High current density vertical power supply module and packaging process thereof

Abstract

The application discloses a high-current-density vertical power supply and distribution module and a packaging process thereof, and belongs to the technical field of microelectronic packaging. The module and the packaging process solve the problems of large size, low current density, high buried chip packaging thermal resistance, difficult heat dissipation and excessively high junction temperature of the prior art. In the module, a bottom electrode, a packaging substrate, a power device and a top electrode are stacked. Integrated circuit chips and passive devices are embedded in the packaging substrate and stacked in the vertical direction. The packaging process comprises embedding the integrated circuit chips in a first core plate, embedding the passive devices in a second core plate, and pressing to form the packaging substrate; drilling, hole wall metallization and hole plugging are performed on the packaging substrate to obtain a whole to be packaged; and the whole to be packaged is subjected to pouring, grinding and surface metallization. The module and the packaging process can effectively improve the current density.

Description

Technical Field

[0001] This invention belongs to the field of microelectronic packaging technology, and particularly relates to a high current density vertical power supply and distribution module and its packaging process. Background Technology

[0002] Driven by the demands for high computing power density, high energy efficiency, and functional integration, the power supply and distribution methods for high-performance computing, millimeter-wave, and other application systems need to shift from traditional horizontal structures to vertical structures. The power consumption density of the load chips requires the current density of the vertical power supply and distribution module to be higher than 1A / mm². 2 .

[0003] However, the power supply and distribution modules in traditional horizontal power supply and distribution structures are large in size and have low current density (≤0.3A / mm²). 2 This design cannot meet the structural requirements of a vertical power supply and distribution system, which stipulate that the module area should not exceed the load chip area and that the module ports and load chip pins should be vertically interconnected. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a high current density vertical power supply and distribution module and its packaging process, which solves the problems of large size, low current density, high thermal resistance of embedded chip packaging, difficult heat dissipation, and excessively high junction temperature of power supply and distribution modules in existing horizontal power supply and distribution structures.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] This invention provides a high current density vertical power supply and distribution module, including a packaging substrate, power devices, side electrodes, bottom electrodes, top electrodes, integrated circuit chips, and passive devices; the bottom electrodes, packaging substrate, power devices, and top electrodes are stacked sequentially from bottom to top; the side electrodes are located on the side of the packaging substrate, and the top electrodes are connected to the packaging substrate through the side electrodes; the integrated circuit chips and passive devices are embedded inside the packaging substrate, and the two are stacked in the vertical direction.

[0007] Furthermore, the aforementioned high current density vertical power supply and distribution module also includes a heat sink located on the side of the power device.

[0008] Furthermore, the heat sink includes a heat sink substrate and multiple heat sink pillars. The side of the heat sink substrate facing away from the power device is provided with a mesh groove. The multiple heat sink pillars are respectively inserted into the mesh groove and slidably connected to the mesh groove. The sidewall of the mesh groove is provided with groove wall protrusions. The end of the heat sink pillar inserted into the mesh groove is provided with pillar wall protrusions. The pillar wall protrusions are located between the bottom of the mesh groove and the groove wall protrusions.

[0009] Furthermore, the heat sink is directly connected to the power device through an insulating and thermally conductive layer.

[0010] Furthermore, the material of the insulating and thermally conductive layer is a thermally conductive resin.

[0011] Furthermore, the side electrodes, top electrodes, and / or bottom electrodes serve as signal ports and / or power ports.

[0012] Furthermore, the side electrodes are directly connected to the metal layer inside the packaging substrate.

[0013] Furthermore, the maximum power of integrated circuit chips does not exceed 3W, and the maximum power consumption of power devices is above 10W.

[0014] Furthermore, the aforementioned high current density vertical power supply and distribution module also includes an inductor located between the top electrode and the power device.

[0015] Furthermore, the projected area of ​​the inductor on the surface of the packaging substrate does not exceed the area of ​​the packaging substrate surface, and the height of the bottom of the inductor from the surface of the packaging substrate is greater than or equal to the mounting height of the power device.

[0016] The present invention also provides a packaging process for a high current density vertical power supply and distribution module, used for packaging the aforementioned high current density vertical power supply and distribution module, the packaging process comprising the following steps:

[0017] A first core board and a second core board are provided, wherein an integrated circuit chip is embedded in the first core board and a passive device is embedded in the second core board;

[0018] The first core board and the second core board are pressed together to form a packaging substrate;

[0019] Holes are drilled on the lower surface of the packaging substrate, and the hole walls are metallized. Solder resist is used to plug the holes, and a bottom electrode is formed on the lower surface of the packaging substrate to obtain the whole package.

[0020] The entire package to be packaged is encapsulated to obtain the packaged product.

[0021] Grind the entire package until the sidewalls of the package substrate are exposed;

[0022] The surface of the polished package is metallized to form side electrodes and top electrodes, resulting in a high current density vertical power supply and distribution module.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] A) The high current density vertical power supply and distribution module provided by this invention has a layered stacked structure. Accordingly, in the overall vertical direction from bottom to top, the bottom electrode, the packaging substrate, the power device, and the top electrode are stacked sequentially. Inside the packaging substrate, passive devices and integrated circuit chips are stacked, thereby effectively reducing the area of ​​the power supply and distribution module. The current density of existing power supply and distribution module products is typically 0.3A / mm². 2 In this context, inductors typically occupy 1 / 4 to 1 / 2 of the total area. By employing a layered stacking structure, the total area of ​​the power supply and distribution module can be reduced to the area of ​​the inductors, thereby increasing the current density by 2 to 4 times compared to existing modules, i.e., 0.6 to 1.2 A / mm². 2 Through testing, the high current density vertical power supply and distribution module of this embodiment can actually increase the current density to 1A / mm². 2 The above measures enable the system to meet the structural requirements of vertical power supply and distribution systems, where the module area does not exceed the load chip area and the module ports are vertically interconnected with the load chip pins.

[0025] B) The high current density vertical power supply and distribution module provided by the present invention has a packaging substrate as the carrier of the power conversion circuit inside the power supply and distribution module; the side electrodes are used to realize the interconnection between the metal layers inside the packaging substrate and to conduct input and output signals; the bottom electrode is the interface component between the internal signals of the power supply and distribution module and the external circuit; and the integrated circuit chip is the control or drive chip of the power device.

[0026] C) The high current density vertical power supply and distribution module provided by this invention has different heating positions and temperatures on its sidewalls for high current density vertical power supply and distribution modules with different structures. In practical applications, before packaging the high current density vertical power supply and distribution module, the heating positions and temperatures on the sidewalls of the power devices can be tested. Based on the different heating positions and temperatures, the heat sinks can be concentrated at the positions with higher heating temperatures by sliding heat sinks. For positions with lower heating temperatures, the number of heat sinks can be appropriately reduced.

[0027] D) In ​​the high current density vertical power supply and distribution module provided by this invention, for the portion of the mesh groove without heat dissipation pillars, the groove wall protrusions can serve as heat dissipation fins, thereby more effectively improving the overall heat dissipation performance of the heat dissipation component. Similarly, the pillar wall protrusions on the heat dissipation pillars can also serve as heat dissipation fins.

[0028] 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. Attached Figure Description

[0029] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0030] Figure 1 This is a schematic diagram of the high current density vertical power supply and distribution module provided in Embodiment 1 of the present invention;

[0031] Figure 2 This is a structural block diagram of the high current density vertical power supply and distribution module provided in Embodiment 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the first core board and the second core board obtained in step 1 of the packaging process of the high current density vertical power supply and distribution module provided in Embodiment 2 of the present invention.

[0033] Figure 4 This is a schematic diagram of the packaging substrate structure obtained in step 2 of the packaging process of the high current density vertical power supply and distribution module provided in Embodiment 2 of the present invention.

[0034] Figure 5 This is a schematic diagram of the bottom electrode and packaging substrate structure obtained in step 3 of the packaging process of the high current density vertical power supply and distribution module provided in Embodiment 2 of the present invention.

[0035] Figure 6 This is a schematic diagram of the structure with power devices and inductors obtained in step 4 of the packaging process of the high current density vertical power supply and distribution module provided in Embodiment 2 of the present invention.

[0036] Figure label:

[0037] 1-Packaging substrate; 2-Power device; 3-Side electrode; 4-Heat sink; 5-Bottom electrode; 6-Integrated circuit chip; 7-Passive device; 8-Surface mount electrode; 9-Top electrode; 10-Inductor; 11-Lead bracket; 12-First core board; 13-Second core board. Detailed Implementation

[0038] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0039] Example 1

[0040] This embodiment provides a high current density vertical power supply and distribution module. See [link / reference] Figures 1 to 2The package includes a packaging substrate 1, a power device 2 (e.g., Si MOSFET, GaN HEMTs, SiC MOSFET, SiC JFET, IGBT, etc.), a side electrode 3, a bottom electrode 5, a top electrode 9, an integrated circuit chip 6, and a passive device 7 (e.g., a resistor and / or a capacitor). The bottom electrode 5, the packaging substrate 1, the power device 2, and the top electrode 9 are stacked sequentially from bottom to top. The side electrode 3 is located on the side of the packaging substrate 1. The top electrode 9 is connected to the packaging substrate 1 through the side electrode 3. The integrated circuit chip 6 and the passive device 7 are embedded inside the packaging substrate 1 and are stacked in the vertical direction.

[0041] Compared with existing technologies, the high current density vertical power supply and distribution module provided in this embodiment has a layered stacked structure. Accordingly, in the overall vertical direction from bottom to top, the bottom electrode 5, the packaging substrate 1, the power device 2, and the top electrode 9 are stacked sequentially. Inside the packaging substrate 1, the passive device 7 and the integrated circuit chip 6 are stacked, thereby effectively reducing the area of ​​the power supply and distribution module. The current density of existing power supply and distribution module products is typically 0.3A / mm². 2 In the following, the inductor 10 typically occupies 1 / 4 to 1 / 2 of the total area. By adopting a layered stacking structure, the total area of ​​the power supply and distribution module can be reduced to the area of ​​the inductor 10, and the corresponding current density can be increased to 2 to 4 times that of existing modules, i.e., 0.6 to 1.2 A / mm². 2 Through testing, the high current density vertical power supply and distribution module of this embodiment can actually increase the current density to 1A / mm². 2 The above measures enable the system to meet the structural requirements of vertical power supply and distribution systems, where the module area does not exceed the load chip area and the module ports are vertically interconnected with the load chip pins.

[0042] It should be noted that the high current density vertical power supply and distribution module of this embodiment can be used in electronic systems such as high-performance computing systems, T / R component systems, and optical sensing systems where the chip layout has a clustered feature and the power supply module cannot be placed horizontally.

[0043] Specifically, the functions of each of the above components are as follows:

[0044] The packaging substrate 1 serves as the carrier for the power conversion circuit within the power distribution module; the side electrode 3 is used to realize the interconnection between the metal layers inside the packaging substrate 1 and to conduct input and output signals; the bottom electrode 5 is the interface component between the internal signals of the power distribution module and the external circuit; the integrated circuit chip 6 is the control or drive chip for the power device 2.

[0045] In the prior art, the use of embedded substrate technology can reduce the size of traditional power supply and distribution modules. However, the thermal resistance of embedded chip packages is usually higher than 4K / W. When the output current is higher than 20A, the embedded chip is prone to failure to work properly due to heat dissipation difficulties and excessive junction temperature. In order to improve the heat dissipation performance of the above-mentioned high current density vertical power supply and distribution module, the above-mentioned high current density vertical power supply and distribution module also includes a heat sink 4 disposed on the side of the power device 2. The heat sink 4 is used as the external heat dissipation interface of the power device 2. The heat dissipation of the power device 2 can be conducted to the outside of the high current density vertical power supply and distribution module through the setting of the heat sink 4, thereby realizing the heat dissipation of the power device 2.

[0046] Specifically, the structure of heat sink 4 includes a heat sink substrate and multiple heat sink pillars. The side of the heat sink substrate facing away from the power device 2 has a mesh groove. Multiple heat sink pillars are inserted into the mesh groove and slidably connected to it. The sidewall of the mesh groove has groove wall protrusions, and the end of each heat sink pillar inserted into the mesh groove has a pillar wall protrusion located between the bottom of the mesh groove and the groove wall protrusion. For high-current-density vertical power distribution modules with different structures, the heating locations and temperatures on the sidewalls are also different. In practical applications, before packaging the high-current-density vertical power distribution module, the heating locations and temperatures on the sidewalls of the power device 2 can be specifically tested. Based on the different heating locations and temperatures, the heat sink pillars can be slidably positioned to concentrate on locations with higher heating temperatures, while the number of heat sink pillars can be appropriately reduced for locations with lower heating temperatures.

[0047] Furthermore, it should be noted that for the portions of the mesh grooves without heat dissipation pillars, the protruding groove walls effectively increase the heat dissipation area of ​​the heat sink 4, allowing it to function as heat dissipation fins and thus more effectively improve the overall heat dissipation performance of the heat sink 4. Similarly, the protruding pillar walls on the heat dissipation pillars also increase the heat dissipation area of ​​the heat sink 4 and can also be used as heat dissipation fins.

[0048] Specifically, the heat sink 4 can be directly connected to the power device 2 through the insulating thermal conductive layer. This is because the insulating thermal conductive layer has the dual functions of insulation and thermal conductivity. On the one hand, the insulating thermal conductive layer can achieve an insulated connection between the heat sink 4 and the power device 2. On the other hand, it can transfer the heat dissipated by the power device 2 to the heat sink 4, thereby improving the heat dissipation performance of the power device 2.

[0049] For example, the material of the insulating and thermally conductive layer can be a thermally conductive resin material.

[0050] In order to further reduce the area of ​​the power supply and distribution module, in the above-mentioned high current density vertical power supply and distribution module, the side electrode 3, the top electrode 9 and / or the bottom electrode 5 are all input ports of the vertical power supply and distribution module, which can be used as signal ports or power ports. The side electrode 3 connects the top electrode 9 to the packaging substrate 1. The top electrode 9 can realize the vertical stacking of multiple vertical power supply and distribution modules. It should be noted that the side electrode 3 is used as an input port to replace the electrical connector to realize vertical power distribution. The top electrode 9 can be directly soldered without the need for an additional electrical connector.

[0051] For example, the side electrode 3 is directly connected to the metal layer inside the packaging substrate 1, and no additional transition components are provided between them. In this way, on the one hand, the input signal can be transmitted to the inside of the packaging substrate 1, and on the other hand, it can also be used to realize the interconnection between the metal layers inside the packaging substrate 1 to form an integrated metal structure, which helps to reduce the area of ​​the packaging substrate 1.

[0052] It should be noted that the packaging substrate 1 is a multilayer PCB board, which includes multiple layers of metal layers and multiple layers of insulating layers.

[0053] In order to further reduce the size of the high current density vertical power supply and distribution module, the maximum power of the integrated circuit chip 6 shall not exceed 3W, and the maximum power consumption of the power device 2 shall be above 10W.

[0054] It is worth noting that when there is an inductor 10 (e.g., inductor 10 and / or transformer) inside the packaging substrate 1 for energy storage and filtering, the inductor 10 is located between the top electrode 9 and the power device 2. The inductor 10 is mounted on the packaging substrate 1 through the lead bracket 11. The projected area of ​​the inductor 10 on the surface (upper surface, lower surface and / or side surface) of the packaging substrate 1 does not exceed the area of ​​the surface of the packaging substrate 1. The height of the bottom of the inductor 10 from the surface of the packaging substrate 1 needs to be greater than or equal to the mounting height of the power device 2.

[0055] Example 2

[0056] This embodiment provides a packaging process for a high current density vertical power supply and distribution module, used for packaging the high current density vertical power supply and distribution module provided in Embodiment 1. The packaging process includes the following steps:

[0057] Step 1: Provide a first core board 12 and a second core board 13. Embed the integrated circuit chip 6 in the first core board 12 and the passive device 7 in the core board. See [link to relevant documentation]. Figure 3 ;

[0058] Step 2: Press the first core board 12 and the second core board 13 together to form the packaging substrate 1, see [link to documentation]. Figure 4In the process of preparing the packaging substrate 1, compared with directly embedding the integrated circuit chip 6 and the passive device 7 in the same core board, embedding the integrated circuit chip 6 and the passive device 7 in different core boards (i.e., the first core board 12 and the second core board 13) can effectively reduce the area of ​​the packaging substrate 1.

[0059] Step 3: Mechanically drill holes on the upper and lower surfaces of the packaging substrate 1, respectively, and metallize the hole walls (e.g., electroplating). Plug the holes with solder resist. Form a mounting electrode 8 (the mounting electrode is the copper foil on the upper surface of the packaging electrode) on the upper surface of the packaging substrate 1, and form a bottom electrode 5 (the bottom electrode 5 is the copper foil on the lower surface of the packaging substrate 1) on the lower surface of the packaging substrate 1. See [link to documentation]. Figure 5 ;

[0060] Step 4: Sequentially mount the power device 2 and the inductor 10 onto the mounting electrode 8, see [link / reference]. Figure 6 ;

[0061] Step 5: After attaching the heat sink 4 to the side of the power device 2, the entire assembly to be packaged is obtained;

[0062] Step 6: Use potting material (e.g., resin) to pot the entire package to be packaged, ensuring that the package substrate 1, power device 2, heat sink 4, and inductor 10 are completely wrapped by the potting material to obtain the entire package;

[0063] Step 7: Perform four-sided mechanical grinding on the cured package until the heat sink 4 and the sidewalls of the package substrate 1 are exposed;

[0064] Step 8: Metallize the surface of the polished package to form the side electrode 3 and the top electrode 9, thus obtaining a high current density vertical power supply and distribution module.

[0065] Compared with the prior art, the beneficial effects of the packaging process of the high current density vertical power supply and distribution module provided in this embodiment are basically the same as those of the high current density vertical power supply and distribution module provided in Embodiment 1, and will not be described in detail here.

[0066] Specifically, in step 6 above, surface metallization includes the following steps:

[0067] Step 61: Perform chemical copper plating, electroplating, and surface treatment (e.g., OSP, tin plating, ENIG, ENEPIG, etc.) on the polished package in sequence.

[0068] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high current density vertical power supply and distribution module, characterized in that, This includes packaging substrates, power devices, side electrodes, bottom electrodes, top electrodes, integrated circuit chips, and passive devices; The bottom electrode, the packaging substrate, the power device, and the top electrode are stacked sequentially from bottom to top. The side electrode is located on the side of the packaging substrate, and the top electrode is connected to the packaging substrate through the side electrode. The integrated circuit chip and passive device are embedded inside the packaging substrate, and the two are stacked in the vertical direction. The high current density vertical power supply and distribution module also includes an inductor, which is located between the top electrode and the power device; The projected area of ​​the inductor on the surface of the packaging substrate does not exceed the area of ​​the packaging substrate surface, and the height of the bottom of the inductor from the surface of the packaging substrate is greater than or equal to the mounting height of the power device.

2. The high current density vertical power supply and distribution module according to claim 1, characterized in that, It also includes heat sinks located on the side of the power devices.

3. The high current density vertical power supply and distribution module according to claim 2, characterized in that, The heat sink is directly connected to the power device through an insulating and thermally conductive layer.

4. The high current density vertical power supply and distribution module according to claim 3, characterized in that, The insulating and thermally conductive layer is made of thermally conductive resin.

5. The high current density vertical power supply and distribution module according to claim 1, characterized in that, The side electrodes, top electrodes, and / or bottom electrodes serve as signal ports and / or power ports.

6. The high current density vertical power supply and distribution module according to claim 1, characterized in that, The side electrode is directly connected to the metal layer inside the packaging substrate.

7. The high current density vertical power supply and distribution module according to claim 1, characterized in that, The maximum power of the integrated circuit chip does not exceed 3W, and the maximum power consumption of the power device is 10W or more.

8. A packaging process for a high current density vertical power supply and distribution module, characterized in that, For packaging the high current density vertical power supply and distribution module as described in any one of claims 1 to 7, the packaging process includes the following steps: A first core board and a second core board are provided, wherein an integrated circuit chip is embedded in the first core board and a passive device is embedded in the second core board; The first core board and the second core board are pressed together to form an encapsulation substrate; Holes are drilled on the lower surface of the packaging substrate, and the hole walls are metallized. Solder resist is used to plug the holes, and a bottom electrode is formed on the lower surface of the packaging substrate to obtain the whole package. The entire package to be packaged is encapsulated to obtain the packaged product. Grind the entire package until the sidewalls of the package substrate are exposed; The surface of the polished package is metallized to form side electrodes and top electrodes, resulting in a high current density vertical power supply and distribution module.

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