating the industry pain point that metal / diamond powders cannot be stacked in multiple layers; multi-layer stacking and sintering achieves a doubling of single-batch m×n×k capacity, effectively reducing production costs; relying on the top metal buffer foil, interlayer pressure homogenization, substrate surface protection, and integrated copper plating are simultaneously achieved, ensuring uniform substrate density and excellent finished product quality, eliminating the need for a secondary copper plating process; at the same time, standardized blank units can be circulated independently and are compatible with the entire processing technology chain, constructing an efficient and industrializable mass production system.

[0016] On the other hand, this application also provides a preformed blank unit, which is prepared by a multilayer lamination batch preparation method of metal / diamond composite material substrate; The preformed blank unit is obtained as an array sintered blank after hot pressing and sintering and before separation along the demolding isolation layer interface. The array sintered blank includes multiple layers of stacked sintered blank units, and each layer of sintered blank units is separated by a demolding isolation layer. When the size of the preform unit is the same as the target size of the monolithic metal / diamond composite substrate, the sintered preform obtained is the monolithic metal / diamond composite substrate.

[0017] It is understandable that the above-mentioned method for mass production of metal / diamond composite substrates through multilayer lamination and the preform unit have the same beneficial effects, and will not be elaborated further here. Detailed Implementation

[0018] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0019] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0020] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0021] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0022] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0023] This invention provides a method for batch fabrication of multilayer laminated metal / diamond composite substrates, comprising the following fabrication steps: A preform unit is prepared, which consists of a metal substrate with a metal partition and positioning structure, a metal / diamond composite powder filled in the positioning structure, and a metal buffer foil covering the top surface. Multiple preformed blank units are stacked vertically, and a demolding isolation layer is set between adjacent preformed blank units; The stacked multi-layer preformed blank units are hot-pressed and sintered to homogenize the interlayer pressure transmission of the metal buffer foil. After sintering, the metal buffer foil is metallurgically bonded to the composite area composed of metal / diamond composite powder in the positioning structure to form a substrate metal-coated layer. Separate each preform along the interface of the release layer to obtain an independent monolithic metal / diamond composite substrate.

[0024] Specifically, the metal / diamond composite powder is prepared by mixing metal matrix powder and diamond particles, with the volume fraction of diamond particles controlled at 30%~70 vol; the surface of the diamond particles is pre-plated with titanium or chromium to enhance the interfacial bonding force with the metal matrix powder, the metal matrix powder is selected from copper powder, copper alloy powder or aluminum powder, with a particle size range of 5~20 μm, and the diamond particles have a particle size of 100~300 μm.

[0025] Specifically, the layer separation can be completed by manual peeling without grinding or acid washing to remove the adhesive layer; the cutting method is wire cutting or laser cutting, and the cutting trajectory is along the center line of the metal partition wall. After cutting, the edge of the single substrate is completely covered with metal, with no diamond exposed.

[0026] Specifically, the vertical stacking number of layers k ≥ 2, the stacked layers are aligned and positioned as a whole, and the array cells of the grooved metal substrates of each layer correspond one-to-one, ensuring that the cutting paths of all blanks are uniform after sintering, eliminating the need for individual adjustment of the cutting fixture. Specifically, each layer of the preformed blank unit has an alignment through-hole on its metal substrate, through which a positioning pin passes, achieving precise vertical alignment of the multi-layered blanks, ensuring that the array cells of each layer correspond one-to-one, and ensuring that the cutting paths of all blanks are uniform after sintering.

[0027] Understandably, multi-layer synchronous sintering significantly increases the amount of material produced per batch, and under the same sintering equipment and energy consumption conditions, production efficiency is increased several times over, while marginal production costs continue to decrease as the number of layers increases.

[0028] The above embodiments, by constructing preformed blank units with metal separators and positioning structures, solidify loose composite powder into a stackable rigid whole, eliminating the industry pain point that metal / diamond powder cannot be multi-layered; multi-layered stacking and sintering achieves a doubling of single-batch m×n×k capacity, effectively reducing production costs; relying on the top metal buffer foil to simultaneously achieve interlayer pressure homogenization, substrate surface protection, and integrated copper plating, ensuring uniform substrate density and excellent finished product quality, eliminating the need for a secondary copper plating process; at the same time, standardized blank units can be circulated independently and are compatible with the entire processing technology chain, constructing an efficient and industrializable mass production system.

[0029] Specifically, in the preparation of preform blank units, the metal substrate with metal separation area and positioning structure is composed of a metal strip mesh and a bottom metal layer. The metal strip mesh is fixed to the bottom metal layer by spot welding, brazing or thermally conductive adhesive to form an m×n rectangular array or annular cell.

[0030] Specifically, the metal strip mesh and the bottom metal layer are uniformly made of copper, copper alloy, aluminum or aluminum alloy, and the thickness of the metal strip is not less than 1mm; when brazing is used for fixing, copper-based brazing filler metal is used, and the thermal conductive adhesive is a high-temperature resistant metal thermal conductive adhesive with a temperature range of not less than 1000℃, to avoid the mesh falling off or deforming during the high-temperature sintering process.

[0031] Understandably, the metal strip mesh can be disassembled and assembled, and the number and size of the array cells can be flexibly adjusted to adapt to the production needs of different specifications of heat dissipation substrates. The mold is more versatile and reduces the mold opening cost of multi-specification products.

[0032] Specifically, when preparing the preformed blank unit, the metal substrate with metal partition area and positioning structure adopts a pre-made grooved metal plate. The pre-made grooved metal plate is provided with grooves arranged in an array, and the walls between adjacent grooves constitute the metal partition area.

[0033] Specifically, the prefabricated grooved metal plate is formed by milling and etching in one piece. The number of rows and columns of the groove array, m and n, are independently set to 2 to 10. The total number of cells in a single grooved plate is not less than 4, ensuring the basic production capacity for batch production.

[0034] Understandably, the integrated grooved metal plate has stronger overall rigidity, the cells are less prone to deformation during the sintering process, the size consistency of each individual substrate is higher, the subsequent cutting process is simpler, and the dimensional tolerance is easier to control.

[0035] Specifically, the groove depth of the prefabricated grooved metal plate is equal to the thickness of the target composite area, the bottom of the groove of the prefabricated grooved metal plate retains a metal substrate, the width of the partition wall between adjacent grooves is greater than or equal to 1 mm, and the thickness of the metal substrate retained at the bottom is greater than or equal to 0.5 mm.

[0036] Specifically, the groove depth is controlled within the range of 0.5~5mm; the partition wall width is preferably 1~5mm; the bottom metal layer thickness is preferably 0.5~2mm; after sintering, the bottom metal layer is directly used as the underlayer metal layer of the substrate, forming a fully enclosed metal structure on both the top and bottom of the substrate together with the top metal buffer foil.

[0037] Understandably, the bottom metal substrate at the bottom of the groove works in conjunction with the top metal buffer foil, and after sintering, both the top and bottom of the substrate have their own metal cladding layers, so no additional sealing treatment is required. The partition wall has sufficient cutting allowance, so the internal metal / diamond composite area will not be damaged during cutting.

[0038] Specifically, when preparing the preformed blank unit, the metal / diamond composite powder is pre-pressed into a pre-pressed block and then filled into the groove of the positioning structure.

[0039] Specifically, the cold pressing pressure is controlled at 100~300MPa, and the density of the pre-pressed block after cold pressing reaches 75%~85% of the theoretical density; the gap between the outer dimensions of the pre-pressed block and the inner cavity of the groove is controlled at 0.05~0.2mm, and there is no obvious loosening after filling, to prevent the powder from shifting and leaking during the stacking and sintering stages.

[0040] Understandably, replacing loose powder with pre-compressed blocks results in higher filling efficiency, more uniform powder distribution, avoids the problem of diamond particle sedimentation and segregation during sintering, and ensures uniform and stable thermal conductivity within each substrate.

[0041] Specifically, the metal buffer foil is copper foil, copper alloy foil, or aluminum foil, and the thickness of the metal buffer foil is from 0.1 mm to 2.0 mm; During the hot-pressing sintering process, the metal buffer foil clamps and constrains the diamond particles in the metal / diamond composite powder. Through a dual mechanism of physical interlocking and metallurgical diffusion, it significantly improves the peel strength of the metal coating.

[0042] Specifically, the metal buffer foil completely covers the upper surface of all array cells, with the edge extending 2-5mm beyond the outer partition wall of the groove. After sintering, the metal buffer foil forms a physical interlocking structure with the diamond particles on the one hand, and undergoes metallurgical diffusion bonding with the composite powder on the other hand. This dual bonding significantly improves the peel strength of the metal-coated layer. The thickness of the buffer foil can be adjusted according to the subsequent tooth processing allowance requirements, with a minimum reserved processing allowance of not less than 0.3mm.

[0043] Understandably, the metal buffer foil integrates multiple functions such as pressure equalization, surface protection, and integrated metal coating, which not only solves the problems of pressure attenuation in multi-layer lamination and diamond scratches on the substrate surface, but also eliminates the need for subsequent electroplating and brazing copper bonding processes, simplifying the process flow.

[0044] Specifically, the release layer is graphite paper, boron nitride powder, aluminum oxide foil, or rigid graphite mold plate, so that the release layer does not metallurgically bond with the metal buffer foil at the sintering temperature.

[0045] Specifically, when using rigid graphite mold plates, they have the triple functions of demolding isolation, uniform force transmission, and reusability, further reducing material costs.

[0046] Specifically, the graphite paper thickness is 0.1~0.3mm; the boron nitride powder coating thickness is 0.02~0.08mm; the aluminum oxide foil thickness is 0.05~0.2mm; the release layer is completely and flatly laid on the upper surface of the lower metal buffer foil, without wrinkles or damage, ensuring that the interlayer can be completely peeled off after sintering, without adhesion or tearing of the metal foil.

[0047] Understandably, the isolation layer only contacts the smooth outer surface of the metal buffer foil, preventing diamond particles from being directly embedded in the release layer. After sintering, the interlayer separation is simple, requiring no additional polishing or cleaning, thus reducing substrate surface damage.

[0048] Specifically, the hot pressing and sintering of the stacked multi-layer preform units includes: Use any one of the following sintering methods: SPS, LTHP, HP, or HIP; set the sintering temperature to 500℃ to 1000℃; set the sintering pressure to 20MPa to 500MPa; set the holding time to 5min to 60min; and set the sintering atmosphere to be a vacuum or inert atmosphere.

[0049] Specifically, the vacuum degree of the cavity during vacuum sintering is ≤10. -2 Pa; high-purity argon is used as the inert atmosphere, with a gas flow rate of 80~150mL / min; the heating rate is uniformly controlled at 5~15℃ / min to avoid excessive internal stress caused by rapid heating due to large temperature difference between the inside and outside of the multi-layered billet.

[0050] Understandably, the wide process window is compatible with a variety of mainstream hot pressing sintering equipment, has strong process compatibility, and the vacuum / inert atmosphere can effectively prevent high-temperature oxidation of the metal substrate, ensuring the thermal conductivity of the substrate and the strength of the interface bonding.

[0051] Specifically, after hot pressing and sintering, the temperature is slowly reduced at a rate of less than or equal to 100℃ / min, and in-situ annealing is carried out by holding the temperature in the range of 300℃ to 400℃ for 1 to 4 hours.

[0052] Specifically, the annealing holding temperature is preferably 320~380℃, and after the holding is completed, the furnace is naturally cooled to room temperature. In-situ annealing can release the accumulated thermal stress at the interface of multi-layer stacked billets and the interface between metal and diamond, effectively suppressing warping, edge and corner cracking, and delamination defects of large slab billets.

[0053] It is understandable that the interfacial thermal stress is superimposed after the stacking of multiple layers of blanks. Slow cooling combined with medium-temperature annealing can eliminate internal stress, significantly reduce the warping and cracking rate of the substrate after sintering, and improve the finished product qualification rate.

[0054] Example 1 S1 Preform Preparation Unit A 100×100×4mm T2 copper prefabricated grooved metal plate was used, with a 3×3 array of grooves. The groove dimensions were 28×28mm, the depth was 2mm, the partition wall width was 3mm, and the thickness of the bottom metal layer was 0.8mm. The groove partition walls formed metal separation zones. HPHT diamond with a particle size of 210–230μm was mixed with 5–20μm spherical copper powder to prepare a composite powder with a diamond volume fraction of 60 vol%. After pre-cooling and pressing into a high-density pre-pressed block, it was filled into the groove. A 0.5mm thick T2 copper metal buffer foil was covered on the top surface of the substrate to form a rigid preform unit that can be independently handled and precisely stacked. A total of 3 sets were prepared.

[0055] S2 Multi-layer Stacked Loading Stacked from bottom to top: blank unit 1 → 0.2mm flexible graphite paper release layer → blank unit 2 → graphite paper → blank unit 3, with no release layer on the top layer.

[0056] S3 Hot pressing sintering and annealing SPS sintering is used, with a vacuum level of ≤10. -2 The copper foil was held at 800℃ and 50MPa for 15 minutes during sintering to homogenize interlayer pressure, isolate the diamond and graphite paper, and simultaneously form a metallurgically bonded and mechanically interlocked integrated copper coating with the composite zone. After sintering, it was slowly cooled at 50℃ / min and then held at 350℃ for 2 hours for in-situ annealing to eliminate thermal stress.

[0057] S4 layered cutting output The graphite paper is manually layered along the interface, and each layer is cut along the dividing wall line of the metal separator area. A single sintering process produces 27 substrates.

[0058] It is understandable that if the size of the preform unit is directly set to the target size of the single substrate, then the single substrate is obtained after layering along the graphite paper interface in step S4, without the need for cutting, which further reduces processing steps and material waste.

[0059] Table 1 Summary of Parameters for Example 1

[0060] Example 2 The overall process parameters, stacking structure, sintering regime, and annealing process of this embodiment are completely consistent with those of Embodiment 1. The difference lies in that: the groove is no longer filled with ordinary mixed pre-pressing blocks, but adopts a patented single-layer diamond flat-laying process, so that the diamond particles do not overlap in the thickness direction and are laid out in a single layer, with copper powder filling the gaps between the particles. A metal buffer foil clamps the single-layer diamond structure from above, and together with the bottom positioning metal substrate, it restricts the migration and segregation of diamond particles during high-temperature hot pressing. The remaining stacking method, sintering, annealing, and layer cutting processes remain unchanged. Finally, a single sintering yields 27 metal / diamond heat dissipation substrates with a regular arrangement of single-layer diamonds, which also has the advantages of high production capacity and high thermal conductivity of multi-layer stacking.

[0061] Example 3 Using the preparation process and parameters of Example 1, the resulting substrate after sintering has a 0.5mm integrated sintered copper buffer foil coating on top and a ≥0.5mm copper metal underlayer at the bottom, forming a fully metal-clad structure. The batch-produced substrates are directly fed into the tooth-shaving process to mechanically tooth the copper layer, retaining a ≥0.3mm safety root copper layer to meet the machining allowance requirements of toothed heat sinks. Up to 27 integrated heat sinks with finned structures can be produced in a single batch, achieving full-chain industrialized production from batch sintering to batch tooth-shaving.

[0062] Table 2 Comparison with Existing Common Lamination Technologies

[0063] By constructing preformed blank units with metal separators and positioning structures, loose composite powders are solidified into stackable rigid wholes, eliminating the industry pain point that metal / diamond powders cannot be stacked in multiple layers; multi-layer stacking and sintering achieves a doubling of single-batch m×n×k capacity, effectively reducing production costs; relying on the top metal buffer foil, interlayer pressure homogenization, substrate surface protection, and integrated copper plating are simultaneously achieved, ensuring uniform substrate density and excellent finished product quality, eliminating the need for a secondary copper plating process; at the same time, standardized blank units can be circulated independently, constructing an efficient and industrializable mass production system.

[0064] On the other hand, this application also provides a preformed blank unit, which is prepared by a multilayer lamination batch preparation method of metal / diamond composite material substrate; After hot pressing and sintering, the preformed blank unit is separated along the demolding isolation layer interface to obtain an array sintered blank. The array sintered blank includes multiple layers of stacked sintered blank units, and each layer of sintered blank unit is separated by a demolding isolation layer. When the size of the preform unit is the same as the target size of the monolithic metal / diamond composite substrate, the resulting sintered preform is the monolithic metal / diamond composite substrate.

[0065] It is understandable that when the size of the preform unit is the same as the target size of the monolithic metal / diamond composite substrate, the sintered preform obtained after separation along the demolding isolation layer interface is the monolithic metal / diamond composite substrate, which does not require a cutting process and is especially suitable for the mass production of large-size monolithic substrates that do not require segmentation.

[0066] It is understandable that the above-mentioned method for mass production of metal / diamond composite substrates through multilayer lamination and the preform unit have the same beneficial effects, and will not be elaborated further here.

[0067] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0068] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0069] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0070] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for batch preparation of multilayer laminated metal / diamond composite substrates, characterized in that, include: A preform unit is prepared, which consists of a metal substrate with a positioning structure, a metal / diamond composite powder filled in the positioning structure, and a metal buffer foil covering the top surface. Multiple preformed blank units are stacked vertically, and a demolding isolation layer is provided between adjacent preformed blank units; The stacked multi-layer preformed blank units are hot-pressed and sintered to homogenize the interlayer pressure transmission of the metal buffer foil. After sintering, the metal buffer foil is metallurgically bonded to the composite area composed of metal / diamond composite powder in the positioning structure to form a substrate metal-coated layer. Separate each preform along the interface of the release layer to obtain an independent monolithic metal / diamond composite material substrate.

2. The method for mass production of metal / diamond composite substrates by multilayer lamination according to claim 1, characterized in that, In the preparation of the preform unit, the metal substrate of the positioning structure is composed of a metal strip grid and a bottom metal layer.

3. The method for mass production of metal / diamond composite substrates by multilayer lamination according to claim 1, characterized in that, When preparing the preformed blank unit, the metal substrate of the positioning structure is a pre-grooved metal plate, and the pre-grooved metal plate is provided with grooves arranged in an array, and the walls between adjacent grooves constitute the metal separation area.

4. The method for mass production of multilayer laminated metal / diamond composite substrates according to claim 3, characterized in that, The groove depth of the prefabricated grooved metal plate is equal to the thickness of the target composite area. The bottom of the groove of the prefabricated grooved metal plate retains a metal substrate. The width of the partition wall between adjacent grooves is greater than or equal to 1 mm, and the thickness of the metal substrate retained at the bottom is greater than or equal to 0.5 mm.

5. The method for mass production of metal / diamond composite substrates by multilayer lamination according to claim 4, characterized in that, When preparing the preformed blank unit, the metal / diamond composite powder is pre-cold-pressed into a pre-pressed block and then filled into the groove of the positioning structure; Each layer of the preform blank unit has an alignment through hole on its metal substrate, and a positioning pin passes through the alignment through hole.

6. The method for mass production of multilayer laminated metal / diamond composite substrates according to claim 5, characterized in that, The metal buffer foil is copper foil, copper alloy foil, or aluminum foil, and the thickness of the metal buffer foil is from 0.1 mm to 2.0 mm.

7. The method for mass production of metal / diamond composite substrates by multilayer lamination according to claim 6, characterized in that, The release layer comprises graphite paper, boron nitride powder, aluminum oxide foil, or a rigid graphite mold plate, so that the release layer does not metallurgically bond with the metal buffer foil at the sintering temperature.

8. The method for mass production of metal / diamond composite substrates by multilayer lamination according to claim 7, characterized in that, The hot pressing and sintering of the stacked multi-layered preform units includes: Use any one of the following sintering methods: SPS, LTHP, HP, or HIP; set the sintering temperature to 500℃ to 1000℃; set the sintering pressure to 20MPa to 500MPa; set the holding time to 5min to 60min; and set the sintering atmosphere to be a vacuum or inert atmosphere.

9. The method for mass production of multilayer laminated metal / diamond composite substrates according to claim 8, characterized in that, After hot pressing and sintering, the temperature is slowly reduced at a rate of less than or equal to 100℃ / min, and then in-situ annealed for 1 to 4 hours at a temperature range of 300℃ to 400℃.

10. A preformed blank unit, characterized in that, It is prepared by the multilayer lamination batch preparation method of metal / diamond composite material substrate according to any one of claims 1-9; The preformed blank unit is obtained as an array sintered blank after hot pressing and sintering and before separation along the demolding isolation layer interface. The array sintered blank includes multiple layers of stacked sintered blank units, and each layer of sintered blank units is separated by a demolding isolation layer. When the size of the preform unit is the same as the target size of the monolithic metal / diamond composite substrate, the sintered preform obtained is the monolithic metal / diamond composite substrate.

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