A three-dimensional integrated rectifier array and its manufacturing method

Abstract

The present invention discloses a three-dimensional integrated rectifier array and a manufacturing method thereof, comprising: an AMB-ceramic substrate, a metal ring frame is fixedly provided along the periphery of the upper end surface thereof, the metal ring frame and the AMB-ceramic substrate form a cavity, a through hole is provided on the AMB-ceramic substrate located in the cavity, and a copper column is filled in the through hole; a first pad, comprising an anode pad Pn and a cathode pad Nn, the first pad is welded on the upper surface and the lower surface of the copper column, and the anode pad Pn and the cathode pad Nn are arranged at intervals, and the first pad welded on the same copper column is of the same type; a diode chip, which is located in the cavity and arranged on the upper end surface of the anode pad Pn, the diode chip is interconnected with the adjacent cathode pad Nn; and a metal cover plate for sealing the cavity. The three-dimensional integrated rectifier array in the present invention has small size, light weight, high reliability and good air tightness.

Description

Technical Field

[0001] The invention belongs to the field of electronic devices, and in particular relates to a three-dimensional integrated rectifier array and a manufacturing method thereof. Background Art

[0002] High-density ultra-small rectifier arrays have the characteristics of high chip integration, small size, and flexible application. They can save space and simplify the circuit layout area, which is in line with the development trend of miniaturization and lightweight of aerospace devices. They have gradually become the core components used in current military communication satellites, navigation systems, and microwave data transmission systems for manned space projects. The centralized control of multiple high-power density signals in satellite systems must be achieved by using high-power density multi-channel integrated switches. In addition, the functions of half-wave rectification, full-wave rectification, bridge rectification, etc., which are widely used in high-voltage output power supplies of aerospace systems, currently require discrete rectifier diodes of different structures to be realized through series and parallel connection. The wiring is complicated and not conducive to miniaturization. In addition, according to different rectification requirements, the rectifier circuit needs to be designed into different structures, and the compatibility and reconfigurability are poor.

[0003] Domestic aerospace satellite-borne rectifier diode devices are still mainly single-chip single-tube, and no manufacturer has launched high-density miniaturized multi-chip three-dimensional integrated array products, and the process manufacturing technology still faces many difficulties. This type of product has become a major technical bottleneck restricting the development of my country's satellite data transmission system. Summary of the invention

[0004] In view of this, it is necessary for the present invention to provide a three-dimensional integrated rectifier array and a manufacturing method thereof. The three-dimensional integrated rectifier array takes the AMB-ceramic substrate as the core, welds the AMB-ceramic substrate and the metal ring frame to form a cavity, forms an independent rectifier channel in the cavity, and arranges a solder pad at the bottom, so that the rectifier array has a small size, light weight, high power, reconfigurable topology, and excellent airtightness, which solves the technical problems of the existing rectifier array with poor compatibility and reconfigurability and the inability to be miniaturized with high density.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A three-dimensional integrated rectifier array, comprising:

[0007] The AMB-ceramic substrate has a metal ring frame fixedly arranged around its upper end surface, the metal ring frame and the AMB-ceramic substrate form a cavity, the AMB-ceramic substrate in the cavity is provided with a through hole, and the through hole is filled with a copper column;

[0008] A first pad, comprising an anode pad Pn and a cathode pad Nn, wherein the first pads are welded on the upper surface and the lower surface of the copper column, and the anode pad Pn and the cathode pad Nn are arranged at intervals, and the first pads welded on the same copper column are of the same type;

[0009] A diode chip, which is located in the cavity and disposed on the upper end surface of the anode pad Pn, and the diode chip is interconnected with the adjacent cathode pad Nn through aluminum wire bonding;

[0010] A metal cover plate is arranged at the upper end of the metal ring frame to seal the cavity.

[0011] Furthermore, the AMB-ceramic substrate is an AMB-AlN ceramic substrate.

[0012] Furthermore, the metal ring frame is a varable metal ring frame.

[0013] Furthermore, it also includes:

[0014] The second pad, which is a Pad pad, is welded on the bottom of the AMB-ceramic substrate and has no connection with the first pad.

[0015] Preferably, the second pad is located at the bottom center of the AMB-ceramic substrate.

[0016] Furthermore, the through holes are arranged in an array around the AMB-ceramic substrate, and the anode pads Pn and the cathode pads Nn are arranged at intervals.

[0017] Furthermore, the diode chip is a stacked chip, which is composed of two layers of diode bare chips stacked in series, and the diode bare chip located on the upper layer of the stacked chip is interconnected with the adjacent cathode pad Nn through aluminum wire bonding.

[0018] The present invention also provides a method for manufacturing the above-mentioned three-dimensional integrated rectifier array, comprising the following steps:

[0019] Clean the ceramic substrate and anneal and clean the copper sheet;

[0020] After punching a through hole on the cleaned ceramic substrate, the ceramic substrate is cleaned again and a copper column is filled in the through hole. Then, active solder is printed on the surface of the ceramic substrate, and the cleaned copper sheet is welded to the ceramic substrate through an active brazing process.

[0021] After removing impurities or waste from the ceramic substrate and completing circuit fabrication, laser scribing is performed to obtain an AMB-ceramic substrate;

[0022] The AMB-ceramic substrate filled with copper pillars is heated to soften the copper material, and an external force is applied to cause the copper-clad substrate to be concave and deformed to contact the copper pillars;

[0023] Soldering the first pads on the upper and lower surfaces of the copper column, and soldering the second pads on the bottom of the AMB-ceramic substrate;

[0024] A diode chip is fabricated on an anode pad Pn located on the upper end surface of an AMB-ceramic substrate, and the diode chip is interconnected with an adjacent cathode pad Nn by aluminum wire bonding;

[0025] After the metal ring frame is welded to the upper end surface of the AMB-ceramic substrate, the metal ring frame is sealed with a metal cover plate by parallel sealing welding to achieve airtight packaging.

[0026] Furthermore, the active solder is composed of Ti-Ag-Cu and an organic carrier.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention adopts an AMB-ceramic metal integrated housing, and the internal diode chips are interconnected by chip stacking and bonding. The entire rectifier array package size is small, which can achieve miniaturization, lightness, airtightness and high reliability of the rectifier array.

[0029] 2. The present invention adopts an SMD structure, which can achieve an expansion of the current flow capacity up to 20A, and can conduct the heat dissipation of each channel vertically downward through the copper column pad to ensure the heat dissipation performance of the device.

[0030] 3. The topology of the present invention is reconfigurable and can be realized through external wiring according to the use needs, with flexible application and good compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic cross-sectional structure diagram of a three-dimensional integrated rectifier array in a preferred embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the internal structure of the cavity of a three-dimensional integrated rectifier array in a preferred embodiment of the present invention;

[0033] Figure 3 A schematic diagram of the bottom pad layout of a three-dimensional integrated rectifier array in a preferred embodiment of the present invention;

[0034] Figure 4 It is a circuit structure diagram of a three-dimensional integrated rectifier array in a preferred embodiment of the present invention.

[0035] In the figure: 1-AMB-AlN ceramic substrate, 2-copper column, 3-metal ring frame, 4-metal cover plate, 5-first pad, 51-anode pad Pn, 52-cathode pad Nn, 6-diode chip, 7-aluminum wire, 8-second pad. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0038] like Figure 1 As shown in, a three-dimensional integrated rectifier array includes an AMB-AlN ceramic substrate 1. It can be understood that the AMB-AlN ceramic substrate 1 here is an optimal way in the present invention. The ceramic substrate here can select other ceramic substrates in the field. Since the thermal conductivity of the AlN ceramic substrate is high, the AlN ceramic substrate is preferably used in this embodiment. Specifically, the AMB-AlN ceramic substrate 1 here is an SMD structure formed by the AMB process. Specifically, the ceramic substrate is coated with active solder and then active brazing is performed to join the ceramic and the metal. It is applied in the field of structural packaging for the first time. The AMB-AlN ceramic substrate 1 uses a small amount of active elements contained in the brazing material to react with the ceramic to generate a reaction layer that can be wetted by the liquid brazing material to achieve the bonding of the ceramic and the metal and ensure the air tightness of the package.

[0039] Please combine Figure 2 and Figure 1See, further, a metal ring frame 3 is fixedly provided on the upper end surface of the AMB-AlN ceramic substrate 1 along its periphery. The material of the metal ring frame 3 here can be a material commonly used in the field of metal shell packaging. In this embodiment, the metal ring frame 3 is a Kovar metal ring frame. In this embodiment, it is welded to the AMB-AlN ceramic substrate 1 by silver-copper welding. Thus, the AMB-AlN ceramic substrate 1 and the metal ring frame 3 form a cavity, and the circuit structure of the rectifier array in this embodiment is wired in the cavity. Specifically, a through hole is opened on the AMB-AlN ceramic substrate 1 located in the cavity, and a copper column 2 is filled in the through hole. The first pad 5 is welded on the upper and lower surfaces of the copper column 2. Preferably, the close connection of the first pad 5 on the upper and lower surfaces is ensured, so as to achieve the flow capacity of large current, and the heat dissipation of each channel can be vertically conducted downward through the copper column 2 to achieve efficient heat dissipation. The first pads 5 here include anode pads Pn 51 and cathode pads Nn 52. The types of the first pads 5 welded on the upper and lower surfaces of the same copper column 2 are the same, that is, the upper and lower surfaces of the same copper column 2 are either welded with anode pads Pn 51 or cathode pads Nn 52. The anode pads Pn 51 and the cathode pads Nn 52 are arranged at intervals. The safe distance between the first pads 5 is not described in detail here. In this embodiment, the spacing between the first pads 5 is selected to be 0.5 mm. Preferably, in this embodiment, the through holes are arranged in an array around the four sides of the AMB-AlN ceramic substrate 1, so that the first pads 5 are also arranged in an array, and the anode pads Pn 51 and the cathode pads Nn 52 are arranged at intervals.

[0040] Furthermore, a diode chip 6 is connected to the upper end surface of the anode pad Pn 51 located in the cavity, as shown in FIG. Figure 1 As shown in , the diode chip 6 is interconnected with the adjacent cathode pad Nn by aluminum wire bonding. Further, in this embodiment, the diode chip 6 is a stacked chip, which is formed by stacking two layers of diode bare chips in series. Figure 2 As shown in the figure, the diode bare chip on the top layer is bonded to the adjacent cathode pad Nn 52 through the aluminum wire 7 to achieve interconnection. It can be understood that the number of aluminum wires 7 here can be 2 or more than 3, which can be adjusted according to needs and is not specifically limited here.

[0041] The circuit connection of the rectifier array in this embodiment is as follows: Figure 2 As shown in FIG. 1 , eight diode chips 6 form eight independent rectification channels, each rectification channel is composed of an anode pad Pn 51, a cathode pad Nn 52 adjacent thereto, and a diode chip 6 disposed on the anode pad Pn 51, which are connected in series end to end. The arrangement of the first pad 5 at the bottom of the AMB-AlN ceramic substrate 1 is as follows: Figure 3As shown in FIG, a second pad 8 is welded in the middle. The second pad 8 is a Pad pad, which has no electrical connection with the surrounding first pads 5 and is mainly used for heat dissipation and ensuring welding reliability. The specific position can be adjusted as needed. In this embodiment, it is preferably welded at the center of the bottom. Specifically, the circuit structure of the 8 rectifier channels is as follows: Figure 4 As shown in , it can realize topological reconstruction by changing the series-parallel relationship of each rectification channel externally, so as to meet the functions of half-wave rectification, full-wave rectification, bridge rectification, high-voltage rectification and the like.

[0042] The three-dimensional integrated rectifier array in this embodiment has a small size of 11.5mm×11.5mm×3.2mm. The size of P1, P3, P5 and P7 in the anode pad Pn51 is 2.7mm×2.7mm, and the size of the remaining pads N1, P2, N2, N3, P4, N4, N5, P6, N6, N7, P8 and N8 is 1.3mm×2.7mm. The size of the second pad 8 is designed to be 4.9mm×4.9mm. Figure 2 and Figure 3 As shown in the figure, the anode pad Pn 51 and the cathode pad Nn 52 are arranged at intervals, and the anode and cathode pads of each independent rectification channel are arranged adjacent to each other. The diode chip 6 is evenly distributed on the AMB-AlN ceramic substrate 1 and is directly soldered above the copper column 2 pad to ensure good heat dissipation and square resistance characteristics.

[0043] Further solutions, such as Figure 1 As shown in FIG, a metal cover plate 4 is sealed on the metal ring frame 3 to seal the cavity.

[0044] This embodiment also discloses a method for manufacturing a three-dimensional integrated rectifier array, which includes the following steps:

[0045] The AlN ceramic substrate is cleaned and the copper sheet is annealed and cleaned; the cleaning, annealing and other treatments here are all commonly used in the art, so they will not be described in detail;

[0046] After punching a through hole on the cleaned AlN ceramic substrate, the substrate is cleaned again and a copper column 2 is filled in the through hole. Then, active solder is printed on the surface of the AlN ceramic substrate, and the cleaned copper sheet is welded to the AlN ceramic substrate through an active brazing process.

[0047] Removing impurities or waste on the AlN ceramic substrate. In this embodiment, the impurities and waste are mainly removed by copper etching solution and solder etching solution. After the circuit is manufactured, the AMB-AlN ceramic substrate 1 is obtained by laser scribing.

[0048] The AMB-AlN ceramic substrate 1 is heated to soften the copper material, and an external force is applied to make the copper-clad substrate dent and deform to contact the copper pillar 2. Specifically, the external force can be applied through a crimping process to make the copper-clad substrate dent and deform to contact the copper pillar 2. This step is mainly to ensure that the first pads 5 on the upper and lower surfaces of the copper pillar 2 are tightly connected.

[0049] A first pad 5 is welded on the upper and lower surfaces of the copper column 2, and a second pad 8 is welded on the bottom of the AMB-AlN ceramic substrate 1;

[0050] A diode chip 6 is manufactured on the anode pad Pn 51 located on the upper end surface of the AMB-AlN ceramic substrate 1, and the diode chip is bonded and interconnected with the adjacent cathode pad Nn 52 through an aluminum wire 7;

[0051] After welding the AMB-AlN ceramic substrate 1 to the metal ring frame 3, the metal cover plate 4 is used to seal the metal ring frame by parallel sealing to achieve airtight packaging. The welding methods here are conventional operations in the art, so they will not be described in detail.

[0052] Furthermore, the active solder is composed of Ti-Ag-Cu and an organic carrier.

[0053] The rectifier array in this embodiment has small size, light weight, reconfigurable topology, high reliability, excellent air tightness, and a leakage rate of less than 1×10 -8 atm.com 3 sec -1 , which can meet the application requirements of aerospace and satellite.

[0054] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for manufacturing a three-dimensional integrated rectifier array, characterized in that: The following steps are involved: Clean the ceramic substrate and anneal and clean the copper sheet; After punching a through hole on the cleaned ceramic substrate, the ceramic substrate is cleaned again and a copper column is filled in the through hole. Then, an active solder is printed on the surface of the ceramic substrate, and the cleaned copper sheet is welded to the ceramic substrate through an active brazing process, wherein the active solder is composed of Ti-Ag-Cu and an organic carrier; After removing impurities or waste from the ceramic substrate and completing circuit fabrication, laser scribing is performed to obtain an AMB-ceramic substrate; The AMB-ceramic substrate filled with copper pillars is heated to soften the copper material, and external force is applied to cause the copper-clad substrate to be concave and deformed to contact the copper pillars; Soldering the first pads on the upper and lower surfaces of the copper column, and soldering the second pads on the bottom of the AMB-ceramic substrate; A diode chip is fabricated on an anode pad Pn located on the upper end surface of an AMB-ceramic substrate, and the diode chip is interconnected with an adjacent cathode pad Nn by aluminum wire bonding; After the metal ring frame is welded to the upper end surface of the AMB-ceramic substrate, the metal ring frame is sealed with a metal cover plate by parallel sealing welding to achieve airtight packaging.

2. The method for manufacturing a three-dimensional integrated rectifier array according to claim 1, characterized in that: include: The AMB-ceramic substrate has a metal ring frame fixedly arranged around its upper end surface, the metal ring frame and the AMB-ceramic substrate form a cavity, the AMB-ceramic substrate in the cavity is provided with a through hole, and the through hole is filled with a copper column; A first pad, comprising an anode pad Pn and a cathode pad Nn, wherein the first pad is welded on the upper surface and the lower surface of the copper column, and the anode pad Pn and the cathode pad Nn are arranged at intervals, and the first pad welded on the same copper column is of the same type; and the surface area of ​​the first pad is greater than the upper surface area or the lower surface area of ​​the copper column; A diode chip, which is located in the cavity and disposed on the upper end surface of the anode pad Pn, and the diode chip is interconnected with the adjacent cathode pad Nn through aluminum wire bonding; A metal cover plate, which is arranged at the upper end of the metal ring frame and covers the cavity; And a second pad, which is a Pad pad, is welded on the bottom of the AMB-ceramic substrate and has no connection with the first pad.

3. The method for manufacturing a three-dimensional integrated rectifier array according to claim 1, characterized in that: The AMB-ceramic substrate is an AMB-AlN ceramic substrate.

4. The method for manufacturing a three-dimensional integrated rectifier array according to claim 1, characterized in that: The metal ring frame is a kovar metal ring frame.

5. The method for manufacturing a three-dimensional integrated rectifier array according to claim 1, characterized in that: The second pad is located at the bottom center of the AMB-ceramic substrate.

6. The method for manufacturing a three-dimensional integrated rectifier array according to claim 1, characterized in that: The through holes are arranged in an array around the AMB-ceramic substrate, and the anode pads Pn and the cathode pads Nn are arranged at intervals.

7. The method for manufacturing a three-dimensional integrated rectifier array according to claim 1, characterized in that: The diode chip is a stacked chip, which is composed of two layers of diode bare chips stacked in series, and the diode bare chip located on the upper layer of the stacked chip is interconnected with the adjacent cathode pad Nn through aluminum wire bonding.

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