Micro-channel copper core embedded PCB packaging integrated power module and manufacturing method

Abstract

The invention discloses a micro-channel copper core embedded PCB packaging integrated power module and a manufacturing method thereof. The method comprises the following steps: manufacturing an AMB with a three-dimensional micro-channel network through a metal 3D printing and welding technology; mounting a power chip on the upper surface of the AMB through diffusion welding; placing the AMB on which the chip is mounted into the pre-processing cavity of the printed circuit board; a chip electrode is led out through a vertical interconnection structure formed by laser copper plating; a window is formed in the bottom layer of the PCB opposite to the micro-channel copper block, the bottom of the copper block is exposed, a micro-channel opening is opened, and finally copper and nickel are electroplated on the inner wall of the window to form a sealed fluid inlet and outlet. Flexible design and manufacturing of the micro-channel structure are achieved through 3D printing, efficient, short-distance and direct cooling of a chip is achieved, meanwhile, the high-density integration characteristic of a system is kept, and the heat dissipation capacity and reliability of high-power-density electronic equipment are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic packaging and heat dissipation technology, and particularly relates to a micro-channel copper core embedded PCB packaging integrated power module and a manufacturing method. BACKGROUND

[0002] The core problem of the embedded power module in the prior art is that:

[0003] 1. Heat dissipation bottleneck: the traditional scheme conducts heat to the external heat sink through the PCB layer, and the heat path is long and the thermal resistance is large.

[0004] 2. Non-uniform heat density: the "hot spot" temperature directly generated by the chip is much higher than the average temperature of the module, which limits the overall power.

[0005] 3. Contradiction between integration and reliability: increasing integration will exacerbate heat dissipation difficulties, and increasing heat dissipation structures will lead to increased volume and increased interfaces, reducing reliability.

[0006] 4. Defects of the existing liquid cooling scheme: there is an additional contact thermal resistance between the external liquid cooling plate and the module substrate, and it is difficult to accurately dissipate heat for a single chip. SUMMARY

[0007] The purpose of the present application is to provide a micro-channel copper core embedded PCB packaging integrated power module and a manufacturing method, which solves the technical problems of poor heat dissipation, contradiction between integration and reliability, and defects of the liquid cooling scheme in the prior art.

[0008] To achieve the above purpose, the present application adopts the following technical solutions.

[0009] A micro-channel copper core embedded PCB packaging integrated power module, comprising: an AMB substrate, a chip 6, a multilayer printed circuit board main body, a vertical electrical interconnection structure 5 and a fluid inlet and outlet 13.

[0010] The chip is welded in the upper surface groove 14 of the AMB substrate by diffusion welding or silver sintering, forming a micro-channel copper core composite 15.

[0011] The multilayer printed circuit board main body core board forms a fishing groove 12 inside, which is used for embedding and fixing the micro-channel copper core composite 15 in the fishing groove 12.

[0012] The vertical electrical interconnection structure 5 penetrates part of the dielectric layer of the multilayer printed circuit board main body and is electrically connected with the upper surface circuit of the AMB substrate.

[0013] The fluid inlet and outlet 13 is arranged at the bottom of the multilayer printed circuit board main body and is in fluid communication with the micro-channel in the micro-channel copper block 11.

[0014] The aforementioned micro-channel copper core embedded PCB packaging integrated power module, the AMB substrate comprises a micro-channel copper block 11, a ceramic sheet 7 and a copper foil 17.

[0015] The inner surface of the micro-channel is provided with a metal plating layer.

[0016] The micro-channel copper block 11 is combined with the ceramic sheet 7 and the copper foil 17 through active metal brazing to form the AMB substrate as a bottom copper layer.

[0017] The sidewall of the AMB substrate is filled with insulating resin 4 between the inner wall of the trough 12.

[0018] The aforementioned micro-channel copper core embedded PCB packaging integrated power module, the metal plating layer is a chemical nickel plating layer.

[0019] The aforementioned micro-channel copper core embedded PCB packaging integrated power module, the micro-channel copper block 11 is integrally formed by metal 3D printing technology.

[0020] The aforementioned micro-channel copper core embedded PCB packaging integrated power module, the fluid inlet and outlet 13 comprises a window 16 and an electroplated sealing layer 10.

[0021] The window is arranged on the bottom layer of the multilayer printed circuit board body and exposes the bottom of the micro-channel copper block 11, and the electroplated sealing layer 10 is located on the inner wall of the window 16 and the bottom surface layer of the micro-channel copper block 11.

[0022] The aforementioned micro-channel copper core embedded PCB packaging integrated power module, the electroplated sealing layer 10 is an electroplated copper layer and an electroplated nickel layer stacked in sequence.

[0023] A manufacturing method of a micro-channel copper core embedded PCB packaging integrated power module, comprising:

[0024] Step one: form a micro-channel copper block 11 with channels inside by metal 3D printing technology, and connect the micro-channel copper block 11 with a ceramic sheet 7 and a copper foil 17 on the upper surface of the ceramic sheet 7 to form an AMB substrate by active brazing process, wherein the micro-channel copper block 11 serves as a bottom copper layer of the AMB substrate, and the copper foil 17 serves as a top copper layer of the AMB substrate.

[0025] Step two: weld a chip on the upper surface of the AMB substrate to form a micro-channel copper core composite 15.

[0026] Step three: form a trough 12 on a circuit board body core plate, embed the micro-channel copper core composite 15 in the trough 12, and sequentially place PP and a copper layer 2 on the upper and lower surfaces of the PCB core plate for lamination and fixation.

[0027] Step four: generate a vertical electrical connection structure 5 in the laminated plate, the vertical electrical interconnection structure 5 penetrates part of the medium layer of the multi-layer printed circuit board body and is electrically connected with the upper surface circuit of the AMB substrate.

[0028] Step five: open a window 16 in the corresponding micro-channel copper block 11 bottom area of the multi-layer printed circuit board body, form an electroplating sealing layer 10, expose the micro-channel copper block 11 bottom and open the micro-channel port.

[0029] The laminated formed plate L3 to L4 is injected with insulating resin one 3.

[0030] The laminated formed plate surface is provided with a solder mask layer 1 for subsequent installation of the overall structure.

[0031] The laminated formed plate L2 to L5 is provided with an interlayer connection structure 9, the interlayer connection structure is hollow and is injected with insulating resin two 4.

[0032] The aforementioned micro-channel copper core embedded PCB packaging integrated power module manufacturing method performs chemical nickel plating treatment on the inner surface of the micro-channel 8 of the micro-channel copper block 11.

[0033] The aforementioned micro-channel copper core embedded PCB packaging integrated power module manufacturing method, the forming electroplating sealing layer 10 includes: sequentially performing electroplating copper and electroplating nickel treatment on the inner wall of the window 16.

[0034] The micro-channel copper core embedded PCB packaging integrated power module and the manufacturing method improve the heat dissipation performance, realize high-density system integration and high reliability.

[0035] The present application creates a shortest heat dissipation path of "chip - AMB ceramic - micro-channel cooling liquid"; the cooling liquid directly flows below the chip heat source, effectively manages the high heat flux, and the heat dissipation capacity is improved by an order of magnitude compared with the traditional scheme. The present application completely embeds the efficient liquid cooling system in the PCB, greatly saves the equipment space, realizes the real "on-board liquid cooling", and provides the possibility for the miniaturization and light weight of electronic equipment. The present application forms a rigid connection through brazing between the micro-channel copper block and the AMB, and the structure is stable; the inner wall of the micro-channel is plated with nickel, which effectively prevents corrosion of the cooling liquid; the fluid interface is metalized and sealed through electroplating copper and nickel, and the reliability is much higher than that of glue sealing. The present application can flexibly design any complex flow channel, such as serpentine, manifold type, multi-stage branch, etc., to optimize heat dissipation and flow resistance by using 3D printing to manufacture the micro-channel. The whole preparation process has good compatibility with the existing PCB process and has large-scale production potential. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A schematic diagram of the cross-section of an AMB with integrated microchannels;

[0037] Figure 2 A schematic diagram of the first compression cross-section after embedding the microchannel AMB composite;

[0038] Figure 3 A cross-sectional view showing the vertical electrical interconnection structure after it has been formed;

[0039] Figure 4 This is a schematic diagram of the cross-section before the fluid inlet and outlet are opened after the second pressing.

[0040] Figure 5 A schematic diagram of the final structural cross-section after the fluid inlet and outlet have been manufactured.

[0041] Figure 6 This is a complete cross-sectional schematic diagram of the AMB embedded PCB structure with integrated microchannels according to the present invention.

[0042] Reference numerals: 1- Solder resist layer; 2- Copper layer; 3- Insulating resin one; 4- Insulating resin two; 5- Vertical electrical interconnect structure; 6- Chip; 7- Ceramic sheet; 8- Microchannel; 9- Interlayer connection structure; 10- Electroplated sealing layer; 11- Microchannel copper block; 12- Scouring tank; 13- Fluid inlet / outlet; 14- Groove; 15- Microchannel copper core composite; 16- Window; 17- Copper foil. Detailed Implementation

[0043] The technical solution of the present invention will now be described in further detail with reference to the accompanying drawings.

[0044] Example 1: This example provides a microchannel copper core embedded PCB packaged integrated power module, including: an AMB substrate, a chip, a multilayer printed circuit board body, a vertical electrical interconnect structure, and fluid inlets and outlets.

[0045] The chip is soldered to the upper surface of the AMB substrate via diffusion bonding or silver sintering to form a microchannel copper core composite. A groove is formed inside the core board of the multilayer printed circuit board for embedding and fixing the AMB composite within the groove. The vertical electrical interconnect structure penetrates a portion of the dielectric layer of the multilayer printed circuit board and is electrically connected to the circuitry on the upper surface of the AMB substrate. The fluid inlet / outlet is located at the bottom of the multilayer printed circuit board and communicates with the microchannel fluid within the microchannel copper block.

[0046] The aforementioned microchannel copper core is embedded in a PCB package to integrate a power module, and the AMB substrate includes a microchannel copper block. A metal plating layer is provided on the inner surface of the microchannel. The microchannel copper block serves as the bottom copper layer and is bonded to a ceramic sheet and a top copper layer via active metal brazing to form the AMB substrate.

[0047] By creating the shortest heat dissipation path from chip to AMB ceramic to microchannel coolant, the coolant flows directly below the chip's heat source, effectively managing high heat flux density and improving heat dissipation capacity by an order of magnitude compared to traditional solutions.

[0048] The aforementioned microchannel copper core is embedded in a PCB package to integrate the power module, and the metal plating layer is a chemical nickel plating layer.

[0049] The microchannel copper block and AMB are brazed to form a rigid connection, resulting in a stable structure; the inner wall of the microchannel is plated with nickel to effectively prevent coolant corrosion.

[0050] The aforementioned microchannel copper core is embedded in a PCB package to integrate the power module, and the microchannel copper block is integrally formed using metal 3D printing technology.

[0051] By using 3D printing to manufacture microchannels, any complex flow path can be flexibly designed, such as serpentine, manifold, and multi-branched structures, to optimize heat dissipation and flow resistance; the entire manufacturing process is highly compatible with existing PCB processes and has the potential for large-scale production.

[0052] The aforementioned microchannel copper core embedded in a PCB packaged integrated power module includes a fluid inlet / outlet comprising a window and an electroplated sealing layer. The window is located on the bottom layer of the multilayer printed circuit board and exposes the bottom of the microchannel copper block. The electroplated sealing layer is located on the inner wall of the window and the bottom surface of the microchannel copper block.

[0053] The aforementioned microchannel copper core is embedded in a PCB package to integrate the power module, and the electroplated sealing layer consists of an electroplated copper layer and an electroplated nickel layer stacked sequentially.

[0054] By fully integrating the highly efficient liquid cooling system inside the PCB, significant space is saved, achieving true "onboard liquid cooling" and enabling miniaturization and weight reduction of electronic devices. The fluid interface is metallized and sealed using electroplated copper and nickel, offering far greater reliability than adhesive seals.

[0055] Example 2: Based on Example 1, this example provides a method for fabricating a microchannel copper core embedded in a PCB packaged integrated power module, including:

[0056] Step 1: Preparation of microchannel copper core composite, including:

[0057] a. Using metal 3D printing technology to manufacture copper blocks with a complex network of microchannels inside.

[0058] b. The microchannel copper block is bonded to a ceramic sheet and a copper foil to form an AMB structure using an active metal brazing process, such that the microchannel copper block serves as the bottom copper layer of the AMB, the ceramic sheet serves as the insulating layer, and the top copper foil serves as the circuit carrier layer.

[0059] c. The chip is soldered onto the top copper layer of the AMB using a sintering process to form a microchannel copper core composite.

[0060] Step 2: Embedding the composite and the first lamination, including:

[0061] a. Provide an L3 / L4 layer core board and machine grooves on it that match the shape of the microchannel copper core composite.

[0062] b. Embed the microchannel copper core composite into the retrieval slot.

[0063] c. Stack the prepreg and copper foil sequentially above the L3 layer and below the L4 layer to perform the first multilayer lamination, and initially fix the composite in the PCB body.

[0064] Step 3: Establish electrical interconnections, including:

[0065] a. Micro-blind holes are formed at locations requiring electrical connections by laser drilling from the L3 and L4 layers.

[0066] b. Solid copper pillars are formed through chemical copper plating and electroplating to bring out the chip electrodes.

[0067] Step 4: Second lamination and construction of the underlying structure, including:

[0068] a. Using the semi-finished product from step 3 as the inner layer, continue to stack prepreg and copper foil (L1 / L2, L5 / L6) on both sides (i.e. above L3 layer and below L4 layer) to perform a second multi-layer lamination, forming a complete 6-layer board structure.

[0069] b. Perform standard PCB through-hole and circuit pattern fabrication.

[0070] Step 5: Establish fluid interfaces and perform surface treatment, including:

[0071] a. From the bottom layer of the PCB (L6 layer side), align the microchannel copper block area, perform windowing and laser ablation to create a window that runs through the L5 and L6 layers, fully exposing the bottom of the microchannel copper block.

[0072] b. Perform a secondary window opening at the bottom of the exposed microchannel copper block to expose the microchannel.

[0073] c. Electroless nickel plating is performed on the inner surface of the microchannel to form an anti-corrosion layer, and copper and nickel plating are performed on the inner wall of the entire window to achieve a sealed, corrosion-resistant, and complete fluid inlet and outlet.

[0074] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. These terms are used only for the convenience of describing this application and for simplifying the description, and are not intended to indicate or imply the device or element referred to.

Claims

1. A microchannel copper core embedded in a PCB packaged integrated power module, characterized in that, include: AMB substrate, chip (6), multilayer printed circuit board body, vertical electrical interconnect structure (5) and fluid inlet / outlet (13); The chip (6) is soldered to the groove (14) on the upper surface of the AMB substrate by diffusion soldering or silver sintering to form a microchannel copper core composite (15); a groove (12) is formed inside the core board of the multilayer printed circuit board for embedding and fixing the microchannel copper core composite (15) in the groove (12); the vertical electrical interconnect structure (5) penetrates part of the dielectric layer of the multilayer printed circuit board and is electrically connected to the circuit on the upper surface of the AMB substrate; the fluid inlet and outlet (13) is set at the bottom of the multilayer printed circuit board and is in fluid communication with the microchannel (8) in the microchannel copper core composite (15).

2. The microchannel copper core embedded PCB packaged integrated power module according to claim 1, characterized in that, The AMB substrate includes a microchannel copper block (11), a ceramic sheet (7), and a copper foil (17); the inner surface of the microchannel (8) is provided with a metal plating layer; the microchannel copper block (11), the ceramic sheet (7), and the copper foil (17) are bonded together by active metal brazing.

3. The microchannel copper core embedded PCB packaged integrated power module according to claim 1, characterized in that, The space between the sidewall of the AMB substrate and the inner wall of the trough (12) is filled with insulating resin 2 (4).

4. The microchannel copper core embedded PCB packaged integrated power module according to claim 2, characterized in that, The metal plating is a chemical nickel plating layer.

5. The microchannel copper core embedded PCB packaged integrated power module according to claim 2, characterized in that, The microchannel copper block (11) is integrally formed using metal 3D printing technology.

6. The microchannel copper core embedded PCB packaged integrated power module according to claim 1, characterized in that, The fluid inlet / outlet (13) includes: a window (16) and an electroplated sealing layer (10); the window (16) is located on the bottom layer of the multilayer printed circuit board body and exposes the bottom of the microchannel copper block (11); the electroplated sealing layer (10) is located on the inner wall of the window (16) and the bottom surface of the microchannel copper block (11).

7. The microchannel copper core embedded PCB packaged integrated power module according to claim 6, characterized in that, The electroplated sealing layer (10) is composed of an electroplated copper layer and an electroplated nickel layer stacked sequentially.

8. A method for manufacturing a microchannel copper core embedded PCB packaged integrated power module as described in any one of claims 1-7, comprising: Step 1: A microchannel copper block (11) with microchannels (8) inside is formed by metal 3D printing technology. The microchannel copper block (11) is connected to the ceramic sheet (7) and its upper surface copper foil (17) by active brazing process to form an AMB substrate. The microchannel copper block (11) is used as the bottom copper layer of the AMB substrate, and the copper foil (17) is used as the top copper layer of the AMB substrate. Step 2: The chip is soldered to the upper surface of the AMB substrate to form a microchannel copper core composite (15). Step 3: Form a groove (12) inside the core board of the PCB, embed the microchannel copper core composite (15) into the groove (12), and place PP and copper layer (2) on the top and bottom of the PCB Core board in sequence for lamination and fixation; Step 4: A vertical electrical interconnection structure (5) is generated in the laminated board. The vertical electrical interconnection structure (5) penetrates part of the dielectric layer of the multilayer printed circuit board body and is electrically connected to the upper surface circuit of the AMB substrate. Step 5: Open a window (16) in the bottom area of ​​the corresponding microchannel copper block on the multilayer printed circuit board body to form an electroplated sealing layer (10), expose the bottom of the microchannel copper block (11) and open the microchannel opening.

9. The method for fabricating a microchannel copper core embedded in a PCB packaged integrated power module according to claim 8, characterized in that, The inner surface of the microchannel of the copper block is subjected to chemical nickel plating.

10. The method for fabricating a microchannel copper core embedded in a PCB packaged integrated power module according to claim 9, characterized in that, The formation of the electroplated sealing layer (10) includes: sequentially electroplating copper and electroplating nickel on the inner wall of the window (16).

Images