Multi-layer composite heat dissipation substrate

Abstract

A multi-layer composite heat dissipation substrate comprises a core substrate, a first insulating layer, a first electrode layer, a second electrode layer and a solder layer. The core substrate has a first surface and a second surface. The first insulating layer is formed on the first surface of the core substrate, and the first insulating layer is located between the core substrate and the first electrode layer. The first insulating layer is made of an insulating material selected from the group consisting of a nitride, an oxide, and a nitrogen oxide. The first electrode layer is formed on the top surface of the first insulating layer. The second electrode layer is located below the core substrate. The solder layer is formed on the top surface of the first electrode layer. Therefore, when the chip is arranged on the solder layer for operation, heat dissipation can be effectively carried out on the chip.

Description

Technical Field

[0001] The present invention relates to a heat dissipation substrate, in particular to a multi-layer composite heat dissipation substrate, which is used to carry a high-power chip, such as a laser chip, to dissipate heat. Background Art

[0002] Laser chips, also known as laser diodes, are primarily used in fiber optic communications, biosensing, and industrial sensing. During operation, laser chips are typically mounted on a heat sink substrate to form a laser light source module. This heat sink substrate helps dissipate heat from the laser chip. Conventional heat sink substrates consist of an insulating substrate and two electrode layers, one on each side of the insulating substrate.

[0003] The existing connection between the heat dissipation substrate and the laser chip is prone to thermal stress due to the poor matching of thermal expansion coefficients. Heat conduction is also limited, which easily affects the performance and life of the high-power laser chip.

[0004] Therefore, how to improve the overall heat dissipation effect of the heat dissipation substrate and the matching degree between the heat dissipation substrate and the laser chip through structural design improvements to overcome the above-mentioned defects has become an important issue to be solved in this technical field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a multi-layer composite heat dissipation substrate to improve the overall heat dissipation effect of the heat dissipation substrate in response to the shortcomings of the prior art.

[0006] In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a multi-layer composite heat dissipation substrate, which includes a core substrate, a first insulating layer, a first electrode layer, a second electrode layer, and a solder layer.

[0007] The core substrate has a first surface and a second surface. A first insulating layer is formed on the first surface of the core substrate, the first insulating layer being located between the core substrate and the first electrode layer. The first insulating layer is made of an insulating material selected from the group consisting of a nitride, an oxide, and an oxynitride. The first electrode layer is formed on top of the first insulating layer. The second electrode layer is located below the core substrate. A solder layer is formed on top of the first electrode layer.

[0008] According to one embodiment of the present application, the core substrate is made of a material selected from the group consisting of: conductive silicon carbide, semi-insulating silicon carbide, ceramic, diamond-metal hybrid, and diamond.

[0009] According to one embodiment of the present application, the second electrode layer is formed on the second surface of the core substrate.

[0010] According to an embodiment of the present application, the first insulating layer is formed by sputtering, electron beam evaporation, chemical vapor deposition, or sol-gel method.

[0011] According to one embodiment of the present application, the multilayer composite heat dissipation substrate further includes a second insulating layer, which is formed between the second surface of the core substrate and the second electrode layer, wherein the second insulating layer is made of an insulating material selected from the group consisting of: nitride, oxide, and oxynitride.

[0012] According to an embodiment of the present application, the second insulating layer is formed by sputtering, electron beam evaporation, chemical vapor deposition, or sol-gel method.

[0013] According to an embodiment of the present application, the nitride is silicon nitride or aluminum nitride, the oxide is silicon dioxide or aluminum oxide, and the oxynitride is silicon oxynitride or aluminum oxynitride.

[0014] According to one embodiment of the present application, the first electrode layer is selected from a group consisting of: gold / nickel / copper, gold / palladium / nickel / copper, and gold / platinum / titanium, and the first electrode layer is formed by electroplating, sputtering, evaporation, or chemical vapor deposition.

[0015] According to one embodiment of the present application, the second electrode layer is selected from a group consisting of: gold / nickel / copper, gold / palladium / nickel / copper, and gold / platinum / titanium, and the second electrode layer is formed by electroplating, sputtering, evaporation, or chemical vapor deposition.

[0016] According to one embodiment of the present application, the solder layer is selected from the group consisting of: gold / gold tin / platinum / titanium, gold / gold tin / platinum, and gold / gold tin, and the solder layer is formed by electroplating, sputtering, evaporation, or chemical vapor deposition.

[0017] One of the beneficial effects of the present invention is that the multi-layer composite heat dissipation substrate provided by the present invention can be achieved through a technical solution of a core substrate, a first insulating layer, a first electrode layer, a second electrode layer, and a solder layer, wherein the insulating layer is located between the core substrate and the electrode layer. Compared with existing ceramic substrates, it has higher thermal conductivity, thereby improving the heat dissipation effect for high-power chips.

[0018] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and illustration and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1FIG. 1 is a cross-sectional schematic diagram of a first embodiment of a multi-layer composite heat dissipation substrate according to the present invention.

[0020] Figure 2 FIG. 1 is a cross-sectional schematic diagram of a second embodiment of the multi-layer composite heat dissipation substrate of the present invention. DETAILED DESCRIPTION

[0021] The following is an explanation of the disclosed embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted in actual size. It is stated in advance. The following embodiments will further explain the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0022] [First embodiment]

[0023] like Figure 1 As shown, the present invention provides a multi-layer composite heat dissipation substrate, which includes a core substrate 10 , a first insulating layer 20 , a first electrode layer 30 , a second electrode layer 40 , and a solder layer 50 .

[0024] The core substrate 10 has a first surface 11 and a second surface 12. In the diagram of this embodiment, the first surface 11 is the upper surface and the second surface 12 is the lower surface. The core substrate 10 can be selected from conductive (N-type) silicon carbide (SiC), semi-insulating silicon carbide (SiC), ceramic, diamond, or a diamond-metal mixture, but is not limited thereto. Among them, the core substrate 10 composed of diamond can have a higher thermal conductivity than the core substrate 10 composed of silicon carbide (SiC) or ceramic. The core substrate 10 composed of a diamond-metal mixture can, for example, be a diamond substrate doped with metal, such as a high thermal conductivity copper-based diamond composite doped with copper. This can achieve good thermal conductivity and reduce costs compared to a core substrate 10 composed of pure diamond.

[0025] The first insulating layer 20 is formed on the first surface 11 of the core substrate 10. In this embodiment, the first insulating layer 20 may be composed of a nitride, an oxide, or an oxynitride. Specifically, a nitride may be, for example, silicon nitride (SiN) or aluminum nitride (AlN). An oxide may be, for example, silicon dioxide (SiO2) or aluminum oxide (AlO). An oxynitride refers to a compound containing nitrogen, oxygen, and other elements, and may be, for example, silicon oxynitride (SiON) or aluminum oxynitride (AlON).

[0026] The method of bonding the first insulating layer 20 to the core substrate 10 in this embodiment is described below. The first insulating layer 20 can be deposited on the core substrate 10 by sputtering, electron beam evaporation, or chemical vapor deposition to form a nitride, oxide, or oxynitride.

[0027] Regarding the method of forming the first insulating layer 20 on the core substrate 10 by sputtering, for example, aluminum oxide is used as a target. Since aluminum oxide is an insulating material, a high-frequency sputtering device can be used to form the sputtered aluminum oxide film. The aluminum oxide target is bonded to an electrode, and the core substrate 10 is placed on the counter electrode of the electrode. Sputtering discharge is performed under reduced pressure in an atmosphere such as argon, thereby depositing aluminum oxide on the core substrate 10.

[0028] Regarding the method for forming the first insulating layer 20 on the core substrate 10 by electron beam evaporation (EBE), for example, using aluminum oxide as the target, EBE converts the kinetic energy of a high-energy electron beam into thermal energy to melt the target. The saturated vapor pressure of the target near its melting point is then utilized for film deposition. EBE allows for precise control of the deposition rate, enabling the deposition of materials such as nitrides, oxides, and oxynitrides. Furthermore, the core substrate 10 does not require heating to achieve thin film growth.

[0029] In addition, thermal evaporation is also a possible method, which uses a thermal resistance heating method, where the target (first insulating layer 20) is in direct contact with the heating source (usually a tungsten boat). In comparison, electron beam evaporation has a better thermal conversion efficiency.

[0030] Regarding the method of forming the first insulating layer 20 on the core substrate 10 by chemical vapor deposition (CVD), the process involves exposing the core substrate 10 to one or more precursors, causing chemical reactions and / or chemical decomposition on the surface of the core substrate 10 to produce the desired thin film. There are different types of CVD, and the appropriate method can be selected based on the material.

[0031] However, the present invention is not limited thereto. For example, the first insulating layer 20 may also be formed using a sol-gel process. The sol-gel process uniformly disperses various precursor ions in a solvent on the surface of the core substrate 10. An aluminum oxide film can then be spin-coated onto the surface of the core substrate 10 to serve as a buffer layer for surface flatness.

[0032] This embodiment can further improve the thermal conductivity of the multi-layer composite heat dissipation substrate through the first insulating layer 20. Specifically, the material of the insulating layer of this embodiment has a thermal expansion coefficient similar to that of the core substrate 10 and can be well bonded to the core substrate 10. In addition, the insulating layer has a high thermal conductivity and can conduct the heat received by the electrode layer to the core substrate 10. On the other hand, it can improve the thermal expansion coefficient of the entire heat dissipation substrate and the epitaxial layer (5×10 -6 / ℃) matching. For example, aluminum nitride coated on the surface of the core substrate 10 can improve the flatness and smoothness of the surface. Aluminum nitride (AlN) has a high thermal conductivity (170~230w / m·K), and a thermal expansion coefficient (3.5~5.7×10^(-6) / ℃) that matches well with materials such as epitaxial layers, or silicon, or silicon carbide, thereby being well combined with the core substrate of silicon carbide and conducting heat. In addition, the thermal expansion coefficient of silicon nitride is about (3.0×10^(-6) / ℃), which matches well with materials such as silicon and silicon carbide, and the thermal conductivity can reach 80~100W / (m·K). In addition, the specific heat, thermal conductivity, and thermal expansion coefficient of silicon oxynitride are close to those of silicon nitride. The specific heat, thermal conductivity, and thermal expansion coefficient of aluminum oxynitride are close to those of aluminum nitride.

[0033] The first electrode layer 30 is formed on the surface of the first insulating layer 20, and in this embodiment, is the top surface of the first insulating layer 20. The second electrode layer 40 is located below the core substrate 10. The first electrode layer 30 and the second electrode layer 40 are both metal layers. In this embodiment, the second electrode layer 40 is formed on the second surface 12 of the core substrate 10. The first electrode layer 30 and the second electrode layer 40 are both made of three interfacial metal compounds. For example, the first electrode layer 30 and the second electrode layer 40 can be gold (Au) / nickel (Ni) / copper (Cu). For example, the first electrode layer 30 is a copper layer 33, a nickel layer 32, and a gold layer 31 in order from the core substrate 10 to the outside, and the second electrode layer 40 is a copper layer 43, a nickel layer 42, and a gold layer 41 in order from the core substrate 10 to the outside. However, the present invention is not limited thereto. The first electrode layer 30 and the second electrode layer 40 may be made of a material selected from the group consisting of gold (Au) / nickel (Ni) / copper (Cu), gold (Au) / palladium (Pd) / nickel (Ni) / copper (Cu), and gold (Au) / platinum (Pt) / titanium (Ti). However, the present invention is not limited thereto. The first electrode layer 30 and the second electrode layer 40 may be formed by electroplating, sputtering, evaporation, or chemical vapor deposition.

[0034] The solder layer 50 is used to electrically connect to the chip. The solder layer 50 is formed on the top surface of the first electrode layer 30. The solder layer 50 is made of three interfacial metal compounds. For example, the solder layer 50 of this embodiment is gold (Au) / gold tin (AuSn) / platinum (Pt). The solder layer 50 is composed of a platinum layer 53, a gold tin layer 52, and a gold layer 51 in the direction from the core substrate 10 outward. However, the present invention is not limited to this. The solder layer 50 can be a group selected from the following: gold (Au) / gold tin (AuSn) / platinum (Pt) / titanium (Ti), gold (Au) / gold tin (AuSn) / platinum (Pt), and gold (Au) / gold tin (AuSn), but is not limited to this. The solder layer 50 can be formed by electroplating, sputtering, evaporation, or chemical vapor deposition.

[0035] [Second embodiment]

[0036] like Figure 2 As shown, the multi-layer composite heat dissipation substrate of this embodiment includes a core substrate 10 , a first insulating layer 20 , a second insulating layer 21 , a first electrode layer 30 , a second electrode layer 40 , and a solder layer 50 .

[0037] This embodiment is similar to the first embodiment, except that this embodiment further includes a second insulating layer 21 . In this embodiment, the second insulating layer 21 is formed between the second surface 12 of the core substrate 10 and the second electrode layer 40 .

[0038] The second insulating layer 21 is similar to the first insulating layer 20. The second insulating layer 21 can be made by sputtering, electron beam evaporation, chemical vapor deposition, or sol-gel process. The second insulating layer 21 can be composed of nitride, oxide, or oxynitride. Among them, nitride, such as silicon nitride (SiN) or aluminum nitride (AlN); oxide, such as silicon dioxide (SiO2) or aluminum oxide (AlO); oxynitride, such as silicon oxynitride (SiON) or aluminum oxynitride (AlON). This embodiment can further improve the thermal conductivity of the multi-layer composite heat dissipation substrate through the second insulating layer 21.

[0039] [Beneficial Effects of Embodiments]

[0040] The beneficial effect of the present invention lies at least in that the multi-layer composite heat dissipation substrate provided by the present invention can be provided through the technical solution of a core substrate, an insulating layer, an electrode layer, and a solder layer, wherein the insulating layer is provided between the core substrate and the electrode layer, and has higher thermal conductivity than the existing ceramic substrate, thereby improving the heat dissipation effect for high-power chips.

[0041] The contents disclosed above are only feasible embodiments of the present invention and do not limit the scope of the present invention. Therefore, all equivalent changes and modifications made using the contents of the present invention description and drawings are included in the protection scope of the present invention.

Claims

1. A multi-layer composite heat dissipation substrate, characterized in that: include: A core substrate having a first surface and a second surface; a first insulating layer formed on the first surface of the core substrate, wherein the first insulating layer is made of an insulating material selected from the group consisting of: nitride, oxide, and oxynitride; a first electrode layer formed on a top surface of the first insulating layer, the first insulating layer being located between the core substrate and the first electrode layer; a second electrode layer located below the core substrate; and A solder layer is formed on the top surface of the first electrode layer.

2. The multi-layer composite heat dissipation substrate according to claim 1, characterized in that: The core substrate is made of a material selected from the group consisting of conductive silicon carbide, semi-insulating silicon carbide, ceramic, diamond-metal hybrid and diamond.

3. The multi-layer composite heat dissipation substrate according to claim 1, characterized in that: The second electrode layer is formed on the second surface of the core substrate.

4. The multi-layer composite heat dissipation substrate according to claim 1, characterized in that: The first insulating layer is formed by sputtering, electron beam evaporation, chemical vapor deposition or sol-gel method.

5. The multi-layer composite heat dissipation substrate according to claim 1, characterized in that: The invention also includes a second insulating layer formed between the second surface of the core substrate and the second electrode layer, wherein the second insulating layer is made of an insulating material selected from the group consisting of nitride, oxide, and oxynitride.

6. The multi-layer composite heat dissipation substrate according to claim 5, characterized in that: The second insulating layer is formed by sputtering, electron beam evaporation, chemical vapor deposition or sol-gel method.

7. The multi-layer composite heat dissipation substrate according to claim 1 or 5, characterized in that: The nitride is silicon nitride or aluminum nitride, the oxide is silicon dioxide or aluminum oxide, and the oxynitride is silicon oxynitride or aluminum oxynitride.

8. The multi-layer composite heat dissipation substrate according to claim 1, characterized in that: The first electrode layer is made of a group selected from the following: gold / nickel / copper, gold / palladium / nickel / copper, and gold / platinum / titanium, and is made by electroplating, sputtering, evaporation, or chemical vapor deposition.

9. The multi-layer composite heat dissipation substrate according to claim 3 or 5, characterized in that: The second electrode layer is made of a material selected from the group consisting of gold / nickel / copper, gold / palladium / nickel / copper, and gold / platinum / titanium, and is formed by electroplating, sputtering, evaporation, or chemical vapor deposition.

10. The multi-layer composite heat dissipation substrate according to claim 1, characterized in that: The solder layer is selected from the group consisting of gold / gold tin / platinum / titanium, gold / gold tin / platinum, and gold / gold tin, and is made by electroplating, sputtering, evaporation or chemical vapor deposition.

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