Multilayer board with copper substrate inverted-dome copper bar compression and preparation process thereof

Abstract

This invention provides a multilayer board with copper substrate and inverted boss copper busbars, comprising: a first boss plate with a mesh partition formed on the front side by resin, and a second boss plate with a mesh partition formed on the back side by resin; the back side of the second boss plate and the front side of the first boss plate are interlocked to form a multilayer board; wherein, the first boss plate is provided with a copper boss; this invention solves the technical problems of multilayer boards that require both overload current and heat dissipation, while also reducing the technical defects in the manufacturing process such as etching and lamination difficulties, increased copper foil area affecting heat dissipation efficiency, and potential voids inside the vias when using arrayed heat-conducting vias for vertical heat conduction.

Description

Technical Field

[0001] This invention relates to the field of multilayer boards and their preparation technology, and particularly to a multilayer board with copper substrate and copper busbars laminated with inverted bosses and its preparation process. Background Technology

[0002] Multilayer boards are circuit boards composed of three or more conductive layers. Insulating and conductive layers are stacked alternately through a lamination process, and electrical connections between layers are achieved through vias. When using existing multilayer boards, due to design and usage requirements, they need to both handle overcurrent and dissipate heat. Current technologies increase the thickness of the copper foil or the area of ​​the copper foil. However, during the manufacturing process, excessive copper foil thickness can lead to difficulties in etching and lamination, while increasing the area of ​​the copper foil can affect heat dissipation efficiency. In addition, a common heat dissipation method is to use arrayed thermal vias for vertical heat conduction. However, in the actual manufacturing process, arrayed thermal vias may have a process defect where voids may exist inside the vias. Therefore, there is a lack of technical solutions that can address the challenges of overload current and heat dissipation in multilayer boards, while also reducing process defects such as etching and lamination difficulties, increased copper foil area affecting heat dissipation efficiency, and potential voids inside vias during vertical heat conduction in arrayed overheating vias. Summary of the Invention

[0003] The invention provides a multilayer board with copper substrate inverted boss copper busbars and its manufacturing process, which solves the technical problems of multilayer boards that need to both overload current and heat dissipation. At the same time, it can also reduce the technical defects caused by the corresponding processes during production and manufacturing, such as etching and lamination difficulties, increased copper foil area affecting heat dissipation efficiency, and the possibility of voids inside the vias when the array of overheating vias is used for vertical heat conduction.

[0004] This invention provides a multilayer board with copper substrate and inverted boss copper busbars laminated together, comprising: The first boss plate has a grid partition formed on its front side using resin. The second boss plate has a grid partition formed on the back by resin; The back of the second boss plate interlocks with the front of the first boss plate to form a multi-layer board; The first boss plate is provided with a copper boss.

[0005] Preferably, the first boss plate includes: a copper substrate one, the front side of which is pressed together with a copper substrate two through a dielectric layer one, and a copper boss one is provided on the copper substrate two; The second boss plate includes: a copper substrate three, the back of which is pressed together with the copper substrate two through a dielectric layer two, and is disposed on the front of the copper substrate one at intervals from the copper substrate two.

[0006] Preferably, the back side of the copper substrate three is provided with a copper boss two, and the copper boss two is pressed onto the front side of the copper substrate two through a dielectric layer two.

[0007] Preferably, the copper substrate three has slots; and the upper surfaces of the copper substrate two, the dielectric layer two, and the copper substrate three are on the same horizontal plane, and each of them has an electroplated layer.

[0008] In this invention, the multilayer board with copper substrate and inverted boss copper busbars is prepared by a multilayer board manufacturing process, which includes: A depth-controlled etching is performed on the front side of the copper substrate to form a depth-controlled groove on the front side of the copper substrate; the depth-controlled groove is filled with resin so that the filled resin forms multiple grid partitions on the front side of the copper substrate; the resin on the surface of the grid partitions is polished so that the resin surface is flush with the opening end face of the depth-controlled groove, or flush with the front side of the copper substrate. The back side of the copper substrate three is etched with controlled depth to form a controlled depth groove on the back side of the copper substrate three, and the controlled depth groove is filled with resin; the resin on the back side of the copper substrate three is ground so that the resin surface is flush with the opening end face of the controlled depth groove, or flush with the back side of the copper substrate three; a copper boss one is formed on the front side of the copper substrate one, and a copper boss two is formed on the back side of the copper substrate three. An insulating and thermally conductive dielectric layer is laminated onto the front side of copper substrate one and the back side of copper substrate three, respectively, so that the insulating and thermally conductive dielectric layer is flush with the upper surface of copper boss one and the surface of copper boss two, respectively. The back side of copper substrate three is inverted and pressed against the front side of copper substrate one, and copper substrate three, copper substrate one, insulating and thermally conductive dielectric layer, copper boss one and copper boss two are formed into a multilayer board by pressing.

[0009] Preferably, the depth of controlled etching on the front side of the copper substrate is half the thickness of the copper substrate, and the depth of controlled etching on the back side of the copper substrate is half the thickness of the copper substrate. The depth control grooves on the front side of the copper substrate are filled with resin to form intersecting grid partitions, and the depth control grooves on the back side of the copper substrate are filled with resin to form intersecting grid partitions. The copper substrate one and copper substrate three respectively divide the surface of their respective copper substrates into multiple mutually separated regions through the grid partition.

[0010] Preferably, the method for forming the copper boss includes: At least two etching operations are performed on the front side of the copper substrate to form an etching depth control area on the front side of the copper substrate for accommodating the copper boss. The copper boss is pressed into the etching depth control area; The resin protruding from the front of the copper substrate after lamination is ground to make the upper surface of the copper boss flush with the adjacent insulating and thermally conductive dielectric layer.

[0011] Preferably, the method for forming the second copper boss includes: At least two etching operations are performed on the back side of the copper substrate three to form an etching depth control area on the back side of the copper substrate three for accommodating the copper boss two. The copper boss is pressed into the etching depth control area; The resin protruding from the back of the copper substrate after lamination is ground to make the surface of the copper boss flush with the adjacent insulating and thermally conductive dielectric layer.

[0012] Preferably, the etching depth on the back side of the third copper substrate corresponds to the thickness of the first copper substrate, and the thickness of the second copper boss corresponds to the thickness of the first copper substrate. The thickness of the copper boss corresponds to the thickness of the copper substrate. After copper substrate three and copper substrate one are pressed together under an inverted manner, copper boss one and copper boss two respectively form copper conductive paths for transmitting large currents.

[0013] Preferably, the insulating thermally conductive medium layer is a PP insulating thermally conductive adhesive layer with a thickness of 0.1 mm; The thickness of the copper substrate is not less than 0.5 mm; The copper substrate one or copper substrate three is provided with slots, which are located between copper bosses or on the side of the copper bosses away from the insulating and thermally conductive medium layer. The slots are used to form heat dissipation channels, or to fill the slots with heat dissipation material to form a heat dissipation structure; After the interconnected areas of the first copper substrate, the second copper substrate, the dielectric layer, and the third copper substrate are formed into a plane, an electroplating layer is provided on the plane to form a conductive connection area for transmitting small currents.

[0014] Preferred options also include: The local thickness and initial warpage state of the copper substrate are collected in a gridded manner, and an initial manufacturing state matrix containing local thickness and local warpage is established. Based on the local thickness and the local warpage, corresponding target depth control etching parameters are generated for different mesh regions, and staged depth control etching is performed according to the target depth control etching parameters to form depth control mesh grooves. Three-dimensional morphology detection is performed on the etched depth control grid grooves to obtain the actual groove volume of each depth control grid groove, and staged vacuum resin filling is performed according to the actual groove volume and resin rheological state; during the resin curing process, zoned thermal compensation is performed according to the local temperature difference between the copper area and the resin area, and the curing termination time of the corresponding area is determined according to the curing state of each area. The local height difference between the cured copper surface and the resin surface is collected to form a height difference map, and adaptive grinding and leveling are performed based on the height difference map; the size and surface condition of the copper boss to be pressed are detected, error matching and grouping are performed according to the detection results, and pressing is performed according to the local contact state of each copper boss. During the pressing process, the pressing parameters are adjusted according to the pressing displacement change. The relative thermal displacements of copper boss one and copper boss two at the target lamination temperature are obtained respectively. The compensation amount of the undercut position at room temperature is determined based on the relative thermal displacement, and multi-region three-dimensional dynamic alignment is performed based on the compensated undercut position. During the lamination process, the pressure and thickness changes in different areas are acquired in real time, and the lamination pressure is dynamically adjusted based on the deviation of local pressure from the average pressure and the rate of thickness change. When it is detected that a local area has formed a contact pressure higher than other areas in advance, the pressure increase is paused and the current temperature and pressure state is maintained until the pressure difference between the local area and other areas returns to the preset allowable range before the pressure is increased again; after lamination is completed, the cooling rate is controlled according to the thickness change rate during the cooling process, and the pressure is depressurized by segmented pressure reduction; finally, the defect category and defect location corresponding to the quality inspection results are back-linked to the process parameters of the corresponding previous process.

[0015] The working principle and beneficial effects of this invention are as follows: In this invention, copper boss one and copper boss two, which are inverted on the front and back, are connected in the vertical direction, so that a large current flows along the path of copper boss one, copper substrate two, and copper boss two. The equivalent current cross-sectional area is increased by 3-5 times compared with a single layer of copper surface. A single multilayer board can carry a large current of >200A, which is far greater than that of ordinary thick copper plates (≤100A).

[0016] The mesh partition slots between the copper bosses can serve as air cooling channels or be filled with thermally conductive materials to form an efficient heat dissipation path, increasing the heat dissipation area by more than 40% compared to ordinary PCBs and reducing thermal resistance by more than 30%.

[0017] By replacing thick copper etching with controlled depth etching and resin filling processes, the side etching and lamination difficulties of thick copper etching above 3oz are avoided. By replacing electroplating with a boss pressing process, the process defects of electroplated copper are avoided; by replacing via heat conduction with an inverted snap-fit ​​process, the void defects inside the via are avoided.

[0018] By using a design where high current is carried by copper bosses and low current signals are carried by electroplated layers, crosstalk between high and low currents on the same copper surface is avoided, thus improving electrical performance.

[0019] The grid-partitioned resin serves both as electrical insulation and mechanical support for the copper bosses, while also forming a heat dissipation channel. It features a compact structure and high functional integration.

[0020] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the present invention; Among them, 1-copper substrate one, 2-copper substrate two, 3-dielectric layer one, 4-dielectric layer two, 5-copper boss two, 6-copper boss one, 7-electroplated layer, 8-copper substrate three. Detailed Implementation

[0023] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] according to Figure 1 As shown, this embodiment of the invention provides a multilayer board with copper substrate inverted boss copper busbars laminated together, comprising: Copper boss 6, which forms a grid partition on the front side using resin. Copper boss 25, which forms a grid partition on the back side with resin; The back of copper boss 25 and the front of copper boss 16 interlock to form a multi-layer board; Among them, copper boss 6 is provided on copper boss 6.

[0025] In this invention, copper boss 6 and copper boss 5 are respectively formed into a grid partition on the front and back sides by resin, and the grid partition divides the surface of each boss plate into multiple mutually separated areas.

[0026] The back of copper boss 2 5 and the front of copper boss 1 6 are interlocked. Copper boss 1 6 is vertically aligned with the corresponding position of copper boss 2 5, and copper boss 1 6 and copper boss 2 5 are in an up-down docking relationship.

[0027] When the multilayer board carries current, the current is transmitted vertically along the copper boss-6 and the copper path it is connected to. The resin mesh partition provides electrical isolation for adjacent conductive areas, and the cavity formed by the mesh partition serves as a heat dissipation channel to conduct heat away.

[0028] In this invention, a copper conductive path is formed in the vertical direction by the inverted boss structure, which can achieve high current carrying capacity without simply relying on increasing the thickness of the copper foil, thus avoiding the difficulties of thick copper etching and lamination. The grid partition simultaneously provides electrical insulation, mechanical support, and heat dissipation channels, solving the problem of multilayer boards needing both overload current and heat dissipation. Replacing the vertical heat conduction of vias with boss mating method avoids the process defects of voids inside vias, improving the reliability and heat dissipation capacity of multilayer boards.

[0029] In this invention, the copper boss 6 and copper boss 5, which are inverted on the front and back sides, are connected in the vertical direction, so that the large current flows along the path of copper boss 6, copper substrate 2, and copper boss 5. The equivalent current cross-sectional area is increased by 3-5 times compared with a single layer of copper surface, and a single multilayer board can carry a large current of >200A, which is far greater than the ≤100A of ordinary thick copper plate.

[0030] The mesh partition slots between the copper bosses can serve as air cooling channels or be filled with thermally conductive materials to form an efficient heat dissipation path, increasing the heat dissipation area by more than 40% compared to ordinary PCBs and reducing thermal resistance by more than 30%.

[0031] By replacing thick copper etching with controlled depth etching and resin filling processes, the side etching and lamination difficulties of thick copper etching above 3oz are avoided. By replacing electroplating with a boss pressing process, the process defects of electroplated copper are avoided; by replacing via heat conduction with an inverted snap-fit ​​process, the void defects inside the via are avoided.

[0032] By using a design where high current is carried by copper bosses and low current signals are carried by electroplated layer 7, crosstalk between high and low currents on the same copper surface is avoided, thus improving electrical performance.

[0033] The grid-partitioned resin serves both as electrical insulation and mechanical support for the copper bosses, while also forming a heat dissipation channel. It features a compact structure and high functional integration.

[0034] In one embodiment, the copper boss 6 includes: a copper substrate 1, the front side of which is pressed together with a copper substrate 2 via a dielectric layer 3, and the copper substrate 2 is provided with the copper boss 6. The second copper boss 5 includes: a third copper substrate 8, the back side of which is pressed together with the second copper substrate 2 through a second dielectric layer 4, and is disposed on the front side of the first copper substrate 1 at intervals from the second copper substrate 2.

[0035] The back side of the copper substrate 2 has a copper boss 5, which is pressed onto the front side of the copper substrate 2 through the dielectric layer 4.

[0036] In this embodiment, copper substrate 1 serves as the base for copper boss 6, and its front side is bonded to copper substrate 2 through dielectric layer 3. Copper boss 6 is disposed on copper substrate 2.

[0037] Copper substrate 3 8 serves as the base for copper boss 2 5. Its back side is bonded to copper substrate 2 2 via dielectric layer 2 4. Copper substrate 3 8 and copper substrate 2 2 are arranged at intervals on the front side of copper substrate 1. Copper boss 2 5 is disposed on the back side of copper substrate 3 8 and bonded to the front side of copper substrate 2 2 via dielectric layer 2 4.

[0038] After the two boss plates are snapped together, copper boss 1 6 and copper boss 2 5 are vertically aligned to form a continuous copper conductive path. Dielectric layer 1 3 and dielectric layer 2 4 provide insulation between copper substrate 1, copper substrate 2 and copper substrate 3 8 and firmly bond each layer together.

[0039] In this embodiment, the stacking connection relationship between each copper substrate, dielectric layer and copper boss of the multilayer board is clarified, so that the large current flows along the path of copper boss 1 6, copper substrate 2 2 and copper boss 2 5, and the equivalent current cross-sectional area is increased several times compared with the single copper surface, and a single multilayer board can carry a large current. The dielectric layer not only achieves interlayer insulation but also firmly bonds the layers together, resulting in a compact overall structure and high mechanical strength for the multilayer board.

[0040] In one embodiment, the copper substrate 3 8 is provided with slots; and the upper surfaces of the copper substrate 2, the dielectric layer 2, and the copper substrate 3 8 are on the same horizontal plane, and an electroplating layer 7 is provided on the same horizontal plane.

[0041] In this embodiment, slots are formed on the copper substrate 38. The slots are located between the copper bosses or on the side of the copper bosses away from the insulating thermally conductive medium layer. The slots are used to form heat dissipation channels, or to fill the slots with heat dissipation material to form a heat dissipation structure.

[0042] The upper surfaces of copper substrate 2, dielectric layer 4 and copper substrate 8 are processed to be on the same horizontal plane. An electroplating layer 7 is provided on this horizontal plane, covering the interconnected copper substrate areas to form a conductive connection area for transmitting small current signals.

[0043] When the multilayer board is working, the large current is transmitted through the copper path formed by the copper boss and the copper substrate, the small current signal is transmitted through the electroplated layer 7, and the slot area continuously exchanges heat.

[0044] In this embodiment, the large current is transmitted through the copper boss and the copper substrate, while the small current signal is transmitted through the electroplating layer 7. The large and small currents are transmitted in layers without interfering with each other, avoiding crosstalk between the large and small currents on the same copper surface and improving electrical performance. The slots form heat dissipation channels or accommodate heat dissipation materials, further reducing thermal resistance, preventing localized overheating of multilayer boards, and improving heat dissipation uniformity and operational reliability.

[0045] The multilayer board with copper substrate undercut boss copper busbars provided by the present invention is obtained by a multilayer board manufacturing process, the manufacturing process of which includes: The front side of the copper substrate 1 is etched with controlled depth to form a controlled depth groove on the front side of the copper substrate 1; the controlled depth groove is filled with resin so that the filled resin forms multiple grid partitions on the front side of the copper substrate 1; the resin on the surface of the grid partitions is polished so that the resin surface is flush with the opening end face of the controlled depth groove or flush with the front side of the copper substrate 1. The back side of the copper substrate 3 8 is etched with controlled depth to form a controlled depth groove on the back side of the copper substrate 3 8, and the controlled depth groove is filled with resin; the resin on the back side of the copper substrate 3 8 is polished so that the resin surface is flush with the opening end face of the controlled depth groove, or flush with the back side of the copper substrate 3 8; a copper boss 1 6 is formed on the front side of the copper substrate 1, and a copper boss 2 5 is formed on the back side of the copper substrate 3 8. An insulating and thermally conductive dielectric layer is pressed onto the front side of copper substrate 1 and the back side of copper substrate 3 8 respectively, so that the insulating and thermally conductive dielectric layer is flush with the upper surface of copper boss 1 6 and the surface of copper boss 2 5 respectively. The back side of copper substrate 38 and the front side of copper substrate 1 are interlocked and pressed together to form a multilayer board consisting of copper substrate 38, copper substrate 1, insulating and thermally conductive dielectric layer, copper boss 16 and copper boss 25.

[0046] In this embodiment, firstly, the front side of the copper substrate 1 is subjected to controlled-depth etching to form a controlled-depth groove of a predetermined depth. Then, resin is filled into the controlled-depth groove, and the filled resin forms multiple grid partitions on the front side of the copper substrate 1. Subsequently, the resin on the surface of the grid partition is ground so that the resin surface is flush with the end face of the depth control groove or with the front side of the copper substrate.

[0047] The back side of the copper substrate 38 was subjected to controlled-depth etching, resin filling, and polishing in the same manner to form a grid partition.

[0048] Subsequently, a copper boss 6 is formed on the front side of the copper substrate 1, and a copper boss 2 5 is formed on the back side of the copper substrate 8.

[0049] An insulating and thermally conductive dielectric layer is laminated onto the front side of copper substrate 1 and the back side of copper substrate 3, respectively, so that the insulating and thermally conductive dielectric layer is flush with the upper surface of copper boss 16 and the surface of copper boss 25, respectively.

[0050] Finally, the back side of copper substrate 38 and the front side of copper substrate 1 are flipped together and pressed together to form a multilayer board consisting of copper substrate 38, copper substrate 1, insulating and thermally conductive medium layer, copper boss 16 and copper boss 25. Copper boss 16 and copper boss 25 are connected in the vertical direction to form a conductive path.

[0051] In this embodiment, a process of controlled-depth etching combined with resin filling is used instead of thick copper etching, which avoids the problems of severe side etching and lamination difficulties in thick copper etching; a boss lamination process is used instead of electroplating to thicken the copper layer, which avoids the process defects of electroplated copper layer. In this embodiment, the reverse pressing process is used instead of the through-hole vertical heat conduction, avoiding the void defects inside the through-hole; the overall process is stable and controllable, and the multilayer board prepared has both high current carrying capacity and efficient heat dissipation performance.

[0052] In one embodiment, the depth of controlled etching on the front side of the copper substrate 1 is half the thickness of the copper substrate 1, and the depth of controlled etching on the back side of the copper substrate 8 is half the thickness of the copper substrate 8. The depth control groove on the front side of the copper substrate 1 is filled with resin to form intersecting grid partitions, and the depth control groove on the back side of the copper substrate 8 is filled with resin to form intersecting grid partitions. The copper substrate 1 and copper substrate 3 8 respectively divide the surface of the corresponding copper substrate into multiple mutually separated regions through the grid partition.

[0053] In this embodiment, during controlled-depth etching, the etching depth on the front side of copper substrate 1 is controlled to half the thickness of copper substrate 1, and the etching depth on the back side of copper substrate 8 is controlled to half the thickness of copper substrate 8, so as to ensure that the copper substrate retains sufficient structural strength after etching.

[0054] After being filled with resin, the depth control grooves on the front side of copper substrate 1 form intersecting grid partitions. Similarly, the depth control grooves on the back side of copper substrate 3 8 form intersecting grid partitions. The intersecting grids divide the surface of the copper substrate into multiple mutually separated areas, each of which independently carries the corresponding copper boss or conductive function.

[0055] When the multilayer board is in operation, the conductive structures in each partition area do not interfere with each other, and the grooves between the resin partitions form a crisscrossing heat dissipation channel.

[0056] In this embodiment, the semi-thickness etching retains the mechanical strength of the copper substrate while forming a sufficiently deep cavity, avoiding etching penetration and a decrease in the overall strength of the substrate. Intersecting grid partitions insulate each conductive area from each other and prevent interference, while forming crisscrossing heat dissipation channels for more uniform heat dissipation, thus improving the current carrying capacity, structural strength, and heat dissipation performance of the multilayer board.

[0057] In one embodiment, the method for forming the copper boss 6 includes: At least two etching operations are performed on the front side of the copper substrate 1 to form an etching depth control area on the front side of the copper substrate 1 for accommodating the copper boss 6. Press the copper boss 6 into the etching depth control area; The resin protruding from the front of the copper substrate 1 after lamination is ground to make the upper surface of the copper boss 6 flush with the adjacent insulating and thermally conductive dielectric layer.

[0058] In this embodiment, a depth-controlled etching region is formed on the front side of the copper substrate 1 by at least two etching operations. The depth-controlled etching region is used to accommodate the copper boss 6.

[0059] The copper boss 6 is pressed into the etching depth control area. During the pressing process, excess resin around the copper boss 6 is squeezed out and protrudes from the front side of the copper substrate 1. The protruding resin is then ground to remove excess resin, making the upper surface of the copper boss-6 flush with the adjacent insulating and thermally conductive dielectric layer. This flush surface provides a smooth contact surface for subsequent undercutting and pressing.

[0060] In this embodiment, at least two etching operations improve the depth control accuracy of the etching depth control area, ensuring the accuracy of the installation position and depth of the copper boss-6. Grinding after pressing makes the upper surface of the copper boss-6 flush with the insulating and thermally conductive medium layer, avoiding the step effect, ensuring uniform contact during subsequent reverse pressing, and improving the reliability of the conductive connection and the pressing quality.

[0061] In one embodiment, the method for forming the copper boss 5 includes: At least two etching operations are performed on the back side of the copper substrate 3 8 to form an etching depth control area on the back side of the copper substrate 3 8 for accommodating the copper boss 2 5. Press the copper boss 25 into the etching depth control area; The resin protruding from the back of the copper substrate 38 after lamination is ground to make the surface of the copper boss 25 flush with the adjacent insulating and thermally conductive dielectric layer.

[0062] In this embodiment, a depth-controlled etching region is formed on the back side of the copper substrate 3 8 by at least two etching operations. The depth-controlled etching region is used to accommodate the copper boss 2 5.

[0063] Copper boss 25 is pressed into the etch depth control area. During the pressing process, excess resin around copper boss 25 is squeezed out and protrudes from the back of copper substrate 38. The protruding resin is then ground to make the surface of copper boss 25 flush with the adjacent insulating and thermally conductive dielectric layer. The flush surface provides a flat contact surface for subsequent inverted pressing.

[0064] In this embodiment, at least two etching operations ensure the accuracy of the installation position and depth of the copper boss 25; grinding after pressing makes the surface of the copper boss 25 flush with the insulating and heat-conducting medium layer, avoiding the step effect and ensuring reliable docking of the copper boss 25 and the copper boss 16 during subsequent reverse pressing, thereby improving the connection reliability of the high current path.

[0065] In one embodiment, the etching depth on the back side of the copper substrate 3 8 corresponds to the thickness of the copper substrate 1, and the thickness of the copper boss 2 5 corresponds to the thickness of the copper substrate 1. The thickness of the copper boss-6 corresponds to the thickness of the copper substrate-1. After copper substrate 38 and copper substrate 1 are pressed together under an inverted manner, copper boss 16 and copper boss 25 respectively form copper conductive paths for transmitting large currents.

[0066] In this embodiment, the etching depth on the back side of copper substrate 3 8 corresponds to the thickness of copper substrate 1, the thickness of copper boss 2 5 corresponds to the thickness of copper substrate 1, and the thickness of copper boss 6 corresponds to the thickness of copper substrate 1.

[0067] During the inverted pressing, the back side of copper substrate 3 8 is pressed against the front side of copper substrate 1. Since the thickness of copper boss 1 6 and copper boss 2 5 corresponds to the thickness of copper substrate 1, copper boss 1 6 and copper boss 2 5 are precisely aligned in the vertical direction to form a continuous copper conductive path.

[0068] When the multilayer board is working, the large current is transmitted along the copper path formed by copper boss 6, copper substrate 2, and copper boss 5.

[0069] In this embodiment, the thickness correspondence ensures that after the copper boss 1 6 and copper boss 2 5 are precisely aligned in the vertical direction after the inverted pressing, forming a complete high current conductive path. The equivalent current cross-sectional area is increased several times compared with a single layer of copper surface, and a single multilayer board can carry a large current. The thickness-matched design ensures that the interlayer heights match and make full contact after the inverted pressing, avoiding poor contact and gaps, and improving the stability and reliability of high current transmission.

[0070] In one embodiment, the insulating thermally conductive medium layer is a PP insulating thermally conductive adhesive layer with a thickness of 0.1 mm; The thickness of the copper substrate 1 is not less than 0.5 mm; The copper substrate 1 or copper substrate 3 8 is provided with slots, which are located between copper bosses or on the side of the copper bosses away from the insulating thermally conductive medium layer. The slots are used to form heat dissipation channels, or to fill the slots with heat dissipation material to form a heat dissipation structure; After the interconnection areas of the copper substrate 1, the copper substrate 2, the dielectric layer and the copper substrate 3 8 are formed into a plane, an electroplating layer 7 is provided on the plane to form a conductive connection area for transmitting small currents.

[0071] In this embodiment, the insulating and thermally conductive medium layer is a PP insulating and thermally conductive adhesive layer with a thickness of 0.1 mm, which has both insulating and thermally conductive functions. The thickness of the copper substrate 1 is not less than 0.5 mm to ensure that the copper substrate has sufficient load-bearing capacity and structural rigidity.

[0072] Slots are provided on copper substrate 1 or copper substrate 3. The slots are located between copper bosses or on the side of the copper bosses away from the insulating thermally conductive medium layer. The slots form heat dissipation channels, or heat dissipation materials are filled in the slots to form heat dissipation structures.

[0073] After the interconnection areas of copper substrate 1, copper substrate 2, dielectric layer and copper substrate 3 are formed into a plane, an electroplated layer 7 is provided on the plane, and the electroplated layer 7 forms a conductive connection area for transmitting small current signals.

[0074] When the multilayer board is working, the large current is transmitted through the copper boss path, the small current signal is transmitted through the electroplated layer 7, and the slot area is continuously cooled.

[0075] In this embodiment, the PP insulating thermally conductive adhesive layer achieves interlayer insulation while efficiently conducting heat, and its 0.1mm thickness ensures thermal conductivity. The copper substrate thickness of not less than 0.5mm ensures the structural load-bearing capacity; the slotted heat dissipation channels further improve heat dissipation efficiency and avoid local overheating; The electroplated layer 7 is used to transmit small current signals independently, while the copper bosses that carry large currents are arranged in layers to avoid crosstalk between small and large currents and improve electrical performance.

[0076] In one embodiment, the manufacturing process is a full-process adaptive control process based on state transfer parameters, where the actual detection results and actual processing results of the preceding process serve as process input parameters for the subsequent process; specifically including: The local thickness and initial warpage state of the copper substrate are collected in a gridded manner, and an initial manufacturing state matrix containing local thickness and local warpage is established. Based on the local thickness and the local warpage, corresponding target depth control etching parameters are generated for different mesh regions, and staged depth control etching is performed according to the target depth control etching parameters to form depth control mesh grooves. The 3D morphology of the etched depth control grid grooves is inspected to obtain the actual groove volume of each depth control grid groove, and a staged vacuum resin filling is performed according to the actual groove volume and resin rheological state. During the resin curing process, zoned thermal compensation is performed based on the local temperature difference between the copper zone and the resin zone, and the curing termination time of the corresponding zone is determined according to the curing state of each zone. The local height difference between the cured copper surface and the resin surface is collected to form a height difference map, and adaptive grinding and leveling are performed based on the height difference map; The dimensions and surface condition of the copper bosses to be pressed are inspected, and error matching and grouping are performed based on the inspection results. Pressing is then performed according to the local contact state of each copper boss, and the pressing parameters are adjusted according to the pressing displacement changes during the pressing process. The relative thermal displacements of copper boss 1 6 and copper boss 2 5 at the target lamination temperature are obtained respectively. The compensation amount of the undercut position at room temperature is determined based on the relative thermal displacement, and multi-region three-dimensional dynamic alignment is performed based on the compensated undercut position. During the lamination process, the pressure and thickness changes in different areas are acquired in real time, and the lamination pressure is dynamically adjusted based on the deviation of local pressure from the average pressure and the rate of thickness change. When it is detected that a local area has formed a contact pressure higher than other areas in advance, the pressure increase is paused and the current temperature and pressure state is maintained until the pressure difference between the local area and other areas returns to the preset allowable range before the pressure is increased again. After lamination is completed, the cooling rate is controlled according to the thickness change rate during the cooling process, and pressure is released in stages using a depressurization method. Finally, the defect category and defect location corresponding to the quality inspection results are back-linked to the process parameters of the corresponding previous process.

[0077] In this embodiment, the local thickness and initial warpage state of the copper substrate are collected in a gridded manner to establish an initial manufacturing state matrix, which serves as the parameter basis for subsequent processes.

[0078] Next, target depth control etching parameters are generated for different grid regions based on local thickness and warpage. Staged depth control etching is then performed to form depth control grid grooves. The actual processing results of the depth control etching are used as input for subsequent filling processes.

[0079] Furthermore, the actual tank volume is obtained by three-dimensional morphology detection of the depth-controlled mesh tank. Based on the actual tank volume and resin rheological state, staged vacuum resin filling is performed. During the curing process, zoned thermal compensation is performed based on the local temperature difference between the copper area and the resin area. The curing termination time of the corresponding area is determined according to the curing state of each area.

[0080] Next, the local height difference between the cured copper surface and the resin surface is collected to form a height difference map, and adaptive grinding and leveling are performed accordingly. The copper bosses are inspected for size and surface condition, error matching and grouping are performed, and pressing is performed according to the local contact state of each copper boss. During the pressing process, the pressing parameters are adjusted according to the pressing displacement change.

[0081] Next, the relative thermal displacement of copper boss 1 6 and copper boss 2 5 at the target lamination temperature is obtained, the compensation amount of the undercut position at room temperature is determined, and multi-region three-dimensional dynamic alignment is performed based on the compensated undercut position.

[0082] During the lamination process, the lamination pressure is dynamically adjusted based on the deviation of local pressure from the average pressure and the rate of thickness change. When premature contact is detected in a local area, the pressurization is paused and the current temperature and pressure are maintained. Pressurization continues after the pressure difference is restored. After lamination is completed, the cooling rate is controlled according to the thickness change rate during the cooling process, and pressure is released in a segmented depressurization manner; Finally, the defect category and defect location corresponding to the quality inspection results are back-linked to the process parameters of the corresponding previous process to form a closed-loop control.

[0083] In this embodiment, the actual detection results and actual processing results of the previous process are used as the process input parameters of the subsequent process, so that each process no longer depends on the preset fixed parameters for execution, but is adaptively adjusted based on the actual state of the copper substrate, thereby improving the matching degree between the process parameters of each process and the actual processing state. In this embodiment, the resin curing degree is made uniform by partitioned thermal compensation and partitioned curing termination, avoiding local over-curing or under-curing; adaptive grinding driven by height difference map is used to match the grinding amount with the actual error, avoiding over-grinding; thermal displacement compensation and multi-region three-dimensional dynamic alignment improve the inverted thread alignment accuracy and reduce interlayer alignment deviation; local pressure monitoring and early contact detection reduce the risk of local stress concentration; segmented pressure reduction reduces thickness rebound during pressure relief; reverse correlation of quality defects enables continuous updating of process parameters, so that the processing quality of subsequent batches is gradually improved.

[0084] In one embodiment, the steps of generating depth-controlled etching parameters and forming depth-controlled mesh grooves include: The copper substrate is supported by a three-point reference support method so that the copper substrate is in a non-forced flattening state during the testing process; Get each grid Corresponding local thickness and local warping ; According to the local thickness Determine the basic target depth control depth for the corresponding grid area. And based on the amount of local warping Determine the warpage compensation amount The target depth is obtained: ; Among them, the basic target depth control depth According to the local thickness and preset depth control ratio Sure; The local etching load is determined based on the area to be etched in each grid region and the area of ​​the corresponding grid region. The etching time or etching intensity of the corresponding grid area is adjusted according to the local etching load. During staged depth-controlled etching, the actual etching depth of each grid area is detected in real time. And calculate the remaining etching amount: ; when At that time, the first etching stage is performed; when At that time, the process switches to the second etching stage, wherein the etching intensity of the second etching stage is lower than that of the first etching stage. The preset switching threshold; When the deviation between the actual etching depth and the target control depth of each grid area, as well as the deviation of the corresponding tank sidewall inclination angle, are all within the preset allowable range, the control etching is deemed qualified and proceeds to the subsequent resin filling process; if any deviation exceeds the corresponding allowable range, compensation etching is performed on the corresponding grid area or it is marked as an abnormal area.

[0085] In this embodiment, a three-point reference support method is used to support the copper substrate. The three support points are not on the same straight line and together form a detection reference plane, so that the copper substrate is in a natural state rather than a forced flattened state during the detection process.

[0086] Non-contact detection is used to obtain information for each grid. Local thickness and local warping Based on local thickness and preset depth control ratio Determine the depth of the basic target control Based on the amount of local warping Determine the warpage compensation amount The two are superimposed to obtain the target depth control depth. This compensates for the processing reference deviation caused by the warping of the copper substrate.

[0087] The local etching load is determined based on the ratio of the area to be etched to the area of ​​the grid region. Based on this, the etching time or etching intensity of the corresponding grid area can be adjusted.

[0088] During the phased etching process, the actual etching depth of each grid area is monitored in real time. Calculate the remaining etching amount The remaining etching amount is greater than the switching threshold. The first etching stage is performed to quickly remove the copper layer. When the remaining etching amount is less than or equal to the switching threshold, the process switches to the second etching stage, which has a lower etching intensity, to improve the depth control accuracy.

[0089] After etching is completed, the actual etching depth deviation and the tank sidewall inclination angle deviation are inspected. If the deviations are within the allowable range, the process is deemed qualified and proceeds to the subsequent resin filling process. If any deviation exceeds the limit, the corresponding grid area is either compensated for etching or marked as an abnormal area.

[0090] In this embodiment, the non-forced flattening three-point reference support avoids the additional deformation introduced by forced flattening, so that the local thickness and warpage detection results reflect the true state of the copper substrate; the warpage compensation corrects the difference between the etching processing reference and the ideal plane, and improves the accuracy of the target depth control in each grid area. Local etching load correction matches the etching action with the amount of material to be etched locally, improving etching uniformity; staged etching balances processing efficiency and depth control accuracy; grids with excessive deviations undergo local compensation etching, avoiding the scrapping of the entire substrate and improving material utilization and processing yield.

[0091] In one embodiment, the staged vacuum resin filling and zoned compensation curing includes: The first obtained from 3D topography detection Actual groove volume of individual depth control grid groove Combined with the pre-obtained resin curing shrinkage rate Determine the theoretical resin filling volume for the corresponding depth-controlled mesh groove: ; Detect the viscosity of the resin at the specified temperature before filling. When the viscosity Less than or equal to the preset allowable viscosity At this time, the resin filling stage is permitted; When the viscosity is greater than the allowable viscosity, maintain or adjust the resin temperature until the viscosity meets the filling conditions. During the vacuum exhaust process, the pressure in the vacuum chamber is... The rate of change is detected when When the vacuum chamber pressure reaches a stable state, it enters the low-speed pre-filling stage. Detecting the resin front flow rate during low-speed prefilling process When the resin front flow velocity is higher than the preset upper limit or lower than the preset lower limit, the injection pressure and / or resin temperature are adjusted according to the corresponding abnormal direction. Based on the resin front flow velocity Resin viscosity Filling pressure difference and vacuum holding time Calculate the cavity risk index When the void risk index exceeds the preset risk threshold, stop increasing the amount of glue injected and re-perform vacuum venting; The partitioned compensation curing process includes: detecting the temperature of the copper area in different regions. and resin zone temperature Calculate the local temperature difference in the corresponding area: , when Exceeding the preset temperature difference allowable value At that time, thermal compensation is performed on the corresponding area; and based on the curing state parameters of the corresponding area... Determine whether the area has met the preset curing termination conditions. When the curing termination condition is met, heating of the corresponding area is stopped or the heat input to the corresponding area is reduced, while areas that have not met the curing termination condition continue to cure.

[0092] In this embodiment, the first [item] obtained from the three-dimensional topography detection [is...]. Actual groove volume of individual depth control grid groove and resin curing shrinkage rate Calculate the theoretical resin filling volume This ensures that the resin filling amount matches the actual tank volume and allows for curing shrinkage allowance.

[0093] Detect the viscosity of the resin at the specified temperature before filling. Viscosity less than or equal to the preset allowable viscosity When the viscosity is too high, the resin temperature is maintained or adjusted until the viscosity meets the filling requirements.

[0094] Detecting the pressure in the vacuum chamber during vacuum exhaust process The rate of change of pressure, the absolute value of which is less than or equal to the preset value. Once the vacuum pressure is determined to be stable, the system then enters a low-speed pre-filling stage.

[0095] Detecting the resin front flow rate during prefilling When the flow rate is higher than the upper limit, reduce the injection pressure or adjust the resin temperature. When the flow rate is lower than the lower limit, adjust the injection pressure or resin temperature according to the resin viscosity.

[0096] Based on the resin front flow rate resin viscosity Filling pressure difference Calculate the void risk index using the vacuum holding time t_v When the indicator exceeds the preset risk threshold, stop increasing the amount of adhesive and restart vacuum degassing.

[0097] During the curing stage, the temperature of the copper area in different regions was measured. and resin zone temperature Calculate local temperature difference The absolute value of the temperature difference exceeds the preset allowable temperature difference value. Thermal compensation is applied to the corresponding area at that time; Based on the curing state parameters of each region The curing degree is determined, and heating is stopped or the heat input is reduced in areas that have reached the preset curing termination condition, while areas that have not reached the curing termination condition continue to cure.

[0098] In this embodiment, the resin filling amount is calculated based on the actual tank volume, avoiding underfilling or overfilling caused by the deviation between the theoretical volume and the actual tank volume; viscosity access control ensures that the resin is filled in a suitable rheological state, reducing the risk of filling defects; Vacuum pressure stability assessment and low-speed pre-filling reduce the probability of resin air entrapment; real-time resin front flow velocity monitoring and void risk index calculation make void risk controllable, and timely stop injection and re-venting when risk exceeds limit. The zoned thermal compensation reduces the temperature difference between the copper zone and the resin zone, and the zoned curing termination avoids local over-curing, resulting in uniform curing quality.

[0099] In one embodiment, the adaptive grinding and leveling and copper boss pressing includes: acquiring three-dimensional height data of the copper surface and the resin surface, calculating the height difference between the copper surface height and the resin surface height at each location, and forming a local error map based on the deviation between the height difference and the target plane. ; The local error map is used to determine the area to be ground, the non-ground area, and the grinding amount corresponding to each area to be ground, and the local error map is re-detected after each grinding cycle. When the error change in the corresponding area is less than the preset convergence threshold in two consecutive grinding cycles, the corresponding area is determined to have reached the leveling state and the grinding of the corresponding area is stopped. In the region of the resin tank with directional extension structures, the grinding direction is controlled. Oriented towards the resin tank Maintain a preset angle range between them to reduce the continuous dragging effect along the direction of the resin tank; Before the copper bosses are pressed together, the length, width, height, contact area and surface roughness of each copper boss are measured, and a set of characteristic parameters for the corresponding copper bosses is established. Copper bosses with the same or similar allowable range of size deviation and surface condition are grouped according to the set of characteristic parameters, and corresponding pressing parameters are set for different groups; For the A copper boss is used, and the initial pressing pressure is determined based on the height difference between the copper boss and the surface to be connected, the actual contact area, and the surface roughness. , Among them, when the height difference or surface roughness increases while other conditions remain the same, the corresponding target pressing pressure is increased; When the effective contact area is reduced while other conditions remain the same, the corresponding target pressing pressure is reduced to limit the local load per unit contact area. Real-time monitoring of the pressing displacement of the copper bosses during the pressing process. And calculate the rate of change of the compression displacement: ; When the rate of change of the pressing displacement increases by more than a preset threshold relative to the previous pressing stage, it is determined that the corresponding copper boss has undergone rapid compression or premature local contact, and the pressing pressure is suspended from being increased further. Once the rate of change of the pressing displacement returns to the preset stable range and the pressing pressure is stable, the pressure holding stage begins.

[0100] In this embodiment, three-dimensional height data of the copper surface and resin surface are collected, the difference between the height of the copper surface and the height of the resin surface at each location is calculated, and a local error map is generated based on the deviation of the height difference from the target plane. .

[0101] The grinding area, non-grinding area, and grinding amount corresponding to each grinding area are determined based on the error map. After each grinding cycle, the error map is re-detected. When the error change of the corresponding area is less than the preset convergence threshold in two consecutive grinding cycles, the area is determined to have reached the leveling state and grinding is stopped.

[0102] For areas of the resin tank with directional extension structures, control the grinding direction. Orientation relative to resin tank Maintain a preset angle range between them to reduce the continuous dragging effect along the resin tank direction.

[0103] Before pressing the copper bosses, the length, width, height, contact area, and surface roughness of each copper boss are measured to establish a set of characteristic parameters. Copper bosses with the same or similar allowable range of dimensional deviation and surface condition are grouped, and corresponding pressing parameters are set for different groups.

[0104] For the The initial pressing pressure is determined based on the height difference between the copper boss and the surface to be joined, the actual contact area, and the surface roughness. Increase the target pressing pressure when the height difference or surface roughness increases, and decrease the target pressing pressure when the effective contact area decreases in order to limit the local load per unit contact area.

[0105] Real-time monitoring of the pressing displacement of the copper bosses during the pressing process. Calculate the rate of change of compression displacement When the rate of compression exceeds the preset change threshold, it is determined that the copper boss has undergone rapid compression or premature contact in some areas, and the compression pressure is suspended. After the rate of compression returns to the preset stable range and the compression pressure stabilizes, the pressure holding stage begins.

[0106] In this embodiment, adaptive grinding is performed using an error map to match the grinding amount with the actual height difference. Through convergence judgment, over-grinding is avoided, thereby improving leveling accuracy and processing efficiency. By maintaining an angle between the grinding direction and the resin tank direction, continuous dragging along the tank direction is reduced, thus minimizing damage to the resin tank edge. Grouping of copper bosses and differentiated pressing parameters enable the pressing process to match the actual state of each boss, thereby improving the uniformity of pressing. The initial pressing pressure is adaptively determined based on the height difference, contact area, and roughness, which limits the load per unit area and avoids local overload. The detection of sudden increases in compression displacement rate can promptly identify rapid compression and premature local contact, preventing compression damage and improving the consistency of compression quality.

[0107] In one embodiment, the undercut position pre-compensation, dynamic alignment, lamination pressure adjustment, and cooling pressure relief include: The target lamination temperature was determined for copper boss 1-6 and copper boss 2-5 respectively. The relative thermal displacement between copper boss 16 and copper boss 25 was obtained by thermal response detection. and ; The inverted target position at room temperature is determined based on the relative thermal displacement: , in, and These are the inverted target positions at the target lamination temperature; During the room temperature alignment process, the actual three-dimensional coordinates of multiple undercut feature points on copper boss 16 and copper boss 25 are obtained simultaneously, and the translational deviation, rotational deviation and local position deviation are calculated based on the coordinate deviation of multiple undercut feature points. When all deviations are within the corresponding preset allowable range, it is determined that the two boss plates have met the lamination alignment conditions. During the lamination process, local pressure in multiple areas is monitored in real time. And the change in plate thickness, and calculate the average pressure. ; When any local region satisfies: If the pressure in the adjacent areas of the local area does not reach the corresponding pressure level synchronously, it is determined that the local area has premature contact. The pressure increase is paused and the current temperature is maintained until the pressure difference between the local area and the adjacent area is restored to the preset allowable range before the pressure is increased again. Continuous monitoring of laminate thickness during cooling process And calculate the thickness change rate. When the absolute value of the thickness change rate exceeds a preset change rate threshold, the cooling rate is reduced and a slow cooling state is entered. During the depressurization process, at least two pressure reduction stages are used for segmented pressure reduction, and the change in laminate thickness is detected after each pressure reduction stage is completed. When the thickness rebound amount corresponding to any pressure reduction stage exceeds the preset allowable value, continue depressurization and maintain the current pressure. Continue to the next pressure reduction stage after the thickness change returns to the allowable range. After lamination, the multilayer board is inspected for flatness, interlayer alignment deviation, resin filling defects, and boss connection status. The detected defect types, defect locations, and corresponding defect degrees are then correlated with the process parameters used in the previous process to update the process parameters for the corresponding processes in subsequent batches.

[0108] In this embodiment, the target lamination temperature is set for copper boss 6 and copper boss 5, respectively. Thermal response detection was performed to obtain the relative thermal displacement between the two plates. and , The inverted target position at room temperature is calculated based on the relative thermal displacement. and Pre-compensation is performed on the undercut position at the target lamination temperature.

[0109] During the room temperature alignment process, the actual three-dimensional coordinates of multiple inverted feature points on the two bosses are obtained simultaneously. The translational deviation, rotational deviation, and local positional deviation are calculated based on the coordinate deviation. When each deviation is within the corresponding preset allowable range, the two bosses are determined to have met the lamination alignment conditions.

[0110] During the lamination process, local pressure in multiple areas is monitored in real time. Calculate the average pressure based on the change in plate thickness. ; When the local pressure is greater than the average pressure plus the allowable deviation If the pressure in adjacent areas does not reach the corresponding pressure level synchronously, it is determined that there is premature contact in the local area, and the increase of lamination pressure is paused and the current temperature is maintained. The pressure will continue to increase after the pressure difference is restored to the preset allowable range.

[0111] Continuous monitoring of laminate thickness during cooling process It also calculates the thickness change rate, and when the absolute value of the rate exceeds the preset change rate threshold, it reduces the cooling rate and enters a slow cooling state.

[0112] During the depressurization process, at least two pressure reduction stages are used for segmented pressure reduction. After each pressure reduction stage is completed, the change in laminate thickness is detected. If the thickness rebound exceeds the preset allowable value, the depressurization is paused and the current pressure is maintained. The next pressure reduction stage is continued after the thickness change returns to the allowable range.

[0113] After lamination, the flatness, interlayer alignment deviation, resin filling defects and boss connection status of the multilayer board are inspected. The defect type, defect location and defect degree are linked with the process parameters of the previous process and the process parameters of the corresponding process in the subsequent batch are updated.

[0114] In this embodiment, thermal response detection and room temperature undercut position pre-compensation eliminate the influence of the relative thermal displacement of the two plates on the undercut alignment accuracy during the heating process. Multi-feature point three-dimensional alignment simultaneously corrects translational deviation, rotational deviation and local position deviation, thereby improving the lamination alignment accuracy. By conducting early contact detection and pausing pressurization, localized stress concentrations were avoided when the layers were not yet in uniform contact; and slow cooling by controlling the thickness change rate reduced abnormal thickness changes during the cooling process. By using segmented pressure reduction combined with thickness rebound detection, interlayer separation caused by excessive pressure release is avoided; by inversely correlating quality defects with the process parameters of the previous process, the process parameters can be continuously optimized for defect categories, thereby improving the yield of subsequent batches of products.

[0115] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A multilayer board with copper substrate and inverted boss copper busbars laminated together, characterized in that, include: The first boss plate has a grid partition formed on its front side using resin. The second boss plate has a grid partition formed on the back by resin; The back of the second boss plate interlocks with the front of the first boss plate to form a multi-layer board; Among them, the first boss plate is provided with a copper boss (6).

2. The multilayer board with copper substrate inverted boss copper busbars laminated as described in claim 1, characterized in that, The first boss plate includes: a copper substrate one (1), the front side of which is pressed together with a copper substrate two (2) through a dielectric layer one (3), and a copper boss one (6) is provided on the copper substrate two (2). The second boss plate includes: a copper substrate three (8), the back side of which is pressed together with a copper substrate two (2) through a dielectric layer two (4), and is disposed on the front side of a copper substrate one (1) at intervals from the copper substrate two (2); The back side of the copper substrate 3 (8) is provided with copper boss 2 (5), and the copper boss 2 (5) is pressed onto the front side of the copper substrate 2 (2) through dielectric layer 2 (4).

3. The multilayer board with copper substrate inverted boss copper busbars laminated as described in claim 2, characterized in that, The copper substrate three (8) is provided with slots; and the upper surfaces of the copper substrate two (2), the dielectric layer two (4) and the copper substrate three (8) are on the same horizontal plane, and the same horizontal plane is provided with an electroplating layer (7).

4. A multilayer board manufacturing process, applicable to a multilayer board with copper substrate undercut boss copper busbars laminated as described in any one of claims 1-3, characterized in that, The multilayer board with copper substrate undercut boss copper busbars is obtained by multilayer board manufacturing process, which includes: The front side of the copper substrate (1) is etched with controlled depth to form a controlled depth groove on the front side of the copper substrate (1); the controlled depth groove is filled with resin so that the filled resin forms multiple grid partitions on the front side of the copper substrate (1); the resin on the surface of the grid partition is ground so that the resin surface is flush with the opening end face of the controlled depth groove or flush with the front side of the copper substrate (1). The back side of the copper substrate three (8) is etched with controlled depth to form a controlled depth groove on the back side of the copper substrate three (8), and the controlled depth groove is filled with resin; the resin on the back side of the copper substrate three (8) is ground so that the resin surface is flush with the opening end face of the controlled depth groove, or flush with the back side of the copper substrate three (8); a copper boss one (6) is formed on the front side of the copper substrate one (1), and a copper boss two (5) is formed on the back side of the copper substrate three (8). An insulating thermally conductive medium layer is pressed onto the front side of copper substrate one (1) and the back side of copper substrate three (8) respectively, so that the insulating thermally conductive medium layer is flush with the upper surface of copper boss one (6) and the surface of copper boss two (5) respectively. The back side of copper substrate three (8) is flipped onto the front side of copper substrate one (1), and the copper substrate three (8), copper substrate one (1), insulating thermal conductive medium layer, copper boss one (6) and copper boss two (5) are pressed together to form a multilayer board.

5. The multilayer board manufacturing process as described in claim 4, characterized in that, The depth of the controlled etching on the front side of the copper substrate one (1) is half the thickness of the copper substrate one (1), and the depth of the controlled etching on the back side of the copper substrate three (8) is half the thickness of the copper substrate three (8). The depth control groove on the front side of the copper substrate one (1) is filled with resin to form intersecting grid partitions, and the depth control groove on the back side of the copper substrate three (8) is filled with resin to form intersecting grid partitions. The copper substrate one (1) and copper substrate three (8) respectively divide the corresponding copper substrate surface into multiple mutually separated regions through the grid partition.

6. The multilayer board manufacturing process as described in claim 4, characterized in that, The method for forming the copper boss (6) includes: At least two etching operations are performed on the front side of the copper substrate 1 (1) to form an etching depth control area on the front side of the copper substrate 1 (1) for accommodating the copper boss 1 (6). The copper boss (6) is pressed into the etching depth control area; The resin protruding from the front of the copper substrate (1) after lamination is ground so that the upper surface of the copper boss (6) is flush with the adjacent insulating and thermally conductive dielectric layer.

7. The multilayer board manufacturing process as described in claim 6, characterized in that, The method for forming the copper boss 2 (5) includes: At least two etching operations are performed on the back side of the copper substrate three (8) to form an etching depth control area on the back side of the copper substrate three (8) for accommodating the copper boss two (5). The copper boss 2 (5) is pressed into the etching depth control area; The resin protruding from the back of the copper substrate three (8) after lamination is ground so that the surface of the copper boss two (5) is flush with the adjacent insulating and thermally conductive dielectric layer. The etching depth on the back side of the copper substrate three (8) corresponds to the thickness of the copper substrate one (1), and the thickness of the copper boss two (5) corresponds to the thickness of the copper substrate one (1). The thickness of the copper boss (6) corresponds to the thickness of the copper substrate (1); After copper substrate three (8) and copper substrate one (1) are pressed together by inverted bonding, copper boss one (6) and copper boss two (5) respectively form copper conductive paths for transmitting large current.

8. The multilayer board manufacturing process as described in claim 7, characterized in that, . The insulating thermally conductive medium layer is a PP insulating thermally conductive adhesive layer with a thickness of 0.1 mm; The thickness of the copper substrate (1) is not less than 0.5 mm; The copper substrate one (1) or copper substrate three (8) is provided with slots, which are located between copper bosses or on the side of the copper bosses away from the insulating thermally conductive medium layer. The slots are used to form heat dissipation channels, or to fill the slots with heat dissipation material to form a heat dissipation structure; After the interconnection areas of the first copper substrate (1), the second copper substrate (2), the dielectric layer and the third copper substrate (8) are formed into a plane, an electroplating layer (7) is provided on the plane to form a conductive connection area for transmitting small currents.

9. The multilayer board manufacturing process as described in claim 5, characterized in that, Also includes: The local thickness and initial warpage state of the copper substrate are collected in a gridded manner, and an initial manufacturing state matrix containing local thickness and local warpage is established. Based on the local thickness and the local warpage, corresponding target depth control etching parameters are generated for different mesh regions, and staged depth control etching is performed according to the target depth control etching parameters to form depth control mesh grooves. Three-dimensional morphology detection is performed on the etched depth control grid grooves to obtain the actual groove volume of each depth control grid groove, and staged vacuum resin filling is performed according to the actual groove volume and resin rheological state; during the resin curing process, zoned thermal compensation is performed according to the local temperature difference between the copper area and the resin area, and the curing termination time of the corresponding area is determined according to the curing state of each area. The local height difference between the cured copper surface and the resin surface is collected to form a height difference map, and adaptive grinding and leveling are performed based on the height difference map; the size and surface condition of the copper bosses to be pressed are detected, error matching and grouping are performed according to the detection results, and pressing is performed according to the local contact state of each copper boss. During the pressing process, the pressing parameters are adjusted according to the pressing displacement change state.

10. The multilayer board manufacturing process according to claim 9, characterized in that, The relative thermal displacements of copper boss one (6) and copper boss two (5) at the target lamination temperature are obtained respectively. The compensation amount of the undercut position under room temperature is determined based on the relative thermal displacement, and multi-region three-dimensional dynamic alignment is performed based on the compensated undercut position. During the lamination process, the pressure and thickness changes in different areas are acquired in real time, and the lamination pressure is dynamically adjusted based on the deviation of local pressure from the average pressure and the rate of thickness change. When it is detected that a local area has formed a contact pressure higher than other areas in advance, the pressure increase is paused and the current temperature and pressure state is maintained until the pressure difference between the local area and other areas returns to the preset allowable range before the pressure is increased again; after lamination is completed, the cooling rate is controlled according to the thickness change rate during the cooling process, and the pressure is depressurized by segmented pressure reduction; finally, the defect category and defect location corresponding to the quality inspection results are back-linked to the process parameters of the corresponding previous process.

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