High bonding strength ceramic substrate

Abstract

The utility model discloses a high-bonding strength ceramic substrate, including a lower ceramic layer, an upper ceramic layer, a metal clamp and a plurality of fixed connectors; the lower surface of the lower ceramic layer is concavely provided with a plurality of first countersunk holes, and the bottom center of each first countersunk hole is provided with a first through hole; the upper ceramic layer is located directly above the lower ceramic layer, and the upper surface of the upper ceramic layer is concavely provided with a plurality of second countersunk holes, and the bottom center of each second countersunk hole is provided with a second through hole; the metal clamp is clamped and overlapped and fixed between the lower ceramic layer and the upper ceramic layer. By designing a plurality of fixed connectors to be heat-conductive carbon fiber materials, and each fixed connector is fixedly formed in a corresponding accommodating cavity, the lower ceramic layer, the upper ceramic layer and the metal clamp are firmly combined together, the bonding strength is effectively improved, and separation from stratification is not likely to occur, thereby ensuring thermal conductivity and improving the overall performance of the product.

Description

Technical Field

[0001] The utility model relates to the field of ceramic substrate technology, in particular to a high-bonding-strength ceramic substrate. Background Art

[0002] Ceramic substrate refers to a special process board in which copper foil is directly bonded to the surface (single or double sides) of alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate at high temperature. The ultra-thin composite substrate has excellent electrical insulation performance, high thermal conductivity, excellent soft solderability and high adhesion strength. It can be etched with various patterns like PCB boards and has a large current carrying capacity. Therefore, ceramic substrate has become the basic material for high-power power electronic circuit structure technology and interconnection technology.

[0003] Ceramic substrates are widely used in various electronic devices to package various electronic devices with high heat generation. In the prior art, the main structure of a ceramic substrate used to package electronic devices includes a ceramic substrate body and a conductive circuit layer; the conductive circuit layer is arranged on the surface of the ceramic substrate body by copper coating. When in use, the electronic device is placed on the surface of the ceramic substrate body and is welded to the conductive circuit layer.

[0004] At present, the ceramic substrate bodies on the market are generally single-layer structures. Due to the high brittleness of the ceramic material, the ceramic substrate is prone to breakage and damage. For this reason, there are also ceramic substrates with sandwich structures, that is, a metal sandwich plate is sandwiched between the upper and lower ceramic layers, which can solve the above problems well. However, this ceramic substrate metal sandwich plate is only bonded to the two ceramic layers by thermal conductive adhesive, and the bonding strength is relatively low, and it is easy to separate and delaminate, thereby affecting the thermal conductivity. Therefore, it is necessary to improve the current ceramic substrate. Utility Model Content

[0005] In view of this, the present invention aims at the deficiencies in the prior art, and its main purpose is to provide a high bonding strength ceramic substrate, which can effectively solve the problem of relatively low bonding strength of the existing ceramic substrates.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A high bonding strength ceramic substrate comprises a lower ceramic layer, an upper ceramic layer, a metal clamping plate and a plurality of fixing connecting parts;

[0008] The lower surface of the lower ceramic layer is concavely provided with a plurality of first countersunk holes, and a first through hole is opened at the center of the bottom surface of each first countersunk hole, and the first through hole penetrates to the upper surface of the lower ceramic layer, and the inner diameter of the first through hole is smaller than the inner diameter of the first countersunk hole;

[0009] The upper ceramic layer is located directly above the lower ceramic layer, and a plurality of second countersunk holes are recessed on the upper surface of the upper ceramic layer. A second through hole is opened at the center of the bottom surface of each second countersunk hole, and the second through hole penetrates to the lower surface of the upper ceramic layer, and the inner diameter of the second through hole is smaller than the inner diameter of the second countersunk hole; a conductive circuit layer is formed on the upper surface of the upper ceramic layer;

[0010] The metal clamp is clamped and fixed between the lower ceramic layer and the upper ceramic layer. A plurality of third through holes are formed through the upper and lower surfaces of the metal clamp. Each third through hole is connected to the corresponding first through hole and the corresponding second through hole to form a receiving cavity.

[0011] The plurality of fixed connecting members are all made of heat-conductive carbon fiber material, and each fixed connecting member is fixedly formed in a corresponding accommodating cavity.

[0012] As a preferred solution, the lower ceramic layer is fixed to the lower surface of the metal clamping plate by laminating and bonding through a first thermally conductive adhesive layer to improve the bonding strength between the metal clamping plate and the lower ceramic layer and ensure thermal conductivity.

[0013] As a preferred solution, the upper ceramic layer is fixed to the upper surface of the metal clamping plate by laminating and bonding through a second thermally conductive adhesive layer to improve the bonding strength between the metal clamping plate and the upper ceramic layer and ensure thermal conductivity.

[0014] As a preferred solution, both sides of the metal clamp are bent and extended to form fixing feet, which are L-shaped and fit with the outer side surface of the lower ceramic layer. The bottom surface of the fixing foot is flush with the bottom surface of the lower ceramic layer. Fixing holes are provided on the fixing foot so that it can be directly installed and fixed to the equipment chassis by screws and connected, thereby realizing the fixing and grounding functions.

[0015] As a preferred solution, a rough layer is formed on the upper surface of the upper ceramic layer, and the conductive circuit layer includes a tungsten metal layer and a copper metallization layer. The tungsten metal layer is formed on the surface of the rough layer by electroplating, and the copper metallization layer is formed on the surface of the tungsten metal layer by electroplating, so that the bonding strength between the conductive circuit layer and the upper ceramic layer is higher and it is not easy to delaminate.

[0016] As a preferred solution, the lower ceramic layer and the upper ceramic layer are both made of aluminum nitride ceramic material, which has good thermal conductivity.

[0017] As a preferred embodiment, the upper surface of the upper ceramic layer is provided with a cavity for positioning the electronic device, the fixed connector is located on the side of the cavity, and a grounding electrode is embedded and fixed in the fixed connector, and the grounding electrode is exposed on the upper surface of the fixed connector so that the electronic device can be welded to the grounding electrode for grounding.

[0018] Compared with the prior art, the utility model has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0019] By designing multiple fixed connectors to be made of thermally conductive carbon fiber material, and each fixed connector is fixedly formed in the corresponding accommodating cavity, the lower ceramic layer, the upper ceramic layer and the metal splint are firmly combined together, the bonding strength is effectively improved, and detachment and delamination are not likely to occur, thereby ensuring thermal conductivity and improving the overall performance of the product.

[0020] In order to more clearly illustrate the structural features and functions of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of a preferred embodiment of the utility model.

[0022] Description of the accompanying drawings:

[0023] 10. Lower ceramic layer 11. First sink hole

[0024] 12. First through hole 101, accommodating cavity

[0025] 20. Upper ceramic layer 21. Second sink hole

[0026] 22. Second through hole 23. Concave cavity

[0027] 24. Rough layer 25. Graphene coating

[0028] 30. Metal clamping plate 31. Third through hole

[0029] 32. Fixed foot 321. Fixed hole

[0030] 40. Fixed connection piece 50. Conductive circuit layer

[0031] 51. Tungsten metal layer 52. Copper metallization layer

[0032] 61. First thermal conductive adhesive layer 62. Second thermal conductive adhesive layer

[0033] 70. Ground electrode 71. Base

[0034] 72. Fixed part. DETAILED DESCRIPTION

[0035] Please refer to Figure 1 As shown, it shows the specific structure of a preferred embodiment of the utility model, including a lower ceramic layer 10, an upper ceramic layer 20, a metal clamping plate 30 and a plurality of fixing connectors 40.

[0036] The lower surface of the lower ceramic layer 10 is concavely provided with a plurality of first countersunk holes 11, and a first through hole 12 is opened at the center of the bottom surface of each first countersunk hole 11, and the first through hole 12 penetrates to the upper surface of the lower ceramic layer 10, and the inner diameter of the first through hole 12 is smaller than the inner diameter of the first countersunk hole 11. In this embodiment, the lower ceramic layer 10 is made of aluminum nitride ceramic material, which has good thermal conductivity; the plurality of first countersunk holes 11 are located at the edge of the lower ceramic layer 10.

[0037] The upper ceramic layer 20 is located directly above the lower ceramic layer 10. A plurality of second countersunk holes 21 are recessed on the upper surface of the upper ceramic layer 20. A second through hole 22 is opened at the center of the bottom surface of each second countersunk hole 21. The second through hole 22 penetrates to the lower surface of the upper ceramic layer 20. The inner diameter of the second through hole 22 is smaller than the inner diameter of the second countersunk hole 21. A conductive circuit layer 50 is formed on the upper surface of the upper ceramic layer 20. In this embodiment, the upper ceramic layer 20 is made of aluminum nitride ceramic material with good thermal conductivity. The plurality of second countersunk holes 21 are located at the edge of the upper ceramic layer 20. A concave cavity 23 for positioning electronic components is recessed on the upper surface of the upper ceramic layer 20 to facilitate the installation and fixing of electronic components. Furthermore, the upper surface of the upper ceramic layer 20 is formed with a rough layer 24 by grinding, and the conductive circuit layer 50 includes a tungsten metal layer 51 and a copper metallization layer 52. The tungsten metal layer 51 is formed on the surface of the rough layer 24 by electroplating, and the copper metallization layer 52 is formed on the surface of the tungsten metal layer 51 by electroplating, so that the bonding strength between the conductive circuit layer 50 and the upper ceramic layer 20 is higher and it is not easy to delaminate. In addition, the inner wall of the cavity 23 is coated with a graphene coating 25 to improve the thermal conductivity efficiency.

[0038] The metal clamp 30 is clamped, overlapped and fixed between the lower ceramic layer 10 and the upper ceramic layer 20. A plurality of third through holes 31 are formed through the upper and lower surfaces of the metal clamp 30. Each third through hole 31 connects the corresponding first through hole 12 and the corresponding second through hole 22 to form a receiving cavity 101. In this embodiment, the metal clamp 30 is a copper-aluminum composite metal plate with good structural strength and excellent thermal and electrical conductivity. In addition, the lower ceramic layer 10 is overlapped and bonded to the lower surface of the metal clamp 30 by the first thermal conductive adhesive layer 61 to improve the bonding strength between the metal clamp 30 and the lower ceramic layer 10 and ensure thermal conductivity. The upper ceramic layer 20 is overlapped and bonded to the upper surface of the metal clamp 30 by the second thermal conductive adhesive layer 62 to improve the bonding strength between the metal clamp 30 and the upper ceramic layer 20 and ensure thermal conductivity. In addition, both sides of the metal clamp 30 are bent and extended to form fixing feet 32, which are L-shaped and fit against the outer side surface of the lower ceramic layer 10. The bottom surface of the fixing foot 32 is flush with the bottom surface of the lower ceramic layer 10. The fixing foot 32 is provided with a fixing hole 321 so that it can be directly installed and fixed to the equipment chassis by screws and connected, thereby realizing the fixing and grounding functions.

[0039] The plurality of fixed connectors 40 are all made of heat-conductive carbon fiber material, and each fixed connector 40 is fixedly formed in the corresponding accommodation cavity 101. In the present embodiment, the fixed connector 40 is in an I-shape, and is located beside the concave cavity 23, and a grounding electrode 70 is fixedly embedded in the fixed connector 40, and the grounding electrode 70 is exposed on the upper surface of the fixed connector 40, so that the electronic device can be grounded by welding with the grounding electrode 70, and the grounding electrode 70 is made of copper material, which is formed by lathing, and the grounding electrode 70 includes a base 71 and a fixing portion 72 extending downward from the bottom surface of the base 71, and the base 71 is disc-shaped and exposes the upper surface of the fixed connector 40, so that the grounding pin of the electronic device can be welded, and the fixing portion 72 is in an inverted T-shape, which is buried in the fixed connector 40, so that the grounding electrode 70 and the fixed connector 40 are firmly and reliably combined.

[0040] The production process of this embodiment is described in detail as follows:

[0041] During the production, first, prepare the lower ceramic layer 10, the upper ceramic layer 20 and the metal clamp 30, the upper surface of the upper ceramic layer 20 is formed and fixed with a conductive circuit layer 50, then, apply thermal conductive adhesive on the upper and lower surfaces of the metal clamp 30, then, stack the upper ceramic layer 20 and the lower ceramic layer 10 on the upper surface of the metal clamp 30 respectively, so that the upper ceramic layer 20 and the lower ceramic layer 10 are respectively bonded to the upper and lower surfaces of the metal clamp 30 by thermal conductive adhesive, then, fill the accommodating cavity 101 with uncured thermal conductive carbon fibers, and embed the ground electrode 70 on the uncured thermal conductive carbon fibers, then, heat the thermal conductive carbon fibers so that the thermal conductive carbon fibers are cured to form a fixed connector 40, which firmly combines the lower ceramic layer 10, the upper ceramic layer 20 and the metal clamp 30 together and is not easy to separate.

[0042] When in use, the electronic device is embedded in the cavity 23 and fixed, and the ground pin of the electronic device is welded to the ground electrode 70 , and the other pins are welded to the conductive circuit layer 50 .

[0043] The design focus of the utility model is: by designing multiple fixed connecting parts to be made of heat-conductive carbon fiber material, and each fixed connecting part is fixedly formed in the corresponding accommodating cavity, the lower ceramic layer, the upper ceramic layer and the metal splint are firmly combined together, the bonding strength is effectively improved, and it is not easy to separate from the layer, thereby ensuring the thermal conductivity and improving the overall performance of the product.

[0044] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high bonding strength ceramic substrate, characterized in that: It includes a lower ceramic layer, an upper ceramic layer, a metal clamping plate and a plurality of fixing connecting parts; The lower surface of the lower ceramic layer is concavely provided with a plurality of first countersunk holes, and a first through hole is opened at the center of the bottom surface of each first countersunk hole, and the first through hole penetrates to the upper surface of the lower ceramic layer, and the inner diameter of the first through hole is smaller than the inner diameter of the first countersunk hole; The upper ceramic layer is located directly above the lower ceramic layer, and a plurality of second countersunk holes are recessed on the upper surface of the upper ceramic layer. A second through hole is opened at the center of the bottom surface of each second countersunk hole, and the second through hole penetrates to the lower surface of the upper ceramic layer, and the inner diameter of the second through hole is smaller than the inner diameter of the second countersunk hole; a conductive circuit layer is formed on the upper surface of the upper ceramic layer; The metal clamp is clamped and fixed between the lower ceramic layer and the upper ceramic layer. A plurality of third through holes are formed through the upper and lower surfaces of the metal clamp. Each third through hole is connected to the corresponding first through hole and the corresponding second through hole to form a receiving cavity. The plurality of fixed connecting members are all made of heat-conductive carbon fiber material, and each fixed connecting member is fixedly formed in a corresponding accommodating cavity.

2. The high bonding strength ceramic substrate according to claim 1, characterized in that: The lower ceramic layer is fixed on the lower surface of the metal clamping plate by laminating and bonding through the first heat-conducting adhesive layer.

3. The high bonding strength ceramic substrate according to claim 1, characterized in that: The upper ceramic layer is fixed on the upper surface of the metal clamping plate by laminating and bonding through a second heat-conducting adhesive layer.

4. The high bonding strength ceramic substrate according to claim 1, characterized in that: Both sides of the metal clamp are bent and extended to form fixing feet, which are L-shaped and fit with the outer side of the lower ceramic layer. The bottom surface of the fixing foot is flush with the bottom surface of the lower ceramic layer, and a fixing hole is opened on the fixing foot.

5. The high bonding strength ceramic substrate according to claim 1, characterized in that: A rough layer is formed on the upper surface of the upper ceramic layer. The conductive circuit layer includes a tungsten metal layer and a copper metallization layer. The tungsten metal layer is formed on the surface of the rough layer by electroplating, and the copper metallization layer is formed on the surface of the tungsten metal layer by electroplating.

6. The high bonding strength ceramic substrate according to claim 1, characterized in that: The lower ceramic layer and the upper ceramic layer are both made of aluminum nitride ceramic material.

7. The high bonding strength ceramic substrate according to claim 1, characterized in that: The upper surface of the upper ceramic layer is provided with a cavity for positioning electronic components, the fixed connector is located beside the cavity, and a grounding electrode is embedded and fixed in the fixed connector, and the grounding electrode is exposed from the upper surface of the fixed connector.

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