Multi-substrate laminated packaging structure and method based on kovar column array

Abstract

The invention provides a multi-substrate laminated packaging structure and method based on a kovar column array, and the structure comprises a plurality of groups of substrate units which are repeatedly stacked in the vertical direction, each substrate unit comprises a lower substrate which is horizontally disposed, the top of the lower substrate is uniformly provided with a plurality of kovar columns in an array manner, and the central axis of each kovar column is vertically disposed; a kovar frame is further arranged at the top of the lower-layer base plate, a plurality of kovar columns are arranged in the kovar frame, an upper-layer base plate is further arranged at the tops of the kovar columns, and the upper-layer base plate is parallel to the lower-layer base plate; in the stacked substrate units, the lower-layer substrate of each substrate unit is the upper-layer substrate of the lower adjacent substrate unit, and the upper-layer substrate of each substrate unit is the lower-layer substrate of the upper adjacent substrate unit. According to the structure, electrical interconnection and structural supporting of different layers of substrates are achieved at the same time through the kovar columns, the expandability of the structure is high, multi-layer stacking can be conducted in the vertical direction according to actual needs, and the packaging size is effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic product production, relates to substrate stacked packaging, and specifically relates to a multi-substrate stacked packaging structure and method based on a kovar post array. Background Art

[0002] POP (Package on Package) is one of the important system-level packaging structures. Chips with different functions are respectively packaged in different packages to form packaged devices, and the packaged devices are stacked on top of another packaged device to achieve high integration and miniaturization of the packaging. Conventional POP packaging interconnects the bottom module and the top module through solder balls, usually in a plastic package structure, which cannot meet the usage requirements when the product has airtightness requirements.

[0003] In an integrated temperature control module, multiple temperature control circuits need to be integrated into an airtight packaging structure, and there are a large number of chips and passive components in the module. If a two-dimensional packaging form is used, the miniaturization requirement of the product cannot be met; if a traditional POP packaging form is used, the airtightness requirement of the product cannot be met. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, an object of the present invention is to provide a multi-substrate stacked packaging structure and method based on a kovar post array to solve the technical problem that it is difficult to simultaneously take into account the packaging density and the airtightness of the structure in the existing technology.

[0005] To solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0006] A multi-substrate stacked packaging structure based on a kovar post array includes multiple groups of substrate units repeatedly stacked vertically. Each substrate unit includes a horizontally arranged lower substrate, and a plurality of kovar posts are uniformly arranged in an array on the top of the lower substrate. The central axis of each kovar post is arranged vertically. A kovar frame is also arranged on the top of the lower substrate, and the plurality of kovar posts are arranged inside the kovar frame; an upper substrate is also arranged on the top of the kovar posts, and the upper substrate and the lower substrate are parallel.

[0007] In the stacked substrate units, the lower substrate of a substrate unit is the upper substrate of the adjacent substrate unit below, and the upper substrate of a substrate unit is the lower substrate of the adjacent substrate unit above.

[0008] The present invention also has the following technical features:

[0009] Specifically, a plurality of device lead-out terminals are arranged at the bottom of the lower substrate in the substrate unit located at the lowermost layer.

[0010] The present invention also protects a multi-substrate stacked packaging method based on a kovar post array as described above, which uses the multi-substrate stacked packaging structure based on a kovar post array as described above.

[0011] This method uses a kovar post assembly tooling and a dedicated stacking tooling for packaging.

[0012] Specifically, the kovar post assembly tooling includes a horizontally arranged tooling bottom plate. At the center of the upper surface of the tooling bottom plate, a tooling bottom plate groove is opened, and the size of the tooling bottom plate groove is equal to the size of the lower substrate. On the left and right sides of the tooling bottom plate, tooling bottom plate positioning holes penetrating through the upper and lower ends are respectively opened.

[0013] The kovar post assembly tooling also includes a horizontally arranged tooling stencil. The tooling stencil is located on top of the tooling bottom plate. Along the transverse direction at the center of the tooling stencil, a plurality of kovar post perforations are evenly arranged. Each kovar post perforation penetrates through the upper and lower ends of the tooling stencil, and the diameter of each kovar post perforation is equal to the diameter of the kovar post. On the left and right sides of the tooling stencil, tooling stencil positioning holes penetrating through the upper and lower ends are respectively opened, and the tooling stencil positioning holes and the tooling bottom plate positioning holes are vertically corresponding one by one.

[0014] In each tooling stencil positioning hole and the corresponding tooling bottom plate positioning hole at the vertical bottom, the same kovar post assembly positioning pin is arranged.

[0015] Specifically, the dedicated stacking tooling includes a horizontally arranged bottom layer plate. At the center of the upper surface of the bottom layer plate, a bottom layer plate groove is opened, and the size of the bottom layer plate groove is equal to the size of the lower substrate. On the left and right sides of the bottom layer plate, bottom layer plate positioning holes penetrating through the upper and lower ends are also opened.

[0016] The dedicated stacking tooling also includes a horizontally arranged upper layer plate. The upper layer plate is located on top of the bottom layer plate. At the center of the lower surface of the upper layer plate, upper layer plate grooves are opened, and the size of the upper layer plate grooves is equal to the size of the upper substrate. On the left and right sides of the upper layer plate, upper layer plate positioning holes penetrating through the upper and lower ends are also opened, and the upper layer plate positioning holes and the bottom layer plate positioning holes are vertically corresponding one by one.

[0017] In each bottom layer plate positioning hole and the corresponding upper layer plate positioning hole at the vertical top, the same positioning pin is arranged.

[0018] Preferably, this method specifically includes the following steps:

[0019] Step 1, using the kovar post assembly tooling, place the lower substrate at the tooling bottom plate groove, and use a thermal release adhesive for bonding. Then, place kovar post solder pads at all positions on the surface of the lower substrate where the kovar posts need to be arranged.

[0020] Meanwhile, place the upper substrate in the upper board groove of the upper board in the dedicated lamination tooling, and use heat-release glue for cementing. Then, place the kovar frame solder pads at the positions where the kovar frames need to be arranged on the surface of the upper substrate.

[0021] Step 2: Using the kovar post assembly tooling, place multiple kovar posts at all the positions on the surface of the lower substrate where the kovar post solder pads are arranged. Meanwhile, using the dedicated lamination tooling, place the kovar frames at all the positions on the surface of the upper substrate where the kovar frame solder pads are arranged.

[0022] Step 3: Weld between the lower substrate and the multiple kovar posts to obtain the processed lower substrate, and weld between the upper substrate and the kovar frames to obtain the processed upper substrate. After welding, perform atomization cleaning on all the solder joints, and respectively assemble and weld the passive components and chips inside the processed lower substrate and the processed upper substrate to obtain the assembled lower substrate and the assembled upper substrate.

[0023] Step 4: Place the kovar post solder pads on the top of each kovar post in the assembled upper substrate obtained in Step 3, and place the kovar frame solder pads at the positions where the kovar frames need to be arranged on the surface of the assembled lower substrate obtained in Step 3. Then, using the dedicated lamination tooling, align and weld between the assembled lower substrate and the assembled upper substrate. The kovar posts and kovar frames are placed between the assembled lower substrate and the assembled upper substrate, and the kovar posts are placed inside the kovar frames to obtain the lowermost substrate unit.

[0024] Step 5: Use the upper surface of the upper substrate in the lowermost substrate unit obtained in Step 4 as the upper surface of the lower substrate in the upper substrate unit of the next layer, and repeat Steps 1 to 4 to obtain multiple substrate units stacked vertically in repetition.

[0025] Step 6: Weld multiple device lead-out terminals to the bottom of the lower substrate in the lowermost substrate unit to obtain the multi-substrate stacked packaging structure.

[0026] In Step 1, the materials of the lower substrate and the upper substrate are ceramic substrates, and the ceramic substrates include alumina ceramic substrates, aluminum nitride ceramic substrates, and silicon carbide ceramic substrates.

[0027] The diameter of the pad corresponding to the kovar post is (1.2 - 1.6) × the diameter of the kovar post.

[0028] The width of the pad corresponding to the kovar frame is (1.2 - 1.6) × the wall thickness of the kovar frame.

[0029] The diameter of the kovar post is 0.3 mm - 0.8 mm, and the height of the kovar post is 1 mm - 3 mm.

[0030] The Kovar column solder tab is 0.01 mm to 0.025 mm thinner than the Kovar frame solder tab.

[0031] In step two, the materials of both the Kovar column and the Kovar frame are 4J29 Kovar alloy.

[0032] The surfaces of the Kovar column and the Kovar frame are evenly distributed with a coating, and the coating is nickel-gold.

[0033] The height of the Kovar frame is 0.02 mm to 0.05 mm less than the height of the Kovar column.

[0034] In step three, the welding method is reflow welding or vacuum eutectic welding.

[0035] The models of the solder tabs used in the welding process are all Au80Sn20 solder tabs, and the thickness of the solder tabs is 0.05 mm to 0.2 mm.

[0036] In step four, the atmosphere in the soldering tool during soldering is nitrogen.

[0037] Compared with the prior art, the present invention has the following technical effects:

[0038] (Ⅰ) In the multi-substrate stacked package structure of the present invention, the Kovar column is used to simultaneously achieve electrical interconnection and structural support of different layers of substrates, and the structure has strong scalability and can be stacked in multiple layers in the vertical direction according to actual needs, effectively reducing the package size, significantly improving the internal package density of the device, and realizing low-cost, airtight and highly reliable vertical interconnection inside the device.

[0039] (Ⅱ) In the method of the present invention, a Kovar column assembly tooling and a stacked special tooling are used for high-precision integrated soldering of the Kovar column and the Kovar frame, ensuring the position accuracy and height consistency of the Kovar column and the Kovar frame, which not only ensures electrical interconnection but also ensures the airtightness of the overall structure.

[0040] (Ⅲ) The method of the present invention uses a Kovar column for connection. Compared with the large difference in thermal expansion coefficients between the substrate and the connection column and the adverse effects of the plastic package structure caused by using a micro copper column for connection, the good compatibility between the Kovar column and the ceramic substrate makes this method promising to be applied in highly reliable aerospace products. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the overall structure of the double-substrate stacked package structure of the present invention.

[0042] Figure 2 It is a schematic diagram of the overall perspective structure of the double-substrate stacked package structure of the present invention.

[0043] Figure 3Schematic diagram of the structure of the kovar column and the solder tab at the kovar frame in the present invention.

[0044] Figure 4 Schematic flow chart of the method for the multi-substrate stacked packaging structure of the present invention.

[0045] Figure 5 Schematic diagram of the structure during the assembly of the kovar column in the present invention.

[0046] Figure 6 Schematic diagram of the structure during the assembly of the multi-substrate stacked packaging structure of the present invention.

[0047] The meanings of the various reference numerals in the figure are as follows: 1 - substrate unit, 2 - device lead-out terminal, 3 - kovar column solder tab, 4 - kovar frame solder tab, 5 - passive component, 6 - chip, 7 - bottom layer board, 8 - bottom layer board groove, 9 - upper layer board, 10 - upper layer board groove, 11 - bottom layer board positioning hole, 12 - upper layer board positioning hole, 13 - positioning pin, 14 - interconnecting wire, 15 - tooling bottom board, 16 - tooling bottom board groove, 17 - tooling stencil, 18 - tooling bottom board positioning hole, 19 - kovar column through hole, 20 - tooling stencil positioning hole, 21 - kovar column assembly positioning pin.

[0048] 101 - lower substrate, 102 - kovar column, 103 - kovar frame, 104 - upper substrate.

[0049] The specific content of the present invention will be further described in detail below in conjunction with the drawings and embodiments. Specific embodiments

[0050] It should be noted that all the components, materials, methods and devices in the present invention, unless otherwise specified, are all the components, materials, methods and devices known in the prior art. For example, the device lead-out terminal uses a known device lead-out terminal, nickel-gold uses known nickel-gold, the thermal release adhesive uses a known thermal release adhesive, the reflow soldering method uses a known reflow soldering method, and the soldering device uses a known soldering device.

[0051] In the present invention, the OXYZ coordinate system is a three-dimensional rectangular coordinate system. The X-axis is the horizontal direction, and the direction of the X-axis is to the right; the Y-axis is the vertical direction, and the direction of the Y-axis is upward; the Z-axis is the longitudinal direction, and the direction of the Z-axis is backward.

[0052] Following the above technical solutions, the specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of the present application fall within the protection scope of the present invention.

[0053] Embodiment 1:

[0054] This embodiment provides a multi-substrate stacked packaging structure based on a kovar column array, as Figure 1 andFigure 2 As shown, it includes multiple groups of substrate units 1 stacked repeatedly in the vertical direction. Each substrate unit 1 includes a lower substrate 101 arranged horizontally. A plurality of kovar posts 102 are uniformly arranged in an array on the top of the lower substrate 101. The central axis of each kovar post 102 is arranged vertically. A kovar frame 103 is also arranged on the top of the lower substrate 101. The plurality of kovar posts 102 are arranged inside the kovar frame 103; an upper substrate 104 is also arranged on the top of the kovar post 102. The upper substrate 104 and the lower substrate 101 are parallel.

[0055] As Figure 1 and Figure 2 shown, in the stacked substrate units 1, the lower substrate 101 of the substrate unit 1 is the upper substrate 104 of the adjacent substrate unit 1 below, and the upper substrate 104 of the substrate unit 1 is the lower substrate 101 of the adjacent substrate unit 1 above.

[0056] As a preferred solution of this embodiment, as Figure 1 and Figure 2 shown, a plurality of device lead-out terminals 2 are arranged at the bottom of the lower substrate 101 in the lowermost substrate unit 1.

[0057] Embodiment 2:

[0058] This embodiment provides a multi-substrate stacked packaging method based on a kovar post array. This method adopts the multi-substrate stacked packaging structure based on a kovar post array in Embodiment 1. As Figure 4 shown, this method specifically includes the following steps:

[0059] Step 1, as Figure 5 shown, using a kovar post assembly tooling, place the lower substrate 101 in the tooling bottom plate groove 16 and fix it with a thermal release adhesive. Then place kovar post solder pads 3 at all positions on the surface of the lower substrate 101 where the kovar posts 102 need to be arranged.

[0060] At the same time, place the upper substrate 104 in the upper plate groove 10 of the upper plate 9 in the stacking special tooling and fix it with a thermal release adhesive. Then place kovar frame solder pads 4 at the positions on the surface of the upper substrate 104 where the kovar frame 103 needs to be arranged.

[0061] In Step 1, as Figure 5 shown, the kovar post assembly tooling includes a horizontally arranged tooling bottom plate 15. A tooling bottom plate groove 16 is opened at the center of the upper surface of the tooling bottom plate 15. The size of the tooling bottom plate groove 16 is equal to the size of the lower substrate 101. Tooling bottom plate positioning holes 18 penetrating through the upper and lower ends are respectively opened on the left and right sides of the tooling bottom plate 15.

[0062] As Figure 5As shown in the figure, the Kovar column assembly tooling further includes a horizontally arranged tooling leakage plate 17. The tooling leakage plate 17 is located at the top of the tooling bottom plate 15. A plurality of Kovar column perforations 19 are evenly arranged along the transverse direction at the center of the tooling leakage plate 17. Each Kovar column perforation 19 penetrates through the upper and lower ends of the tooling leakage plate 17. The diameter of each Kovar column perforation 19 is equal to the diameter of the Kovar column 102. Tooling leakage plate positioning holes 20 penetrating through the upper and lower ends are respectively formed on the left and right sides of the tooling leakage plate 17. The tooling leakage plate positioning holes 20 and the tooling bottom plate positioning holes 18 are vertically corresponding one by one.

[0063] As Figure 5 shown in the figure, a same Kovar column assembly positioning pin 21 is arranged in each tooling leakage plate positioning hole 20 and the corresponding tooling bottom plate positioning hole 18 at the vertical bottom.

[0064] In step one, as Figure 6 shown in the figure, the lamination special tooling includes a horizontally arranged bottom layer plate 7. A bottom layer plate groove 8 is formed at the center of the upper surface of the bottom layer plate 7. The size of the bottom layer plate groove 8 is equal to the size of the lower substrate 101. Tooling bottom layer positioning holes 11 penetrating through the upper and lower ends are further formed on the left and right sides of the bottom layer plate 7.

[0065] As Figure 6 shown in the figure, the lamination special tooling further includes a horizontally arranged upper layer plate 9. The upper layer plate 9 is located at the top of the bottom layer plate 7. Upper layer plate grooves 10 are respectively formed at the centers of the lower surfaces of the upper layer plate 9. The size of the upper layer plate grooves 10 is equal to the size of the upper substrate 104. Tooling upper layer positioning holes 12 penetrating through the upper and lower ends are further formed on the left and right sides of the upper layer plate 9. The tooling upper layer positioning holes 12 and the tooling bottom layer positioning holes 11 are vertically corresponding one by one.

[0066] As Figure 6 shown in the figure, a same positioning pin 13 is arranged in each tooling bottom layer positioning hole 11 and the corresponding tooling upper layer positioning hole 12 at the vertical top.

[0067] In step one, the materials of the lower substrate 101 and the upper substrate 104 are alumina ceramic substrates.

[0068] The diameter of the pad corresponding to the Kovar column 102 is 1.3 × the diameter of the Kovar column 102.

[0069] The width of the pad corresponding to the Kovar frame 103 is 1.3 × the wall thickness of the Kovar frame 103.

[0070] The diameter of the Kovar column 102 is 0.5 mm, and the height of the Kovar column 102 is 2 mm.

[0071] As Figure 3 shown in the figure, the Kovar column solder sheet 3 is 0.02 mm thinner than the Kovar frame solder sheet 4.

[0072] In this embodiment, the kovar column assembly positioning pin 21 realizes the positioning and assembly between the kovar column 102 and the lower substrate 101.

[0073] In this embodiment, the tooling stencil positioning holes 20 and the tooling base plate positioning holes 18 correspond to each other one by one in the vertical direction, that is, the central axis of the left tooling stencil positioning hole 20 and the central axis of the left tooling base plate positioning hole 18 are collinear; the central axis of the right tooling stencil positioning hole 20 and the central axis of the right tooling base plate positioning hole 18 are collinear.

[0074] In this embodiment, the kovar column array position design adopts a known kovar column array position design.

[0075] In this embodiment, the alumina ceramic substrate ensures airtightness and guarantees the application ability of the multi-substrate stacked packaging structure in high-reliability aerospace products.

[0076] In this embodiment, the kovar column solder pad 3 is 0.02 mm thinner than the kovar frame solder pad 4, ensuring sufficient contact between the internal kovar column 102 and the alumina ceramic substrates on the upper and lower sides during assembly. After welding, the overall kovar frame 103 realizes airtight fusion sealing.

[0077] Step two, as Figure 5 shown, using the kovar column assembly tooling, place multiple kovar columns 102 at all the positions where the kovar column solder pads 3 are arranged on the surface of the lower substrate 101. At the same time, using the special stacking tooling, place the kovar frame 103 at all the positions where the kovar frame solder pads 4 are arranged on the surface of the upper substrate 104.

[0078] In step two, the materials of the kovar column 102 and the kovar frame 103 are both 4J29 kovar alloy.

[0079] The surfaces of the kovar column 102 and the kovar frame 103 are evenly provided with a coating, and the coating is nickel-gold.

[0080] The height of the kovar frame 103 is 0.03 mm smaller than the height of the kovar column 102.

[0081] In this embodiment, the thermal expansion coefficients of the 4J29 kovar alloy and the alumina ceramic substrate are close, ensuring the high reliability of the multi-substrate stacked packaging structure.

[0082] In this embodiment, the nickel-gold coating facilitates the welding between the kovar column 102 and the kovar frame 103 and the alumina ceramic substrate.

[0083] In this embodiment, the height of the kovar frame 103 is 0.03 mm smaller than the height of the kovar column 102 to ensure sufficient contact between the internal kovar column 102 and the alumina ceramic substrates on the upper and lower sides.

[0084] Step 3: Weld between the lower substrate 101 and the plurality of kovar posts 102 to obtain the processed lower substrate, and weld between the upper substrate 104 and the kovar frame 103 to obtain the processed upper substrate. After welding, perform atomization cleaning on all solder joints, and respectively assemble and weld the passive components 5 and the chips 6 inside the processed lower substrate and the processed upper substrate to obtain the assembled lower substrate and the assembled upper substrate.

[0085] In Step 3, the welding method is vacuum eutectic welding.

[0086] The type of solder preforms used during the welding process is all Au80Sn20 solder preforms, and the thickness of the solder preforms is 0.15 mm.

[0087] In this embodiment, the passive components 5 are passive components commonly known and used.

[0088] In this embodiment, the chips 6 are chips commonly known and used.

[0089] In this embodiment, the passive components 5 and the alumina ceramic substrate are connected by interconnecting wires 14.

[0090] In this embodiment, the chips 6 and the alumina ceramic substrate are connected by interconnecting wires 14.

[0091] In this embodiment, the interconnecting wires 14 are interconnecting wires commonly known and used.

[0092] In this embodiment, the vacuum eutectic welding method is a vacuum eutectic welding method commonly known and used.

[0093] Step 4: As Figure 6 shown, place the kovar post solder preforms 3 on the top of each kovar post 102 in the assembled upper substrate obtained in Step 3, place the kovar frame solder preforms 4 at the positions where the kovar frames 103 need to be arranged on the surface of the assembled lower substrate obtained in Step 3, and then use a special lamination tooling to align and weld between the assembled lower substrate and the assembled upper substrate. The kovar posts 102 and the kovar frames 103 are placed between the assembled lower substrate and the assembled upper substrate, and the kovar posts 102 are placed inside the kovar frames 103 to obtain the bottommost substrate unit 1.

[0094] In Step 4, the atmosphere inside the welder during welding is nitrogen.

[0095] In this embodiment, the special lamination tooling ensures the position accuracy of the kovar frames 103 and the kovar posts 102 during subsequent transfer and welding processes.

[0096] In this embodiment, the upper board positioning holes 12 and the bottom board positioning holes 11 are vertically aligned one by one, that is, the central axes of the left upper board positioning holes 12 and the left bottom board positioning holes 11 are collinear; the central axes of the right upper board positioning holes 12 and the right bottom board positioning holes 11 are collinear.

[0097] In this embodiment, the positioning pins 13 are used to achieve the positioning and assembly between the subsequent upper substrate 104 and the lower substrate 101.

[0098] In this embodiment, a thermal release adhesive is used to bond the lower substrate 101, the upper substrate 104 and the dedicated lamination tooling, which is used to ensure the stable positions of the lower substrate 101 and the upper substrate 104 in the dedicated lamination tooling during the subsequent assembly process, as well as the precise positioning between the upper substrate 104 and the lower substrate 101, to ensure circuit connectivity. After welding, the adhesiveness disappears, facilitating disassembly.

[0099] In this embodiment, the assembled lower substrate is placed at the bottom board groove 8 and bonded with a thermal release adhesive, and the assembled upper substrate is placed at the upper board groove 10 and bonded with a thermal release adhesive. The assembled lower substrate and the assembled upper substrate are further positioned by using the bottom board positioning holes 11, the upper board positioning holes 12 and the positioning pins 13.

[0100] In this embodiment, a pressing block is used to press the substrate unit 1 to ensure that the heights of multiple kovar columns 102, that is, the kovar column array, are consistent after welding, and the height of the kovar frame 103 is also consistent.

[0101] Step Five, as Figure 2 shown, the upper surface of the upper substrate in the bottommost substrate unit 1 obtained in Step Four is used as the upper surface of the lower substrate in the upper layer of substrate unit 1, and Steps One to Four are repeated to obtain multiple substrate units 1 stacked vertically in repetition.

[0102] In this embodiment, taking the double-substrate lamination packaging structure as an example, Steps One to Four are repeated twice to obtain two substrate units 1 stacked vertically in repetition.

[0103] Step Six, as Figure 2 shown, a plurality of device lead-out terminals 2 are welded to the bottom of the lower substrate 101 in the bottommost substrate unit 1 to obtain a multi-substrate lamination packaging structure.

[0104] In this embodiment, the obtained multi-substrate lamination packaging structure is a double-substrate lamination packaging structure, and the specific structure schematic diagram is as Figure 2 shown.

[0105] In this embodiment, the solder pads are wetted with a soldering flux before soldering; the atmosphere in the soldering apparatus is a nitrogen atmosphere during soldering; and after soldering, cleaning is performed by atomization cleaning.

Claims

1. A multi-substrate stacked packaging structure based on a Kovar column array, characterized in that: The invention comprises a plurality of substrate units (1) repeatedly stacked in a vertical direction, each substrate unit (1) comprising a lower substrate (101) arranged horizontally, a plurality of fellable columns (102) being evenly arranged in an array on the top of the lower substrate (101), the central axis of each fellable column (102) being arranged vertically, a fellable frame (103) being also arranged on the top of the lower substrate (101), the plurality of fellable columns (102) being arranged inside the fellable frame (103); an upper substrate (104) being also arranged on the top of the fellable columns (102), the upper substrate (104) being parallel to the lower substrate (101); In the stacked substrate units (1), the lower substrate (101) of the substrate unit (1) is the upper substrate (104) of the adjacent substrate unit (1) below, and the upper substrate (104) of the substrate unit (1) is the lower substrate (101) of the adjacent substrate unit (1) above.

2. The multi-substrate stacked packaging structure based on a Kovar pillar array as claimed in claim 1, characterized in that: A plurality of device lead terminals (2) are arranged at the bottom of the lower substrate (101) in the substrate unit (1) located at the bottom.

3. A multi-substrate stacking packaging method based on a Kovar column array, characterized in that: The method adopts the multi-substrate stacked packaging structure based on the Kovar pillar array as claimed in claim 2; The method uses a kovable column assembly tool and a stacking special tool for packaging.

4. The multi-substrate stacking packaging method based on a Kovar pillar array as claimed in claim 3, characterized in that: The kovable column assembly tool comprises a tool base plate (15) arranged horizontally, a tool base plate groove (16) is provided at the center of the upper surface of the tool base plate (15), the size of the tool base plate groove (16) is equal to the size of the lower substrate (101), and tool base plate positioning holes (18) penetrating the upper and lower ends are respectively provided on the left and right sides of the tool base plate (15); The fetchable column assembly tooling also includes a horizontally arranged tooling leaking plate (17), the tooling leaking plate (17) is located on the top of the tooling bottom plate (15), a plurality of fetchable column through holes (19) are evenly arranged in the horizontal direction at the center of the tooling leaking plate (17), each of the fetchable column through holes (19) passes through the upper and lower ends of the tooling leaking plate (17), the diameter of each of the fetchable column through holes (19) is equal to the diameter of the fetchable column (102), and tooling leaking plate positioning holes (20) passing through the upper and lower ends are respectively opened on the left and right sides of the tooling leaking plate (17), and the tooling leaking plate positioning holes (20) and the tooling bottom plate positioning holes (18) correspond one to one in the vertical direction; The same detachable column assembly locating pin (21) is arranged in each of the tooling bushing locating holes (20) and the tooling base plate locating holes (18) corresponding to the vertical bottom.

5. The multi-substrate stacking packaging method based on a Kovar pillar array as claimed in claim 4, characterized in that: The lamination-specific tooling comprises a bottom plate (7) arranged horizontally, a bottom plate groove (8) is provided at the center of the upper surface of the bottom plate (7), the size of the bottom plate groove (8) is equal to the size of the lower substrate (101), and bottom plate positioning holes (11) penetrating the upper and lower ends are provided on the left and right sides of the bottom plate (7); The stacking tooling also includes a horizontally arranged upper plate (9), the upper plate (9) being located on the top of the bottom plate (7), an upper plate groove (10) being provided at the center of the lower surface of the upper plate (9), the size of the upper plate groove (10) being equal to the size of the upper substrate (104), and upper plate positioning holes (12) penetrating the upper and lower ends being provided on the left and right sides of the upper plate (9), the upper plate positioning holes (12) and the bottom plate positioning holes (11) corresponding one to one in the vertical direction; The same positioning pin (13) is arranged in each bottom plate positioning hole (11) and the upper plate positioning hole (12) corresponding to the vertical top.

6. The multi-substrate stacking packaging method based on a Kovar pillar array as claimed in claim 5, characterized in that: The method specifically comprises the following steps: Step 1: using a tool for assembling kovable columns, placing the lower substrate (101) in the groove (16) of the tool bottom plate, and bonding it with a thermal release adhesive, and then placing kovable column welding pieces (3) at all positions on the surface of the lower substrate (101) where the kovable columns (102) are to be arranged; At the same time, the upper substrate (104) is placed in the upper plate groove (10) of the upper plate (9) in the lamination tooling, and is bonded using a thermal release adhesive, and then a clasp welding piece (4) is placed at a position on the surface of the upper substrate (104) where the clasp welding piece (103) is to be arranged; Step 2: using a tool for assembling kovable columns, placing a plurality of kovable columns (102) on the surface of the lower substrate (101) at all locations where kovable column welding pads (3) are arranged, and simultaneously using a tool for laminating, placing a kovable frame (103) on the surface of the upper substrate (104) at all locations where kovable frame welding pads (4) are arranged; Step three, welding the lower substrate (101) and the plurality of kovable columns (102) to obtain a processed lower substrate, welding the upper substrate (104) and the kovable frame (103) to obtain a processed upper substrate, atomizing and cleaning all welding points after welding, and assembling and welding the passive components (5) and chips (6) inside the processed lower substrate and the processed upper substrate respectively to obtain an assembled lower substrate and an assembled upper substrate; Step 4: placing a kovable column welding piece (3) on the top of each kovable column (102) in the assembled upper substrate obtained in step 3, placing a kovable frame welding piece (4) on the surface of the assembled lower substrate obtained in step 3 at the position where the kovable frame (103) is to be arranged, and then using a special lamination tool to align and weld the assembled lower substrate and the assembled upper substrate, placing the kovable column (102) and the kovable frame (103) between the assembled lower substrate and the assembled upper substrate, and placing the kovable column (102) on the inner side of the kovable frame (103), thereby obtaining the bottommost substrate unit (1); Step 5, using the upper surface of the upper substrate in the bottommost substrate unit (1) obtained in step 4 as the upper surface of the lower substrate in the upper substrate unit (1), repeating steps 1 to 4 to obtain a plurality of substrate units (1) repeatedly stacked in the vertical direction; Step six, welding a plurality of device lead terminals (2) to the bottom of the lower substrate (101) in the lowermost substrate unit (1) to obtain a multi-substrate stacked packaging structure.

7. The multi-substrate stacking packaging method based on a Kovar pillar array as claimed in claim 6, characterized in that: In step 1, the material of the lower substrate (101) and the material of the upper substrate (104) are ceramic substrates, and the ceramic substrates include aluminum oxide ceramic substrates, aluminum nitride ceramic substrates and silicon carbide ceramic substrates; The diameter of the welding pad corresponding to the cuttable column (102) is (1.2-1.6)×the diameter of the cuttable column (102); The width of the pad corresponding to the cuttable frame (103) is (1.2-1.6)×the wall thickness of the cuttable frame (103); The diameter of the cuttable column (102) is 0.3 mm to 0.8 mm, and the height of the cuttable column (102) is 1 mm to 3 mm; The kovable column welding piece (3) is 0.01 mm to 0.025 mm thinner than the kovable frame welding piece (4).

8. The multi-substrate stacking packaging method based on a Kovar pillar array as claimed in claim 6, characterized in that: In step 2, the material of the fellable column (102) and the material of the fellable frame (103) are both 4J29 fellable alloy; The surfaces of the fellable column (102) and the fellable frame (103) are uniformly provided with a coating, and the coating is nickel-gold; The height of the fellable frame (103) is reduced by 0.02 mm to 0.05 mm compared to the height of the fellable column (102).

9. The multi-substrate stacking packaging method based on a Kovar pillar array as claimed in claim 6, characterized in that: In step 3, the welding method is reflow welding or vacuum eutectic welding; The welding pieces used in the welding process are all Au80Sn20 welding pieces, and the thickness of the welding pieces is 0.05mm-0.2mm.

10. The multi-substrate stacking packaging method based on a Kovar pillar array according to claim 6, characterized in that: In step 4, the atmosphere in the welder during welding is nitrogen.

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