Double-sided active metal brazing substrate and manufacturing method thereof

Abstract

The invention discloses a double-sided active metal brazing substrate and a manufacturing method thereof. The double-sided active metal brazing substrate comprises a ceramic substrate layer, a first barrier layer, a second barrier layer, a first active metal layer, a second active metal layer, a first conductive metal layer and a second conductive metal layer. The first active metal layer is arranged on the first surface of the ceramic substrate layer, the first barrier layer surrounds and contacts the first active metal layer, and the first conductive metal layer is arranged on the first active metal layer. The second active metal layer is arranged on the second surface of the ceramic substrate layer, the second barrier layer surrounds and contacts the second active metal layer, and the second conductive metal layer is arranged on the second active metal layer. Through the structural design that the thickness of the barrier layer is smaller than that of the active metal layer, the effect that the solder does not overflow is achieved.

Description

Technical Field

[0001] The present application relates to a double-sided active metal brazing substrate and a manufacturing method thereof, and more particularly to a double-sided active metal brazing substrate with high-precision pattern circuits and a manufacturing method thereof. Background Art

[0002] Driven by growing global awareness of energy conservation and carbon reduction, and driven by national policies, electric vehicles have become a key R&D project for automakers. The recent launch of 800V high-voltage vehicle series by automakers has further driven demand for substrate materials with high performance.

[0003] Under high voltage, high frequency, and high operating temperature operating conditions, ceramic substrates offer higher reliability and heat dissipation capabilities than other substrate materials. Direct-bonding-copper (DBC) ceramic substrates were previously the most widely used. However, these traditional DBC substrates are no longer able to meet the packaging requirements for high temperature, high power, high heat dissipation, and high reliability. Therefore, the mainstream substrate material is gradually shifting from DBC substrates to active metal brazing (AMB) substrates.

[0004] During the manufacturing process of active metal brazing substrates, a layer of solder can be applied to the surface of the ceramic substrate and then copper-clad. Subsequently, two or more etching processes are performed to create patterned circuits on the ceramic substrate. Alternatively, a patterned active metal solder can be directly printed on the surface of the ceramic substrate, copper-clad, and then etched once to create the patterned circuits. Patterned active metal solder printing not only eliminates solder in inactive areas of the pattern, reducing costs, but also eliminates the subsequent cost of secondary solder etching.

[0005] During the high-temperature sintering process, patterned metal solder is prone to flow. If the solder overflows into the non-patterned area, it can cause a short circuit. Finally, a secondary etching process is performed to remove the solder that overflows into the pattern gaps. This not only fails to save etching costs, but also affects the overall pattern accuracy of the circuit, thereby affecting product quality.

[0006] Therefore, how to prevent the solder from overflowing during the sintering process and overcome the above-mentioned defects through improvements in structural design or manufacturing methods has become one of the important issues that this industry wants to solve. Summary of the Invention

[0007] The technical problem to be solved by the present application is to provide a double-sided active metal brazing substrate and a manufacturing method thereof in view of the deficiencies in the prior art.

[0008] In order to solve the above-mentioned technical problems, one of the technical solutions adopted in this application is to provide a double-sided active metal brazing substrate. The double-sided active metal brazing substrate includes a ceramic substrate layer, a first active metal layer, a second active metal layer, a first barrier layer, a second barrier layer, a first conductive metal layer, and a second conductive metal layer. The ceramic substrate layer has a first surface and a second surface. The first active metal layer is arranged on the first surface; the second active metal layer is arranged on the second surface. The first barrier layer surrounds and contacts the first active metal layer, and the thickness of the first barrier layer is less than the thickness of the first active metal layer. The second barrier layer surrounds and contacts the second active metal layer, and the thickness of the second barrier layer is less than the thickness of the second active metal layer. The first conductive metal layer is arranged on the first active metal layer, and the second conductive metal layer is arranged on the second active metal layer.

[0009] Furthermore, the ratio of the thickness of the first barrier layer to the thickness of the first active metal layer is 0.1 to 0.95.

[0010] Furthermore, the material of the first barrier layer includes aluminum oxide, magnesium oxide, zirconium oxide, silicon oxide, aluminum nitride or silicon nitride.

[0011] Furthermore, the thickness of the first barrier layer is 1 micrometer to 5 micrometers.

[0012] Furthermore, the width of the first barrier layer is 0.1 mm to 30 mm.

[0013] Furthermore, the thickness of the first active metal layer is 10 micrometers to 50 micrometers.

[0014] In order to solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a method for manufacturing a double-sided active metal brazing substrate. The method for manufacturing a double-sided active metal brazing substrate includes: performing a patterning process to generate a first barrier layer on a first surface of a ceramic substrate layer, the first barrier layer defines a first patterned area; generating a second barrier layer on a second surface of the ceramic substrate layer, the second barrier layer defines a second patterned area. Subsequently, a first active metal layer is generated in the first patterned area, and a first conductive metal layer is arranged on the first active metal layer; a second active metal layer is generated in the second patterned area, and a second conductive metal layer is arranged on the second active metal layer. Relative to the first surface, the thickness of the first barrier layer is less than the thickness of the first active metal layer; relative to the second surface, the thickness of the second barrier layer is less than the thickness of the second active metal layer. Finally, a brazing process is performed to fix the first active metal layer and the second active metal layer on the ceramic substrate layer.

[0015] Furthermore, the sintering temperature in the brazing process is 800°C to 950°C.

[0016] Furthermore, the sintering pressure in the brazing process is less than 8×10 -5 Thor.

[0017] Furthermore, the tensile strength of the double-sided active metal brazing substrate is greater than 100 Newtons per centimeter.

[0018] One of the beneficial effects of the present application is that the double-sided active metal brazing substrate and its manufacturing method provided in the present application can prevent the solder from overflowing at high temperatures and improve the bonding strength between the ceramic substrate layer and the conductive metal layer through the technical solutions of "setting a barrier layer" and "the thickness of the barrier layer is lower than the thickness of the active metal layer".

[0019] To further understand the features and technical content of this application, please refer to the following detailed description and drawings of this application. However, the drawings provided are only for reference and explanation and are not intended to limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a side view of a double-sided active metal brazing substrate according to one embodiment of the present application.

[0021] Figure 2 Schematic diagram of the steps of disposing a barrier layer on a ceramic substrate layer in the present application.

[0022] Figure 3 Schematic diagram of the steps of disposing an active metal layer on a ceramic substrate layer in the present application.

[0023] Figure 4 Schematic diagram of the steps of disposing a conductive metal layer on the active metal layer in the present application.

[0024] Figure 5 This is a side view of a double-sided active metal brazing substrate according to another embodiment of the present application. DETAILED DESCRIPTION

[0025] The following is an explanation of the implementation methods of the "double-sided active metal brazing substrate and its manufacturing method" disclosed in this application through specific examples. Those skilled in the art can understand the advantages and effects of this application from the content disclosed in this specification. This application 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 deviating from the concept of this application. In addition, the drawings of this application are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following implementation methods will further explain the relevant technical content of this application in detail, but the disclosed content is not intended to limit the scope of protection of this application. In addition, the term "or" used in this article may include any one or more combinations of the associated listed items depending on the actual situation.

[0026] To prevent solder from overflowing from the pattern edges into the non-patterned reserved area during the sintering process, this application first applies a barrier layer to the ceramic substrate layer to define the patterned area, and then applies active metal solder within the patterned area. The barrier layer prevents active metal solder from overflowing during the brazing process, ensuring high-precision circuit patterns on double-sided active metal brazing substrates and eliminating the need for re-etching excess solder.

[0027] The present application further controls the thickness of the barrier layer. Experiments have shown that under high-temperature conditions, the barrier layer material reacts with the active metal solder, negatively impacting the bonding strength between the active metal solder and the subsequently applied conductive metal layer. Therefore, controlling the thickness of the barrier layer allows the present application's double-sided active metal brazing substrate to possess higher tensile strength.

[0028] In this specification, a double-sided active metal brazing substrate refers to a substrate with conductive metal layers on opposite sides. It should be noted that the conductive metal layers on both sides can have the same or different patterning. For example, the conductive metal layer on one side can serve as a circuit layer, while the conductive metal layer on the other side can serve as a heat sink layer. Alternatively, both conductive metal layers can serve as circuit layers. However, this application is not limited to this.

[0029] See also Figure 1 As shown, the double-sided active metal brazing substrate of the present application includes: a ceramic substrate layer 1, a first barrier layer 2, a second barrier layer 2', a first active metal layer 3, a second active metal layer 3', a first conductive metal layer 4 and a first conductive metal layer 4'.

[0030] The first barrier layer 2, the first active metal layer 3 and the first conductive metal layer 4 are arranged on the first surface 11 of the ceramic substrate layer 1, and the second barrier layer 2', the second active metal layer 3' and the second conductive metal layer 4' are arranged on the second surface 11' of the ceramic substrate layer 1. The following will describe the structure of each layer in the double-sided active metal brazing substrate.

[0031] Ceramic substrate layer

[0032] Ceramic substrate layer 1 is a substrate that can support a double-sided printed structure. It can be made of silicon nitride (Si3N4), silicon carbide (SiC), aluminum nitride (AlN), or aluminum oxide (Al2O3). It is preferably a silicon-containing ceramic substrate, more preferably a silicon nitride ceramic substrate. Furthermore, ceramic substrate layer 1 can have a thickness of 0.25 mm to 1 mm, but this application is not limited thereto.

[0033] barrier layer

[0034] The barrier layer is disposed on the ceramic substrate layer 1 . The barrier layer can define a patterned area on the ceramic substrate layer 1 . The patterned area can be designed or adjusted according to the pattern structures of the active metal layer and the conductive metal layer.

[0035] exist Figure 1 In the illustrated structure, first barrier layer 2 is disposed on first surface 11 and defines a patterned region. The extent of this patterned region can be designed or adjusted based on the pattern structures of first active metal layer 3 and first conductive metal layer 4. Similar to first barrier layer 2, second barrier layer 2' is disposed on second surface 11' and defines another patterned region. The extent of this patterned region can be designed or adjusted based on the pattern structures of second active metal layer 3' and second conductive metal layer 4'.

[0036] Since the conductive metal layers on both sides of the ceramic substrate layer may have the same or different patterned patterns, the patterned area defined by the first barrier layer 2 may be the same as or different from the patterned area defined by the second barrier layer 2 ′.

[0037] The barrier layer can prevent the active metal layer from overflowing from the patterned area under high temperature conditions (such as during soldering), thereby producing a double-sided active metal soldering substrate with highly precise pattern circuits.

[0038] To prevent the active metal layer from overflowing the patterned area, the barrier layer is made of a highly heat-resistant material with low compatibility with the active metal layer. Even if molten active metal material were to contact the barrier layer, its strong internal cohesive forces would cause it to converge inward and not exceed the patterned area defined by the barrier layer.

[0039] Specifically, the barrier layer material can be aluminum oxide (Al2O3), magnesium oxide (MgO), zirconium oxide (ZrO2), silicon oxide (SiO2), aluminum nitride (AlN), or silicon nitride (Si3N4). For example, the barrier layer can be composed of particles of the aforementioned high-heat-resistant materials. A barrier layer composed of particles can provide a lower affinity between the barrier layer material and the active metal layer material. For example, the particles can have an average particle size of less than 12 microns. In one exemplary embodiment, the particles have an average particle size of 3 to 12 microns, e.g., a positive integer between 3 and 12 microns.

[0040] Furthermore, to achieve a good barrier effect, the width of the barrier layer can be further controlled. A wider barrier layer makes it more difficult for the active metal layer material to cross the barrier layer and extend beyond the patterned area. In one exemplary embodiment, the width of the barrier layer is 0.1 mm to 30 mm. For example, the width of the barrier layer can be a positive integer between 0.1 mm and 30 mm.

[0041] Regarding the thickness of the barrier layer, experiments have found that under high temperature conditions, the material of the barrier layer will react with the material of the active metal layer at the contact surface, or may diffuse to the upper surface of the active metal layer.

[0042] Specifically, the original purpose of the active metal layer is to bond with the conductive metal layer. However, the active metal layer reacts with the barrier layer or diffuses to the interface between the two layers, weakening the bonding strength between them. Therefore, the present invention further controls the thickness of the barrier layer to be lower than that of the active metal layer, thereby preventing the active metal layer from overflowing the patterned area without reducing the bonding strength of the conductive metal layer.

[0043] To facilitate the definition of the thickness of each layer, in this specification, the thickness of the first barrier layer 2 and the thickness of the first active metal layer 3 refer to the direction perpendicular to the first surface 11. The thickness of the second barrier layer 2' and the thickness of the second active metal layer 3' refer to the direction perpendicular to the second surface 11'.

[0044] In addition, by controlling the thickness ratio of the barrier layer to the active metal layer, the present invention achieves excellent pattern circuit accuracy in a double-sided active metal brazing substrate without negatively impacting the bonding strength between the active metal layer and the conductive metal layer. Specifically, the thickness ratio of the first barrier layer 2 to the first active metal layer 3 is 0.1 to 0.95. For example, the thickness ratio of the first barrier layer 2 to the first active metal layer 3 can be 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.8, 0.85, or 0.90. The thickness ratio of the second barrier layer 2' to the second active metal layer 3' is 0.1 to 0.95. For example, the thickness ratio of the second barrier layer 2' to the second active metal layer 3' can be 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.8, 0.85 or 0.90.

[0045] In an exemplary embodiment, the thickness of the first barrier layer 2 is 1 micrometer to 5 micrometers, and the thickness of the second barrier layer 2 ′ is 1 micrometer to 5 micrometers.

[0046] To achieve the above-mentioned barrier layer thickness design, the barrier layer can be provided on the ceramic substrate layer 1 by screen printing (or stencil printing). However, the method of providing the barrier layer is not limited to this, and any method can be applied in this application as long as the thickness of the barrier layer is thinner than that of the active metal layer.

[0047] Active metal layer

[0048] The active metal layer is disposed in the patterned area defined by the barrier layer, and the active metal layer is disposed between the ceramic substrate layer 1 and the conductive metal layer to fix the conductive metal layer on the ceramic substrate layer 1 .

[0049] exist Figure 1 In the illustrated structure, the first active metal layer 3 is disposed within the patterned region defined by the first barrier layer 2. That is, the first barrier layer 2 surrounds the first active metal layer 3. To more precisely control the shape of the circuit layer, the first barrier layer 2 may contact the side of the first active metal layer 3 to prevent the active metal solder paste from overflowing the patterned region in a high-temperature environment.

[0050] Similar to the first active metal layer 3, the second active metal layer 3' is disposed within the patterned area defined by the second barrier layer 2'. In other words, the second barrier layer 2' surrounds the second active metal layer 3'. Furthermore, the second barrier layer 2' may contact the side surfaces of the second active metal layer 3' to prevent the active metal solder paste from overflowing the patterned area in high-temperature environments.

[0051] The active metal layer is formed using an active metal solder paste. This paste consists of an active metal solder and an organic dispersion medium. Under high temperature conditions, the active metal solder alloys with the ceramic substrate layer and the conductive metal layer, achieving a bond.

[0052] The active metal solder includes silver (Ag), copper (Cu), and an active metal. Specifically, the active metal can be selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), and hafnium (Hf). In a preferred embodiment, the active metal solder includes silver (Ag), copper (Cu), and titanium (Ti). Under high temperature conditions (the brazing process), some of the metal can diffuse into the ceramic substrate to form metal-silicon compounds or metal-nitride compounds. Some of the metal can also diffuse into the conductive metal layer to form an alloy, enhancing the bonding effect.

[0053] As described above, by coating the active metal layer in the patterned area surrounded by the barrier layer and controlling the thickness of the active metal layer to be higher than that of the barrier layer, the double-sided active metal brazing substrate of the present application can have a higher tensile strength.

[0054] As the thickness of the active metal layer increases, the bonding strength between the ceramic substrate layer and the conductive metal layer also improves. However, when the active metal layer is too thick, the material cost of the active metal layer is too high, making it unsuitable for mass production. Therefore, the thickness of the active metal layer 2 is greater than or equal to 6 microns. If the thickness of the active metal layer is not less than that of the barrier layer and does not cause process cost issues, the thickness of the active metal layer can be 10 microns to 50 microns. For example, the thickness of the active metal layer 2 can be a positive integer between 10 microns and 50 microns.

[0055] Conductive metal layer

[0056] The conductive metal layer is disposed on the active metal layer. Since the bonding force between the conductive metal layer and the ceramic substrate layer 1 is relatively weak, the conductive metal layer needs to be disposed on the ceramic substrate layer via the active metal layer.

[0057] Through different structural designs, the conductive metal layer can be used as the circuit layer or the heat dissipation layer of the active metal brazing substrate. When used as the circuit layer, the pattern accuracy of the conductive metal layer will have a significant impact on the quality of the double-sided active metal brazing substrate.

[0058] exist Figure 1 In the illustrated structure, a first conductive metal layer 4 is secured to the first surface 11 of the ceramic substrate layer 1 via a first active metal layer 3. The pattern structure of the first conductive metal layer 4 corresponds to the pattern structure of the first active metal layer 3. Similar to the first conductive metal layer 4, a first conductive metal layer 4' is disposed on the second surface 11' of the ceramic substrate layer 1 via a second active metal layer 3'. The pattern structure of the second conductive metal layer 4' corresponds to the pattern structure of the second active metal layer 3'.

[0059] Specifically, the conductive metal layer can be a metal copper foil, a metal aluminum foil or a copper-aluminum alloy foil. In a preferred embodiment, the conductive metal layer is preferably a metal copper foil.

[0060] Due to the excellent bonding strength between the ceramic substrate layer and the conductive metal layer of the present application, a thicker conductive metal layer can be welded, and its thickness can be 0.2 mm to 1.5 mm, for example: 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm or 1.4 mm.

[0061] Method for manufacturing double-sided active metal brazing substrate

[0062] The manufacturing method of the double-sided active metal brazing substrate of the present application is to sequentially set a barrier layer (patterning process), an active metal layer (coating process, drying process) and a conductive metal layer on a ceramic substrate layer, and then perform a brazing process to complete the double-sided active metal brazing substrate.

[0063] As previously described, a barrier layer, an active metal layer, and a conductive metal layer are formed on opposite sides of the ceramic substrate layer. In practice, the barrier layer can be formed on both the first and second surfaces of the ceramic substrate layer, followed by the active metal layer and the conductive metal layer, respectively, as needed. Alternatively, the barrier layer, active metal layer, and conductive metal layer can be formed on the first surface of the ceramic substrate layer, followed by the barrier layer, active metal layer, and conductive metal layer, respectively, on the second surface of the ceramic substrate layer.

[0064] In step S1, a patterning process is performed to generate a barrier layer on the ceramic substrate layer. The structure of the barrier layer is designed to define a patterned area, such as Figure 2 shown.

[0065] Specifically, a first barrier layer is formed on the first surface of the ceramic substrate layer, the first barrier layer defining a first patterned region. A second barrier layer is formed on the second surface of the ceramic substrate layer, the second barrier layer defining a second patterned region. For ease of explanation, the following description of the method for manufacturing a double-sided active metal brazing substrate will be generally referred to, but this application is not limited thereto.

[0066] In the patterning process, the barrier layer may be formed by screen printing, but the present application is not limited thereto.

[0067] In step S2, a preparation process is performed to prepare an active metal solder paste. The active metal solder paste is used to form the aforementioned active metal layer, and the active metal solder paste contains the aforementioned active metal solder and an organic dispersion medium.

[0068] The active metal solder comprises the aforementioned silver, copper, and an active metal. In some embodiments, the active metal solder is a combination of silver powder, copper powder, and titanium powder. In other embodiments, the active metal solder may be a combination of active metal powder and at least one of silver powder, copper powder, and silver-copper alloy powder.

[0069] Taking the total weight of the active metal solder as 100 weight percent, the content of metallic silver in the active metal solder is 10 weight percent to 60 weight percent, the content of metallic copper is 30 weight percent to 80 weight percent, and the content of the active metal is 1 weight percent to 10 weight percent.

[0070] The organic dispersion medium can help disperse the active metal solder and help the active metal solder paste solidify to form an active metal layer. Specifically, the organic dispersion medium includes a paste-forming agent, an organic solvent, and a thixotropic agent. Taking the total weight of the organic dispersion medium as 100 weight percent, the content of the paste-forming agent is 20 weight percent to 30 weight percent, the content of the organic solvent is 50 weight percent to 70 weight percent, and the content of the thixotropic agent is 1 weight percent to 5 weight percent. However, the present application is not limited thereto, as long as the active solder powder and the organic component can be mixed into an active solder paste with a viscosity suitable for coating on the ceramic substrate layer to facilitate the formation of the active metal layer.

[0071] In step S3, a coating process is performed to coat the active metal solder paste on the patterned area. In the coating process, the active metal solder paste can be coated on the patterned area by screen printing.

[0072] In step S4, a drying process is performed to form an active metal layer from the active metal solder paste. In the drying process, the active metal solder paste is dried at a temperature of 90°C to 110°C for 5 to 15 minutes to volatilize most of the organic solvent in the active metal solder paste, thereby forming an active metal layer. Figure 3 shown.

[0073] In step S5, Figure 4 As shown, a conductive metal layer is disposed on the active metal layer.

[0074] In step S6 , a brazing process is performed to connect the conductive metal layer to the active metal layer and fix it to the ceramic substrate layer.

[0075] During the brazing process, the vacuum degree can be less than or equal to 8×10 -5 A first stage heat treatment process and a second stage heat treatment process are carried out in sequence under Torr. The temperature condition of the first stage heat treatment process is 800°C to 890°C, and the temperature condition of the second stage heat treatment process is 900°C to 1100°C (i.e., the brazing temperature range). The temperature of the second stage heat treatment process is higher than that of the first stage heat treatment process and is maintained at the highest temperature for 30 minutes.

[0076] In a preferred embodiment, the heating rate of the heat treatment process may be, for example, 5° C. / min to 30° C. / min, and the cooling rate after the brazing process may be, for example, 2° C. / min to 30° C. / min.

[0077] After the conductive metal layer is provided, an etching process may be selectively performed to remove the conductive metal layer outside the patterned area, thereby achieving patterning and generating a final product, such as Figure 1 shown.

[0078] In other embodiments, during the etching process, the barrier layer may also be removed along with the conductive metal layer outside the patterned area to obtain a Figure 5 Double-sided active metal brazing substrate shown. This step is optional and the barrier layer can be left unremoved.

[0079] In order to verify that the double-sided active metal brazing substrate of the present application has a highly precise pattern circuit, double-sided active metal brazing substrates of Examples 1 to 3 and single-sided active metal brazing substrates of Comparative Examples 1 to 3 were prepared according to the above steps S1 to S6.

[0080] Examples 1 to 3

[0081] In the double-sided active metal brazing substrates of Examples 1 to 3, the ceramic substrate layer is a silicon nitride ceramic substrate. The first and second barrier layers are made of alumina. The first and second active metal layers are made of silver, copper, and titanium. Based on the total weight of the active metal brazing material as 100 weight percent, the silver content is 70 weight percent, the copper content is 25 weight percent, and the titanium content is 5 weight percent. The first and second conductive metal layers are copper foil.

[0082] The differences between Examples 1 to 3 are that the thickness of the active metal layer is different, and the thickness ratio of the barrier layer to the active metal layer is also different.

[0083] During the brazing process, the vacuum degree is less than or equal to 8×10 -5 The temperature of the first stage heat treatment process is 855℃, and the temperature condition of the second stage heat treatment process is 915℃, and it is maintained at the highest temperature for 30 minutes.

[0084] After the active metal brazing substrates were prepared, the results of Examples 1 to 3 regarding the thickness of the barrier layer, the thickness of the active metal layer, the printing position, and whether the solder diffused after brazing are listed in Table 1. Furthermore, the tensile strength of the active metal brazing substrates was measured at 25°C according to JIS-C-6481, and the results are also listed in Table 1.

[0085] Comparative Examples 1 to 3

[0086] The single-sided active metal brazing substrates in Comparative Examples 1 to 3 were manufactured using a similar method to the double-sided active metal brazing substrate in Example 1. The differences between these two methods are that the layer was only provided on one side of the ceramic substrate. Furthermore, the thickness of the barrier layer in Comparative Examples 1 and 2 was greater than that of the active metal layer, while no barrier layer was provided in Comparative Example 3.

[0087] After the active metal brazing substrates were prepared, the results of the barrier layer thickness, active metal layer thickness, printing position, and whether the solder diffused after brazing in Comparative Examples 1 to 3 are listed in Table 1. Furthermore, the tensile strength of the active metal brazing substrates was measured at 25°C according to JIS-C-6481, and the results are also listed in Table 1.

[0088] Table 1

[0089]

[0090] The results in Table 1 indicate that the barrier layer prevents solder diffusion and maintains the fineness of the active metal brazing substrate's circuit patterns. Furthermore, when the barrier layer's thickness is controlled to be lower than that of the active metal layer, the active metal brazing substrate exhibits higher tensile strength.

[0091] Therefore, the double-sided active metal brazing substrate of this application can prevent the active metal layer from overflowing the patterned area without reducing the bonding strength of the conductive metal layer (tensile strength greater than 100 Newtons / cm). The double-sided printing structure of this application does not affect the overall structural strength, providing greater functionality than single-sided printing structures while maintaining a tensile strength greater than 100 Newtons / cm.

[0092] Advantageous Effects of the Embodiments

[0093] One of the beneficial effects of the present application is that the double-sided active metal brazing substrate and its manufacturing method provided in the present application can prevent the solder from overflowing at high temperatures and improve the bonding strength between the ceramic substrate layer and the conductive metal layer through the technical solutions of "setting a barrier layer" and "the thickness of the barrier layer is lower than the thickness of the active metal layer".

[0094] The contents disclosed above are only preferred feasible embodiments of the present application and do not limit the scope of protection of the claims of the present application. Therefore, all equivalent technical changes made using the contents of the present application specification and drawings are included in the scope of protection of the claims of the present application.

Claims

1. A double-sided active metal brazing substrate, characterized in that: The double-sided active metal brazing substrate comprises: a ceramic substrate layer having a first surface and a second surface; a first active metal layer disposed on the first surface; a second active metal layer disposed on the second surface; a first barrier layer surrounding and contacting the first active metal layer; the thickness of the first barrier layer is less than the thickness of the first active metal layer; a second barrier layer surrounding and contacting the second active metal layer; the second barrier layer having a thickness less than that of the second active metal layer; a first conductive metal layer disposed on the first active metal layer; and A second conductive metal layer is disposed on the second active metal layer.

2. The double-sided active metal brazing substrate according to claim 1, characterized in that: The thickness ratio of the first barrier layer to the first active metal layer is 0.1 to 0.

95.

3. The double-sided active metal brazing substrate according to claim 1, characterized in that: The material of the first barrier layer includes aluminum oxide, magnesium oxide, zirconium oxide, silicon oxide, aluminum nitride or silicon nitride.

4. The double-sided active metal brazing substrate according to claim 1, characterized in that: The thickness of the first barrier layer is 1 micrometer to 5 micrometers.

5. The double-sided active metal brazing substrate according to claim 1, characterized in that: The width of the first barrier layer is 0.1 mm to 30 mm.

6. The double-sided active metal brazing substrate according to claim 1, characterized in that: The thickness of the first active metal layer is 10 micrometers to 50 micrometers.

7. A method for manufacturing a double-sided active metal brazing substrate, characterized in that: It includes: Performing a patterning process to form a first barrier layer on a first surface of a ceramic substrate layer and a second barrier layer on a second surface of the ceramic substrate layer; wherein the first barrier layer defines a first patterned area and the second barrier layer defines a second patterned area; forming a first active metal layer in the first patterned area and forming a second active metal layer in the second patterned area; Disposing a first conductive metal layer on the first active metal layer, and disposing a second conductive metal layer on the second active metal layer; and performing a brazing process to fix the first conductive metal layer to the ceramic substrate layer and to fix the second active metal layer to the ceramic substrate layer; The thickness of the first barrier layer is smaller than that of the first active metal layer, and the thickness of the second barrier layer is smaller than that of the second active metal layer.

8. The manufacturing method according to claim 7, characterized in that The sintering temperature in the brazing process is 800°C to 950°C.

9. The manufacturing method according to claim 7, characterized in that: The sintering pressure in the brazing process is less than 8×10 -5 Thor.

10. The manufacturing method according to claim 7, characterized in that: The tensile strength of the double-sided active metal brazing substrate is greater than 100 Newtons per centimeter.

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