Packaging structure for embedding power device into circuit board

Abstract

The utility model relates to the technical field of circuit board packaging structures, in particular to a packaging structure for embedding a power device into a circuit board, which is mainly characterized in that the power device is embedded into an outer layer board, and the outer layer board comprises a power Cell, a conductive layer, an insulating layer, a metal blind filling hole, a high-thermal-conductivity insulating layer and a solder mask layer. The outer layer plate can be selectively connected with the radiator through a welding or sintering process. On the basis of a circuit board process, the power chip is embedded into the circuit board, so that the on-resistance can be reduced, the on-loss can be reduced, the parasitic inductance can be reduced, the switching loss can be reduced, the thermal resistance can be reduced, and the current output capability of a single device can be improved. According to the utility model, the latest laminated design is adopted, the power device is embedded in the circuit board, and compared with a common chip embedded circuit board in the market, metal blind filling holes connected with the drain electrode of the power device are all replaced by electroplating copper, so that the conduction and switching loss is further reduced, and the thermal resistance is further reduced by more than 10%.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit board packaging structures, in particular to a circuit board packaging structure in which a power device is embedded. Background Art

[0002] With the development and widespread adoption of new energy vehicles and high-power industrial electronics, motor controllers, as core components of electric drives, are becoming increasingly important. Traditional motor controller design approaches are no longer able to meet the growing demand, and performance is gradually reaching bottlenecks. With the continuous development of third-generation semiconductors, the requirements for motor controller power density, integration, and reliability are becoming increasingly stringent.

[0003] To solve the above problems, power device embedded circuit boards are a potential solution. However, the common power device embedded circuit board solutions on the market all use copper-plated blind holes to achieve electrical and thermal conductivity. This results in high on-resistance of the package, large conduction loss, and still relatively large thermal resistance.

[0004] Therefore, a power device embedded in a circuit board packaging structure is proposed. Utility Model Content

[0005] The purpose of the present utility model is to provide a power device embedded in a circuit board packaging structure to solve the problems raised by the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A power device embedded in a circuit board packaging structure, wherein the power device is embedded in an outer layer board, the outer layer board includes a power cell, a conductive layer, an insulating layer, a metal-filled blind hole, a high thermal conductivity insulating layer and a solder resist layer, and the outer layer board can be connected to the heat sink by welding or sintering;

[0008] The power cell is composed of power devices and copper concave blocks;

[0009] The power device is fixedly connected to the inside of the copper concave block;

[0010] The insulating layer is fixedly connected to the conductive layer, an empty slot is opened inside the insulating layer, and the power cell is fixedly connected inside the empty slot;

[0011] A metal-filled blind hole is provided on the insulating layer, a high thermal conductivity insulating layer is fixedly connected under the conductive layer, and an insulating gap is provided on the conductive layer;

[0012] A solder resist layer is fixedly connected to the conductive layer.

[0013] Preferably, the bonding method of the power device and the copper concave block includes but is not limited to silver sintering, copper sintering, and diffusion welding.

[0014] Preferably, the power devices include but are not limited to: Si MOSFET, SiC MOSFET, Si IGBT, GaNMOSFET and other power devices.

[0015] Preferably, the electrical performance of the power device is achieved by metal-filled blind holes and a conductive layer.

[0016] Preferably, the copper recess needs to carry at least but not limited to one power device.

[0017] Preferably, the lower portion of the copper concave block is directly connected to the conductive layer.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This new design, based on circuit board technology, embeds power chips within the circuit board. This reduces on-resistance and thus conduction losses, reduces parasitic inductance and thus switching losses, and reduces thermal resistance, thereby increasing the current output capability of a single device. This new design utilizes a state-of-the-art stacked design to embed the power device within the circuit board. Compared to common chip-embedded circuit boards on the market, the metal-filled blind vias connecting to the power device drain are completely replaced with electroplated copper. This not only further reduces conduction and switching losses, but also lowers thermal resistance by over 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the utility model;

[0021] Figure 2 This is a schematic diagram of the power cell structure of the present utility model;

[0022] Figure 3 This is a schematic diagram of the inner plate structure of the present utility model;

[0023] Figure 4 This is a schematic diagram of the secondary outer layer bare plate structure of the present utility model;

[0024] Figure 5 This is a schematic diagram of the metal-filled blind hole position of the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of the secondary outer layer plate of the present utility model;

[0026] Figure 7 This is a schematic diagram of the outer bare plate structure of the utility model;

[0027] Figure 8 This is a schematic diagram of the outer plate structure of the present invention.

[0028] In the picture:

[0029] 1. Power device; 2. Copper concave block; 3. Conductive layer; 4. Insulation layer; 5. Empty slot; 6. Insulation gap; 7. Metal-filled blind via; 8. High thermal conductivity insulation layer; 9. Solder mask layer; 10. Heat sink; 11. Welding or sintering layer. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0032] like Figure 1-3 As shown, the present application provides a power device embedded in a circuit board packaging structure, including: an outer layer board, a heat sink 10, the outer layer board includes a power cell, a conductive layer 3, an insulating layer 4, a metal-filled blind hole 7, a high thermal conductivity insulating layer 8 and a solder resist layer 9, and the outer layer board is welded or sintered on the heat sink 10 to form a welding or sintering layer 11;

[0033] The power cell consists of a power device 1 and a copper concave block 2;

[0034] The power device 1 is fixedly connected to the inside of the copper concave block 2;

[0035] The insulating layer 4 is fixedly connected to the conductive layer 3. A slot 5 is provided inside the insulating layer 4. The power cell is fixedly connected inside the slot 5.

[0036] A metal-filled blind hole 7 is provided on the insulating layer 4, a high thermal conductivity insulating layer 8 is fixedly connected under the conductive layer 3, and an insulating gap 6 is provided on the conductive layer 3;

[0037] A solder resist layer 9 is fixedly connected to the conductive layer 3 .

[0038] In this embodiment: one or more power devices 1 are combined with a copper concave block 2 to form a semi-finished power cell. The combination method includes, but is not limited to, silver sintering, copper sintering, and diffusion welding. The core board composed of a conductive layer 3 and an insulating layer 4 is etched with an insulating gap 6 according to the design, and a slot 5 is made in the conductive core board to form an inner layer board. The power cell is placed in the slot 5, and its lower part protrudes from the inner layer board. The insulating layer 4 and the conductive layer 3 are stacked on the upper part, and the insulating layer 4 and the conductive layer 3 are also stacked on the lower part. The lower insulating layer 4 and the conductive layer 3 need to be opened to allow the protruding part of the power cell to pass through them, and then pressed together. After the pressing is completed, the bottom end of the power cell and the lower end conductive layer 3 are kept at the same level as much as possible, or slightly protruded, thereby forming a sub-outer bare board, and the sub-outer bare board is pierced by laser. Micro blind holes are made in the upper and lower conductive layers 3 and the insulating layer 4 on the outermost sides, and conductor metal is electroplated into the micro blind holes to form metal-filled blind holes 7, so that the power device 1, the copper concave block 2 and the conductive layer 3, as well as the conductive layer 3 and the conductive layer 3 are interconnected. The electroplating process simultaneously increases the thickness of the conductive layer 3 on the upper and lower sides, and connects the copper concave block 2 with the lower end conductive layer 3 as a whole. An insulating gap 6 is etched in the upper and lower conductive layers 3 to form a sub-outer layer board. The insulating layer 4 and the conductive layer 3 are stacked on the sub-outer layer board, and the high thermal conductivity insulating layer 8 and the conductive layer 3 are stacked below and pressed together to form an outer bare board. The conductive layer 3 on the outer bare board is etched with an insulating gap 6 according to the design, and a solder resist layer 9 is made on the upper conductive layer 3 to form an outer board. Afterwards, the outer board can be sintered or welded to the heat sink 10.

[0039] The power device 1 includes but is not limited to: Si MOSFET, SiC MOSFET, Si IGBT, GaN MOSFET and other power devices 1.

[0040] The electrical performance of the power device 1 is achieved through the metal-filled blind vias 7 and the conductive layer 3 .

[0041] The copper recess 2 needs to support at least but not limited to one power device 1 .

[0042] Furthermore, it should be noted that:

[0043] The power device 1 is embedded in the circuit board package, which is a circuit board with multiple conductive layers 3 (it can also be a single layer, in which case the power device 1 is placed on top of the conductive layer), with insulating material filling between the layers, and the power device 1 placed in the circuit board;

[0044] The power device 1 is embedded in the circuit board body through the circuit board manufacturing process. The electrical performance of the power device 1 is achieved through the metal-filled blind via 7 and the conductive layer 3. The main heat is conducted to the heat sink 10 through the copper concave block 2, the high thermal conductivity insulating material and the lower conductive layer 3.

[0045] The present invention includes directly embedding the power device 1, and embedding the power device 1 after pre-packaging. Pre-packaging includes, but is not limited to, sintering or welding the power device 1 on the copper concave block 2. A copper concave block 2 needs to carry at least, but not limited to, one power device 1.

[0046] The main body of the utility model is a circuit board, which can be a single-layer circuit board, a double-layer circuit board, a three-layer circuit board, or a circuit board with any number of layers;

[0047] The bottom of the copper concave block 2 of the utility model is directly connected to the conductive layer 3 without any characteristic medium in between;

[0048] The utility model can selectively integrate and embed the power copper terminal (copper block) in the circuit board;

[0049] Compared with many advanced packages that embed power chips into circuit boards, the present invention not only has smaller conduction losses, but also can reduce thermal resistance by more than 10%.

[0050] Working principle: Based on the circuit board process, the power chip is embedded in the circuit board, and the chip function is led out through the metal-filled blind via 7 and the conductive layer 3, which reduces the on-resistance and thus reduces the conduction loss, reduces the parasitic inductance and thus reduces the switching loss. Heat is conducted out through the copper concave block 2, the high thermal conductivity insulating material and the lower conductive layer 3. Each material has a high thermal conductivity, and the stacked structure has a short thermal conduction path, thereby reducing thermal resistance and increasing the current output capacity of a single device. The utility model adopts the latest stacking design to embed the power device 1 into the circuit board. Compared with the common chip-embedded circuit boards on the market, the metal-filled blind vias 7 connected to the drain of the power device 1 are all replaced with electroplated copper, which not only further reduces the conduction loss, but also further reduces the thermal resistance by more than 10%.

[0051] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative; within the spirit of the present invention, the technical features of the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0052] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A power device embedded in a circuit board packaging structure, characterized in that: The power device is embedded in an outer layer board, wherein the outer layer board comprises a power cell, a conductive layer (3), an insulating layer (4), a metal-filled blind hole (7), a high thermal conductivity insulating layer (8) and a solder resist layer (9); the outer layer board can be selectively soldered or sintered on a heat sink (10) to form a soldering or sintering layer (11); The power cell is composed of a power device (1) and a copper concave block (2); The power device (1) is fixedly connected inside the copper concave block (2); The insulating layer (4) is fixedly connected to the conductive layer (3), a slot (5) is provided inside the insulating layer (4), and the power cell is fixedly connected inside the slot (5); A metal-filled blind hole (7) is provided on the insulating layer (4), a high-thermal-conductivity insulating layer (8) is fixedly connected below the conductive layer (3), and an insulating gap (6) is provided on the conductive layer (3); A solder resist layer (9) is fixedly connected to the conductive layer (3).

2. The power device embedded circuit board packaging structure according to claim 1, characterized in that: The combination method of the power device (1) and the copper concave block (2) includes silver sintering, copper sintering, and diffusion welding.

3. The power device embedded circuit board packaging structure according to claim 2, characterized in that: The power device (1) includes but is not limited to: SiMOSFET, SiC MOSFET, SiIGBT, GaN MOSFET.

4. The power device embedded circuit board packaging structure according to claim 3, characterized in that: The electrical performance of the power device (1) is achieved through the metal-filled blind hole (7) and the conductive layer (3).

5. The power device embedded circuit board packaging structure according to claim 4, characterized in that: The copper concave block (2) needs to carry at least, but not limited to, one power device (1).

6. The power device embedded circuit board packaging structure according to claim 5, characterized in that: The lower part of the copper concave block (2) is directly connected to the conductive layer (3).

Images