CN115703177A - A kind of Cu-based alloy brazing filler metal, silicon nitride ceramic copper-clad substrate adopting the brazing filler metal and manufacturing method thereof - Google Patents

Abstract

The invention relates to a Cu-based alloy solder, a silicon nitride ceramic copper-clad substrate using the solder and a manufacturing method thereof. The solder is an amorphous alloy, the expression is Cu _a Ti _b Zr _c M _d Al _e Ag _f Sn _g , M is at least one of Hf, Nb, Ta, Mo, Ni, Cr, a, b, c, d, e, f, g respectively represent the atomic percentage, 40≤a≤65, 5≤b≤15, 5≤c≤15, 0≤d≤10, 1≤e≤15, 0≤f≤5, 10≤g≤30, a+b+c+d+e+f+g=100; the silicon nitride ceramic copper-clad substrate includes a silicon nitride ceramic substrate, copper foil, and an interlayer between the two and connecting them The connecting layer is formed by brazing with the above-mentioned brazing filler metal. After brazing with the above brazing material, the bonding strength between the silicon nitride ceramic substrate and copper is high, the production efficiency is high, and the cost is low.

Description

A kind of Cu-based alloy brazing filler metal, silicon nitride ceramic copper-clad substrate adopting the brazing filler metal and its Manufacturing method

technical field

The invention belongs to the technical field of electronic packaging, and in particular relates to a Cu-based alloy solder, a silicon nitride ceramic copper-clad substrate using the solder and a manufacturing method thereof, and is particularly suitable for manufacturing a copper-clad ceramic substrate of a high-power semiconductor device.

Background technique

Insulated gate bipolar transistor (IGBT) is the most important high-power device in the field of power electronics. It has outstanding advantages such as high operating frequency, high withstand voltage and large operating current. AC/DC conversion and frequency conversion control for locomotives and energy storage power stations, high-voltage and high-current occasions in the industrial field. For high-power IGBT modules, in addition to chip technology, packaging technology is also very critical. Selecting suitable packaging materials and processes, improving the heat dissipation capability and reliability of devices are the key issues that must be solved.

Ceramic substrates are widely used in the packaging of high-power electronic devices due to their high insulation, high thermal conductivity, heat resistance, and low expansion. For high-power electronic devices packaged with ceramic substrates, the heat generated by them can be dissipated through the high thermal conductivity ceramic copper clad laminates to the shell, and due to the high thermal conductivity of oxygen-free copper, the thermal conductivity of ceramic copper clad laminates is mainly determined by ceramics. The thermal conductivity of the substrate material is determined. At present, there are mainly three kinds of ceramics as the material of the ceramic copper clad laminate substrate, which are alumina ceramic substrate, aluminum nitride ceramic substrate and silicon nitride ceramic substrate. Among them, silicon nitride (Si ₃ N ₄ ) ceramics has the advantages of good thermal conductivity, high strength and fracture toughness, and excellent thermal fatigue resistance, and is a ceramic substrate material with good development prospects.

Copper clad ceramic substrate is a composite cermet substrate formed by directly bonding oxygen-free copper with high conductivity to the surface of the ceramic substrate at high temperature. It has both high thermal conductivity, high electrical insulation, high mechanical strength, and Low expansion and other characteristics, but also high conductivity and excellent welding performance of oxygen-free copper, is the key material for power module packaging and connection chip and heat dissipation substrate in the field of power electronics.

There are three methods for copper cladding on ceramic substrates. The first is the copper plating method on the ceramic surface. In this method, a metal transition layer is first attached on the ceramic substrate. The transition layer can deposit a metal seed layer on the surface of the ceramic substrate by vacuum sputtering, for example: Ti/Cu layer , can also use printing technology to print metal paste on the ceramic substrate, such as: tungsten molybdenum or molybdenum manganese metallization paste, after high temperature sintering, it will be closely combined with the ceramic material, and finally plated on the transition layer by electroplating/electroless plating copper to form a ceramic copper clad substrate. The main disadvantage of this method is that the bonding strength between the electroplated copper layer and the ceramic substrate is low, which affects the reliability of the ceramic copper clad laminate; in addition, the electroplating production speed is low, and the thickness of the electroplated deposited copper layer is limited, which makes it difficult to meet the packaging requirements of high-current power devices. And the pollution of electroplating waste liquid is big. The second is the method of direct copper cladding on ceramics. This method is to heat at a high temperature of about 1063 ° C in oxygen-containing nitrogen, and directly weld a layer of copper foil on the surface of alumina or aluminum nitride ceramics. The basic principle is to use the copper-oxygen eutectic liquid phase formed by copper and oxygen at high temperature and low oxygen content to wet the two contacting material surfaces, that is, the surface of copper foil and the surface of ceramics, and at the same time react with alumina to achieve Strong bond between copper foil and ceramic. The disadvantage of this method is that the process is difficult and the yield is low, and it is only suitable for copper cladding on the surface of aluminum-containing alumina and aluminum nitride ceramics. The third is the active metal welding copper clad method, which uses a small amount of active elements contained in the solder, such as Ti and Zr, to react with the ceramic to form a reaction layer that can be wetted by the liquid solder, thereby realizing the bonding between the ceramic and the metal. A method of bonding. This method was originally used for the welding of alumina ceramics and metals. The commonly used solders are Ti-Ag-Cu and Zr-Ag-Cu, etc., and then developed to the active welding of aluminum nitride. The active metal soldering substrate is bonded by the chemical reaction between the ceramic and the active metal solder paste at high temperature, so its bonding strength is higher and the reliability is better. However, due to the high cost of this method and the lack of suitable solder, the solder has a great influence on the reliability of soldering.

Contents of the invention

The purpose of the present invention is to provide a Cu-based alloy solder, a silicon nitride ceramic copper-clad substrate using the solder and a manufacturing method thereof, so as to at least overcome the low bonding strength of the existing ceramic substrate copper clad, the narrow process window, the production One of technical problems such as low efficiency and high production cost.

To achieve the above object, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a Cu-based alloy solder, which is a Cu-based amorphous alloy with a chemical composition of Cu _a Ti _b Zr _c M _d Al _e Ag _f Sn _g , wherein M is Hf, Nb, One or more of Ta, Mo, Ni, Cr, a, b, c, d, e, f, g respectively represent the atomic percentage of each element, 40≤a≤65, 5≤b≤15, 5≤ c≤15, 0≤d≤10, 1≤e≤15, 0≤f≤5, 10≤g≤30, a+b+c+d+e+f+g=100.

Amorphous alloys are usually eutectic components with a low melting point, and the composition of amorphous alloys is not restricted by the phase diagram and can be adjusted arbitrarily. According to the common characteristics of amorphous alloys, combined with the technical requirements of copper coating on silicon nitride ceramic substrates, and aiming at the technical problems existing in the current copper coating of silicon nitride ceramics, the present invention proposes a Cu-based amorphous alloy, and in the alloy Adding Zr, Ti, Hf, Nb, Ta, Mo, Ni, Cr and other elements is beneficial to the combination with the silicon nitride ceramic substrate. At the same time, in order to reduce the melting point of the alloy, low melting point alloys such as Al, Sn and Ag are added to the alloy composition . In the technical scheme proposed by the invention, the alloy components adopt all metal elements without containing metalloid elements and nonmetal elements. The reasons for the selection of the above components are as follows:

Cu is used as the matrix component of the solder, and it is added for better infiltration with the copper plate during the brazing process. If the content is too high, it is not conducive to the formation of amorphous due to the large nucleation of Cu during the cooling process of preparing the amorphous strip. If the alloy thin strip in the state is too low, the amorphous thin strip in the prepared state will be used as the solder, and the melting point will be too high, even close to or higher than the melting point of Cu. Among the brazing filler metals provided by the present invention, the atomic percentage range is 40≤a≤65, which is more suitable;

As an active element, Ti is added to increase the bonding force between the solder and the ceramic matrix. Its atomic percentage range is 5≤b≤15. If the atomic percentage exceeds 15, the melting point of the solder will increase rapidly, resulting in The melting point is higher than that of Cu and cannot be used; if the atomic percentage is lower than 5, the bonding force between the solder and the silicon nitride ceramic substrate will be low;

As an amorphous forming element, Zr is added to increase the amorphous forming ability of the solder. Its atomic percentage range is 5≤b≤15, which is more suitable. If the atomic percentage exceeds 15, the melting point of the solder will increase rapidly, resulting in The melting point of Cu is higher than the melting point of Cu and cannot be used; if the atomic percentage is lower than 5, the amorphous formation ability of the solder is low, and it is difficult to prepare amorphous alloy thin strips;

M, as an addable transition metal element, can be selected from at least one of Hf, Nb, Ta, Mo, Ni, Cr, and it is added in order to increase the amorphous forming ability of the solder;

Al is not only an active element, but also an adjusting element for the melting point of the solder. Its atomic percentage range is 1≤b≤15. Low soldering temperature affects the bonding force between other active elements and the ceramic substrate; if the atomic percentage is lower than 1, it affects the bonding force between the solder and the ceramic substrate;

As an active element, Ag is added to increase the bonding force between the solder and the ceramic matrix. Its atomic percentage range is 0≤b≤5. During the process, the solder is difficult to remove, which is not conducive to subsequent use; if this element is not added, the bonding force between the solder and the ceramic substrate will be affected during the brazing process;

As a low melting point element, Sn is added to adjust the melting point of the solder, and its atomic percentage range is 10≤b≤30. If the atomic percentage exceeds 30, it will affect the addition of other essential elements; if the atomic percentage is lower than 10 , then the melting point of the brazing filler metal is higher than that of Cu, so it cannot be used.

The above-mentioned Cu-based alloy solder has a chemical composition composed of metal elements, and the sum of other impurity elements does not exceed 1 atomic percent at most.

The above-mentioned Cu-based alloy solder, as a preferred embodiment, a+g≥65, 1≤d≤6, f≤0.5. In this way, an amorphous strip with a good plate shape can be prepared, and its surface quality and tolerance size can meet the needs of brazing. Cu and Sn as the base material, a+g≥65, can ensure that the solder has a suitable melting point, the addition of M element and in the range of 1≤d≤6, can ensure the formation of amorphous, a small amount of addition of Ag (f≤0.5) , can ensure the activity of solder and silicon nitride substrate.

The above-mentioned Cu-based alloy solder, as a preferred embodiment, a+g≥70, 1≤d≤6, 5≤e≤10, f≤0.5. In this way, an amorphous strip with a good plate shape can be prepared, and its surface quality and tolerance size can meet the needs of brazing. Cu and Sn are used as the matrix material, a+g≥70, which can ensure that the solder has a suitable melting point, and the addition of M in the range of 1≤d≤6 ensures that amorphous can be formed, and the addition of Al is limited to 5≤e≤ 10. The melting point of the solder can be better adjusted, and the activity of the solder and the silicon nitride substrate can also be ensured. A small amount of Ag (f≤0.5) can further enhance the activity of the silicon nitride substrate.

As a preferred embodiment of the above Cu-based alloy solder, the solder is an amorphous alloy thin strip or an amorphous alloy powder.

The above-mentioned Cu-based alloy solder, as a preferred embodiment, the solder is prepared by rapid solidification technology, the geometric shape of the solder in the prepared state is a thin strip material, and its thickness is 10-30 μm (such as 12 μm, 15 μm, 20 μm, 25 μm, 28 μm, etc.), more preferably the thickness is 15-20 μm (such as 15.5 μm, 16 μm, 17 μm, 18 μm, 19 μm, 19.5 μm, etc.).

The above-mentioned Cu-based alloy solder, as a preferred embodiment, is prepared by rapid solidification technology, and the width of the solder in the prepared state is 10-200mm (such as 20mm, 30mm, 50mm, 75mm, 100mm, 120mm, 150mm, 180mm, 190mm etc.), the more preferred width is 50-100mm (such as 55mm, 60mm, 70mm, 80mm, 90mm, 95mm, etc.).

The above-mentioned Cu-based alloy solder is especially suitable as a connection layer material, placed between the silicon nitride ceramic substrate and the copper conductive layer, and a reliable connection between the silicon nitride ceramic substrate and the copper conductive layer is realized through a brazing process.

In the second aspect, the present invention also provides a method for manufacturing the above-mentioned Cu-based alloy solder, which is prepared by rapid solidification technology, and can be prepared under vacuum conditions or under an argon protective atmosphere. Preferably, the smelting of raw materials adopts the magnetic levitation smelting method, and if induction smelting is adopted, a calcium oxide crucible must be used.

The manufacturing method of above-mentioned Cu-based alloy brazing filler metal, as a kind of preferred embodiment, comprises:

Firstly, the raw material is melted, and the maximum temperature during the melting process is 1550--1750°C (such as 1560°C, 1580°C, 1600°C, 1650°C, 1680°C, 1700°C, 1720°C, 1740°C, etc.), after full alloying, Cool down to 1120-1350°C (such as 1150°C, 1180°C, 1200°C, 1250°C, 1280°C, 1300°C, 1320°C, 1335°C, etc.), and cast into alloy rods;

Then, remelting the alloy rod, when the temperature of the alloy melt reaches 1120-1380°C (such as 1130°C, 1150°C, 1180°C, 1200°C, 1250°C, 1300°C, 1330°C, 1350°C, etc.), Using a pressure of 0.30-0.50MPa (such as 0.32MPa, 0.35MPa, 0.40MPa, 0.45MPa, 0.48MPa, etc.), the alloy melt is spray-cast at a linear speed of 18-35m/s (such as 20m/s, 22m/s s, 25m/s, 28m/s, 30m/s, 32m/s, 34m/s, etc.) on cooling rolls to obtain alloy thin strips.

According to the alloy composition ratio proposed by the present invention, the strip is prepared by rapid solidification technology, that is, the molten alloy is cast on a high-speed rotating cooling roller through a nozzle, and the thickness is 10-30 microns in one step, and the width can reach about 200 mm. The thin strip of amorphous alloy with a length of several thousand meters has the advantages of simple production process and low material cost.

In the third aspect, the present invention also provides a silicon nitride ceramic copper-clad substrate, including a silicon nitride ceramic substrate, a copper foil, and a connecting layer located between the silicon nitride ceramic substrate and the copper foil and connecting the two , the connection layer is formed by brazing with the above-mentioned Cu-based alloy solder.

In the above-mentioned silicon nitride ceramic copper-clad substrate, generally speaking, the thickness of the connection layer is slightly thinner than that of the amorphous solder, and at the connection between the connection layer and the copper foil, the solder and the Component diffusion occurs between the copper foils to form a diffusion layer; between the connection layer and the silicon nitride ceramic substrate, the active elements of the solder will diffuse into the ceramic substrate; and the rest of the solder solidifies to form an alloy.

In the above-mentioned silicon nitride ceramic copper-clad substrate, as a preferred embodiment, the thickness of the silicon nitride ceramic substrate is 0.2-0.7 mm, and the thickness of the copper foil is 0.3-1.0 mm. Different semiconductor packaging devices have different requirements for the thickness of the silicon nitride ceramic substrate and copper foil, which can be determined according to the requirements of the packaging device in practice.

In the fourth aspect, the present invention also provides a method for manufacturing the above-mentioned silicon nitride ceramic copper-clad substrate, including:

Stack in sequence in the order of silicon nitride ceramic substrate, solder and copper foil;

Place the stacked three materials in the fixture, apply pressure evenly on the stacked copper foil, and then send it into the furnace for brazing treatment, and then cool with the furnace to obtain a silicon nitride copper-clad substrate.

As a preferred embodiment of the method for manufacturing the above-mentioned silicon nitride ceramic copper-clad substrate, the pressure application process is to add 1.0*10 ⁴ Pa-3.0*10 ⁵ Pa (such as 5.0*10 ⁴ Pa, 1.0*10 ⁵ Pa , 1.5*10 ⁵ Pa, 2.0*10 ⁵ Pa, 2.5*10 ⁵ Pa, 2.8*10 ⁵ Pa, etc.).

As a preferred embodiment of the method for preparing the above-mentioned silicon nitride ceramic copper-clad substrate, the brazing treatment includes: 30°C/min, 35°C/min, 40°C/min, 45°C/min, etc.), when the temperature reaches 1020-1060°C (such as 1025°C, 1030°C, 1035°C, 1040°C, 1045°C, 1050°C, 1055°C, etc.), keep warm for 10-60min (such as 15min, 20min, 30min, 40min, 50min, 55min, etc.).

The amorphous alloy thin strip brazing material proposed by the present invention is used as the connection layer material of the copper-clad silicon nitride ceramic substrate. The last three materials are placed in the fixture, and uniform pressure is applied on the stacked copper foil, and then the whole is placed in a vacuum brazing furnace, heated to the liquidus temperature of the amorphous alloy thin strip for brazing . During the brazing process, one side of the connection layer material is infiltrated and connected with the silicon nitride ceramic substrate, and the other side is infiltrated and connected with the copper foil. After cooling, a silicon nitride copper-clad substrate is formed. After brazing, the bonding strength between the ceramic substrate and copper is high. .

Compared with prior art, the beneficial effect of the present invention is:

1) The Cu-based alloy solder proposed by the present invention has a melting point lower than and close to that of copper, and is easy to carry out vacuum brazing, while the alloy contains active metal elements that are easy to combine with silicon nitride ceramic substrates, such as: Zr, Ti, Nb, etc., have high bonding strength between ceramic substrate and copper after brazing, especially suitable for the manufacture of silicon nitride ceramic copper-clad substrate;

2) The Cu-based alloy brazing filler metal proposed by the present invention has a stable preparation process. During use, brazing is carried out at the liquidus temperature of the connecting layer material, and the process window is stable;

3) The method for preparing and using the Cu-based alloy brazing filler metal proposed by the present invention has a mature strip brazing filler metal preparation process, a mature strip brazing technique, and high production efficiency;

4) The connection layer material for the silicon nitride ceramic copper-clad substrate proposed by the present invention and its preparation and use method, the production of the connection layer material adopts rapid solidification technology, and the production speed of the thin strip can reach 30m/s; the thin strip When in use, it is placed between the silicon nitride ceramic substrate and copper, and after multi-layer stacking can be realized, it can be welded in batches in a vacuum brazing furnace, and the production cost is low.

Description of drawings

Fig. 1 is the XRD spectrum of the Cu ₆₀ Ti ₁₀ Zr ₅ Ni ₃ Al _9.5 Ag _0.5 Sn ₁₂ (at.%) alloy proposed in Example 1 of the present invention;

Fig. 2 is an XRD spectrum of the Cu ₅₂ Ti ₈ Zr ₇ Nb ₂ Al _12.5 Ag _0.5 Sn ₁₈ (at.%) alloy proposed in Example 2 of the present invention.

Detailed ways

The content of the present invention will be further described in detail below through the embodiments in conjunction with the accompanying drawings, and the scope of protection of the present invention includes but is not limited to the following embodiments.

If the specific experimental steps or conditions are not indicated in the examples, it can be carried out according to the operation or conditions of the conventional steps described in the literature in this field. All reagents and raw materials used in the examples are commercially available products.

Example 1

The brazing filler metal for silicon nitride ceramic copper-clad substrate proposed in this example and its preparation and use method are formulated according to the material composition Cu ₆₀ Ti ₁₀ Zr ₅ Ni ₃ Al _9.5 Ag _0.5 Sn ₁₂ (at.%), the total The weight is 10 kg, and it is melted in a vacuum induction furnace. The highest temperature during the melting process of the alloy is 1720°C. After the alloy is fully alloyed, the temperature is lowered to 1180°C, and cast into an alloy rod with a diameter of 30mm. In the belted quartz tube, use an induction coil to remelt. When the temperature of the alloy melt reaches 1160°C, use a pressure of 0.35MPa to spray the alloy melt on a copper cooling roll with a linear speed of 25m/s to obtain a thickness of 15- Alloy thin strip of 18 μm and width of 20 mm. The XRD pattern of the alloy is shown in Figure 1, which shows that the alloy strip has an amorphous structure.

The amorphous alloy strip obtained in this example is used as the solder, and stacked in sequence according to the order of silicon nitride ceramic substrate, solder and copper foil, wherein the thickness of the silicon nitride ceramic substrate is 0.5 mm, and the thickness of the amorphous alloy strip is 0.5 mm. 15-18μm, the thickness of copper foil is 0.3mm. Place the stacked three materials in the fixture, and apply a pressure of 1.0*10 ⁵ Pa on the stacked copper foil, then put the whole into a vacuum brazing furnace, and heat up at a heating rate of 10°C/min. When the temperature reaches 1050°C, keep it warm for 10 minutes, then cool to room temperature with the furnace, and take out the silicon nitride ceramic copper-clad substrate sample.

Measure the peel strength between the silicon nitride ceramic substrate and copper foil in the sample and the thermal cycle performance of the sample at -40°C-150°C. The brazed silicon nitride ceramic copper-clad substrate was cut into 10 identical samples, and the peel strength between the silicon nitride ceramic substrate and copper foil was measured, and the measured value was 12-15N/mm ² . After the silicon nitride ceramic copper-clad substrate is subjected to 5000 cycles of cooling and heating, the measured peel strength between the silicon nitride ceramic substrate and the copper foil is 10-14N/mm ² .

Example 2

A connection layer material for silicon nitride ceramic copper-clad substrate proposed in this embodiment and its preparation and use method, according to the material composition Cu ₅₂ Ti ₈ Zr ₇ Nb ₂ Al _12.5 Ag _0.5 Sn ₁₈ (at.%) The batching is carried out, the total weight is 10 kg, and it is melted in a vacuum induction furnace. The highest temperature during the melting process of the alloy is 1750 °C. Put it into the quartz tube of vacuum spray belt, remelt with induction coil, when the temperature of alloy melt reaches 1120℃, use the pressure of 0.36MPa, spray cast the alloy melt on the copper cooling roller with a line speed of 25m/s, and obtain the thickness The XRD spectrum of the alloy is shown in Figure 2, indicating that the alloy strip is an amorphous structure.

The amorphous alloy strip obtained in this example is used as the solder, and stacked in sequence according to the order of silicon nitride ceramic substrate, solder and copper foil, wherein the thickness of the silicon nitride ceramic substrate is 0.64 mm, and the thickness of the amorphous alloy strip is 0.64 mm. 18-20μm, the thickness of copper foil is 0.5mm. Place the stacked three materials in the fixture, and apply a pressure of 1.5*10 ⁵ Pa on the stacked copper foil, then put the whole into a vacuum brazing furnace, and heat up at a heating rate of 10°C/min. When the temperature reaches 1030°C, keep it warm for 15 minutes, then cool to room temperature with the furnace, and take out the silicon nitride ceramic copper-clad substrate sample.

Measure the peel strength between the silicon nitride ceramic substrate and copper foil in the sample and the thermal cycle performance of the sample at -40°C-150°C. The brazed silicon nitride ceramic copper-clad substrate was cut into 10 identical samples, and the peel strength between the silicon nitride ceramic substrate and the copper foil was measured, and the measured value was 10-14N/mm ² . After the silicon nitride ceramic copper-clad substrate is subjected to 5000 cycles of cooling and heating, the measured peel strength between the silicon nitride ceramic substrate and the copper foil is 9-12N/mm ² .

Finally, it should also be noted that in this disclosure, relative terms such as left and right, first and second, etc., if any, are used only to distinguish one entity or operation from another , without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Although the present disclosure has been disclosed above through the description of the specific embodiments of the present disclosure, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present disclosure within the spirit and scope of the appended schemes. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed by the present disclosure.

Claims (10)

1. The Cu-based alloy solder is characterized by being Cu-based amorphous alloy and comprising the chemical components of Cu _a Ti _b Zr _c M _d Al _e Ag _f Sn _g Wherein M is one or more of Hf, nb, ta, mo, ni and Cr, a, b, c, d, e, f and g respectively represent the atomic percent of each element, a is more than or equal to 40 and less than or equal to 65, b is more than or equal to 5 and less than or equal to 15, c is more than or equal to 5 and less than or equal to 15, d is more than or equal to 0 and less than or equal to 10,1≤e≤15、0≤f≤5、10≤g≤30，a+b+c+d+e+f+g＝100。

2. the Cu-based alloy brazing filler metal according to claim 1, wherein a + g is 65 or more, 1 or more and d is 6 or less, and f is 0.5 or less.

3. The Cu-based alloy solder according to claim 1, wherein a + g is not less than 70, 1. Ltoreq. D.ltoreq.6, 5. Ltoreq. E.ltoreq.10, and f.ltoreq.0.5.

4. The Cu-based alloy solder according to any one of claims 1 to 3, wherein the solder is an amorphous alloy ribbon or an amorphous alloy powder.

5. The Cu-based alloy solder according to claim 4, wherein the solder is an amorphous alloy ribbon prepared by a rapid solidification technique, and has a thickness of 10-30 μm, preferably 15-20 μm; the width is 10-200mm, preferably 50-100mm.

6. A method for producing the Cu-based alloy solder according to any one of claims 1 to 4, wherein the solder is produced by a rapid solidification technique under vacuum conditions or under an argon protective atmosphere; preferably, the raw materials are smelted by a magnetic suspension smelting method or an induction smelting method, and a calcium oxide crucible is used during the induction smelting.

7. The method of manufacturing a Cu-based alloy filler metal according to claim 6, wherein the method of manufacturing a Cu-based alloy filler metal comprises:

firstly, melting raw materials, wherein the highest temperature in the melting process is 1550-1750 ℃, fully alloying, cooling to 1120-1350 ℃, and casting into an alloy rod;

and remelting the alloy rod, and spray-casting the alloy melt on a cooling roll with the linear speed of 18-35m/s by adopting the pressure of 0.30-0.50MPa when the temperature of the alloy melt reaches 1120-1380 ℃ to obtain the alloy thin strip.

8. A silicon nitride ceramic copper-clad substrate comprising a silicon nitride ceramic substrate, a copper foil and a joining layer interposed between and joining the silicon nitride ceramic substrate and the copper foil, wherein the joining layer is formed by performing a brazing process using the Cu-based alloy brazing filler metal according to any one of claims 1 to 5.

9. The silicon nitride ceramic copper clad substrate of claim 8, wherein the silicon nitride ceramic substrate has a thickness of 0.2-0.7mm, and the copper foil has a thickness of 0.3-1.0mm.

10. A method of manufacturing a silicon nitride ceramic copper clad substrate according to any one of claims 7 to 9, comprising:

sequentially stacking the silicon nitride ceramic substrate, the brazing filler metal and the copper foil in sequence;

placing the stacked three materials in a tool clamp, uniformly pressing the stacked copper foil, then sending the copper foil into a furnace for brazing treatment, and then cooling the copper foil along with the furnace to obtain a silicon nitride copper-clad substrate;

preferably, the pressure application treatment is 1.0 x 10 addition ⁴ Pa-3.0*10 ⁵ Pressure of Pa.

Preferably, the brazing process comprises: heating at a heating rate of 10-50 deg.C/min, and maintaining at 1020-1060 deg.C for 10-60min.

Images