Nano rare earth composite enhanced high-performance ceramic chopper and preparation method and application thereof

Abstract

The invention discloses a nano rare earth composite enhanced high-performance ceramic chopper as well as a preparation method and application thereof. The ceramic chopper is prepared from the following raw materials in percentage by mass: 85 to 95 percent of aluminum oxide powder, 2 to 10 percent of zirconium oxide powder, 0.5 to 2 percent of dysprosium oxide powder, 1 to 2 percent of magnesium oxide powder and 0.5 to 1.5 percent of yttrium oxide powder. The ceramic chopper is prepared from the preparation raw materials through high-temperature sintering. The ceramic chopper has excellent wear resistance, strength, toughness and high-temperature stability, and packaging quality and production efficiency can be remarkably improved when the ceramic chopper is applied to semiconductor packaging.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic materials, and in particular to a nano rare earth composite reinforced high-performance ceramic splitting knife and a preparation method and application thereof. Background Art

[0002] Ceramic splitter, also known as porcelain nozzle, capillary (literal translation of English name). Ceramic splitter is a special ceramic tool that occupies an indispensable position in the semiconductor packaging industry. In IC packaging, there are three conventional methods to achieve circuit connection between chip and substrate: flip chip soldering, automatic tape soldering and wire bonding. At present, more than 90% of the connection methods are wire bonding. Wire bonding technology is mainly used in low-cost traditional packaging, mid-range packaging, memory chip stacking, etc. The ceramic splitter is the most important consumable tool in wire stitching.

[0003] Ceramic splitters are axially symmetrical ceramic tools with vertical holes. They play an irreplaceable role in the field of semiconductor wire bonding welding because of their advantages such as high hardness, high wear resistance, high temperature resistance, chemical corrosion resistance, high surface finish and high dimensional accuracy. Wire bonding is the process of pasting the chip electrodes face up on the package base and connecting the chip electrodes to the corresponding electrodes on the lead frame by welding with metal wires. The purpose of wire bonding is to electrically connect the chip to the external package frame to ensure smooth transmission of electrical signals. The operation of wire bonding is similar to that of a high-tech micro "sewing machine", which can use extremely fine wires to sew a chip to another chip or substrate. The role of the ceramic splitter is like the "sewing needle" that threads the needle. A bonding machine needs to bond millions of solder joints every day under full load working conditions. Each ceramic splitter has a fixed service life. Once the rated number of times is reached, a new splitter needs to be replaced. It is conceivable that the demand for ceramic splitters is very large.

[0004] It can be seen that in the semiconductor packaging process, ceramic splitters are a key tool, and their performance directly affects the packaging quality and efficiency. Traditional ceramic splitters often face problems such as insufficient wear resistance and high temperature deformation during use, which seriously affects product yield and production efficiency. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a nano rare earth composite enhanced high performance ceramic splitter and its preparation method and application. The ceramic splitter has excellent wear resistance, strength, toughness and high temperature stability, and can significantly improve the packaging quality and production efficiency when used in semiconductor packaging.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] On the one hand, the present invention provides a nano rare earth composite reinforced high-performance ceramic splitting knife. The raw materials for preparing the ceramic splitting knife include the following components in terms of mass percentage: 85%-95% of aluminum oxide powder, 2%-10% of zirconium oxide powder, 0.5%-2% of dysprosium oxide powder, 1%-2% of magnesium oxide powder and 0.5%-1.5% of yttrium oxide powder; the ceramic splitting knife is made by high-temperature sintering using the raw materials for preparation.

[0008] Furthermore, the particle size of the dysprosium oxide powder is 20-50 nm.

[0009] Furthermore, the ceramic splitting tool contains DyAlO3 and Dy2Zr2O7 oxide phases.

[0010] Furthermore, in the raw materials for preparing the ceramic splitter, the mass percentage of dysprosium oxide powder is 1.0%-1.5%.

[0011] On the other hand, the present invention provides a method for preparing a nano rare earth composite enhanced high-performance ceramic splitter, comprising the following steps: weighing each raw material powder according to the formula ratio; mixing the raw material powder by wet ball milling, and then drying, granulating, forming and sintering to obtain a ceramic splitter semi-finished product.

[0012] Furthermore, in the above preparation method, the wet ball milling uses anhydrous ethanol as a dispersion medium, and the ball milling time is 12-24 hours.

[0013] Furthermore, the forming process adopts a dry pressing forming process, specifically: using a hydraulic press to dry press the material at a pressure of 200-300MPa.

[0014] Furthermore, in the above preparation method, the sintering temperature is 1500-1650° C., and the sintering holding time is 2-3 hours.

[0015] Furthermore, the ceramic splitting knife semi-finished product is ground and polished to obtain the nano rare earth composite enhanced high-performance ceramic splitting knife.

[0016] The invention also provides application of the nano rare earth composite enhanced high performance ceramic splitting knife in semiconductor chip packaging.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention uses 2%-10% zirconium oxide as a toughening phase to improve the fracture toughness of the material, improve the impact resistance of the ceramic splitter, and reduce the risk of fracture during use; the present invention uses 1%-2% magnesium oxide as a sintering aid to promote densification, inhibit abnormal grain growth, improve sintering performance, and ensure the uniformity and density of the product; the present invention uses 0.5%-1.5% yttrium oxide as a stabilizer to stabilize the tetragonal phase ZrO2, and synergizes with Dy2O3 to further enhance the high-temperature stability of the material, and forms a composite rare earth reinforcement system with dysprosium;

[0019] (2) The raw material of the present invention uses 0.5%-1.5% dysprosium oxide, and the ionic radius of dysprosium is Between and The particle size of dysprosium oxide is controlled within the nanometer range, and it can be evenly dispersed in the Al2O3 matrix to form a nano-enhanced phase. Specifically, 0.5%-1.5% dysprosium oxide in the system of the present invention has the following effects:

[0020] High temperature stability: Dysprosium ions can occupy Al at high temperatures 3+ The lattice position forms a stable Al2O3-Dy2O3 solid solution, which significantly improves the high-temperature structural stability of the material and can also increase the hardness of the material through lattice distortion;

[0021] Grain boundary pinning effect: An appropriate amount of nano-sized Dy2O3 particles forms pinning points at the grain boundaries, which can inhibit the abnormal growth of Al2O3 grains during the sintering process, ensuring that the final product has a fine and uniform grain structure, thereby improving the mechanical properties of the material;

[0022] Formation of complex oxides: Formation of complex oxide phases DyAlO3 and Dy2Zr2O7 with Al2O3 and ZrO2, further enhancing the high temperature performance of the material;

[0023] Optical property regulation: The addition of dysprosium can adjust the optical properties of ceramics, which is beneficial for online monitoring of the working status of the splitter;

[0024] Effect on magnesium oxide: a small amount of Dy 3+ It can promote the segregation of MgO at the Al2O3 grain boundary, enhance the grain boundary strength, and improve the fracture toughness of the material;

[0025] High temperature creep resistance: Dy 3+ Ions can effectively inhibit dislocation movement and grain boundary sliding at high temperatures, significantly improving the material's high-temperature creep resistance. This feature allows the ceramic splitter to maintain excellent dimensional stability during long-term high-temperature use;

[0026] Thermal expansion coefficient regulation: The right amount of Dy2O3 can reduce the thermal expansion coefficient of the Al2O3 matrix, reduce thermal stress, and improve the thermal shock resistance of the ceramic splitter;

[0027] Surface performance optimization: The addition of Dy can improve the physical and chemical properties of the ceramic surface, increase the surface hardness and wear resistance, while reducing the surface energy and adhesion, which is beneficial to improving the service life and work efficiency of the ceramic splitting tool. DETAILED DESCRIPTION

[0028] The technical solutions in the present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The invention provides a nano rare earth composite reinforced high-performance ceramic splitting knife. The raw materials for preparing the ceramic splitting knife include the following components in terms of mass percentage: 85%-95% of aluminum oxide powder, 2%-10% of zirconium oxide powder, 0.5%-2% of dysprosium oxide powder, 1%-2% of magnesium oxide powder and 0.5%-1.5% of yttrium oxide powder. The ceramic splitting knife is prepared by sintering the raw materials at high temperature.

[0030] The dysprosium oxide powder is prepared by a sol-gel method and has a particle size of 20-50 nm. Such nano-scale particles can be evenly dispersed in the Al2O3 matrix to form a nano-enhanced phase.

[0031] The ceramic splitting tool contains DyAlO3 and Dy2Zr2O7 oxide phases.

[0032] Preferably, the mass percentage of dysprosium oxide powder in the raw materials for preparing the ceramic splitter is 1.0-1.5%.

[0033] The preparation method of the nano rare earth composite enhanced high-performance ceramic splitter comprises the following steps:

[0034] S1, raw material preparation: weigh each raw material powder according to mass percentage;

[0035] S2, ball milling and mixing: placing the raw material powder in a ball mill, adding anhydrous ethanol as a dispersion medium, and ball milling for 12-24 hours to obtain a mixed slurry;

[0036] S3, spray drying: the mixed slurry is made into particles by spray drying equipment;

[0037] S4, granulation: screening and shaping the dried granules;

[0038] S5, dry pressing: dry pressing is performed using a hydraulic press at a pressure of 200-300 MPa;

[0039] S6, sintering: sintering at 1500-1650°C for 2-3 hours to obtain a semi-finished ceramic splitting knife;

[0040] S7, post-processing: grinding and polishing the sintered ceramic splitting knife semi-finished product to obtain the nano rare earth composite enhanced high-performance ceramic splitting knife.

[0041] The nano rare earth composite enhanced high performance ceramic splitter can be applied to semiconductor chip packaging.

[0042] The present invention is further described in detail below through specific examples.

[0043] Example 1

[0044] A nano rare earth composite reinforced high-performance ceramic splitter, the raw materials for preparing the ceramic splitter include the following components in terms of mass percentage: 90.2% of aluminum oxide powder, 7% of zirconium oxide powder, 0.8% of dysprosium oxide powder, 1.5% of magnesium oxide powder and 0.5% of yttrium oxide powder.

[0045] The preparation method of the nano rare earth composite enhanced high-performance ceramic splitter comprises the following steps:

[0046] S1, raw material preparation: weigh each raw material powder according to mass percentage;

[0047] S2, ball milling: placing the raw material powder in a ball mill, adding anhydrous ethanol as a dispersion medium, and ball milling for 24 hours to obtain a mixed slurry;

[0048] S3, spray drying: the mixed slurry is made into particles by spray drying equipment;

[0049] S4, granulation: screening and shaping the dried granules;

[0050] S5, dry pressing: dry pressing is performed using a hydraulic press at a pressure of 200 MPa;

[0051] S6, sintering: sintering at 1650° C. for 2 hours to obtain a semi-finished ceramic splitting knife;

[0052] S7, post-processing: grinding and polishing the sintered ceramic splitting knife semi-finished product to obtain the nano rare earth composite enhanced high-performance ceramic splitting knife.

[0053] Example 2

[0054] A nano rare earth composite reinforced high-performance ceramic splitter, the raw materials for preparing the ceramic splitter include the following components in terms of mass percentage: 89.8% of aluminum oxide powder, 7% of zirconium oxide powder, 1.2% of dysprosium oxide powder, 1.5% of magnesium oxide powder and 0.5% of yttrium oxide powder.

[0055] The preparation method of the nano rare earth composite enhanced high performance ceramic splitter of Example 2 is the same as that of Example 1.

[0056] Example 3

[0057] A nano rare earth composite reinforced high-performance ceramic splitter, the raw materials for preparing the ceramic splitter include the following components in terms of mass percentage: 89.3% aluminum oxide powder, 7% zirconium oxide powder, 1.7% dysprosium oxide powder, 1.5% magnesium oxide powder and 0.5% yttrium oxide powder.

[0058] The preparation method of the nano rare earth composite enhanced high performance ceramic splitting knife of Example 3 is the same as that of Example 1.

[0059] Comparative Example 1

[0060] A ceramic splitting knife. The raw materials for preparing the ceramic splitting knife include the following components according to mass percentage: 91% of aluminum oxide powder, 7% of zirconium oxide powder, 1.5% of magnesium oxide powder and 0.5% of yttrium oxide powder.

[0061] The preparation method of the nano rare earth composite enhanced high performance ceramic splitter of Comparative Example 1 is the same as that of Example 1.

[0062] Comparative Example 2

[0063] A nano rare earth composite reinforced high-performance ceramic splitter, the raw materials for preparing the ceramic splitter include the following components in terms of mass percentage: 90.7% aluminum oxide powder, 7% zirconium oxide powder, 0.3% dysprosium oxide powder, 1.5% magnesium oxide powder and 0.5% yttrium oxide powder.

[0064] The ceramic splitters of Examples 1-3 and Comparative Examples 1 and 2 were subjected to performance tests, including room temperature flexural strength, 1400°C high temperature flexural strength, Vickers hardness, fracture toughness, wear resistance (wear volume loss) and high temperature dimensional stability. The test equipment, method and sample quantity of each item are as follows, wherein the sample is made into a test bar with a size of 3 mm×4 mm×36 mm.

[0065] a) Room temperature flexural strength test

[0066] Equipment: Universal material testing machine;

[0067] Method: Three-point bending method, support span 30 mm, loading rate 0.5 mm / min;

[0068] Number of samples: 5 per group;

[0069] b) High temperature bending strength test

[0070] Equipment: high temperature universal material testing machine;

[0071] Method: Three-point bending test was carried out at 1400℃, and other parameters were the same as those tested at room temperature;

[0072] Number of samples: 5 per group;

[0073] c) Vickers hardness test

[0074] Equipment: Vickers hardness tester;

[0075] Method: Load 10kg and hold for 15s;

[0076] Sample quantity: 5 points are tested in each group and the average value is taken;

[0077] d) Fracture toughness test

[0078] Equipment: Universal material testing machine;

[0079] Method: Single edge notched beam method (SENB), notch depth 2 mm;

[0080] Number of samples: 5 per group;

[0081] e) Wear resistance test

[0082] Equipment: ball-on-disc friction and wear tester;

[0083] Method: The dual ball is a zirconia ball with a diameter of 6 mm, a load of 10 N, a rotation speed of 200 rpm, and a time of 2 hours;

[0084] Number of samples: 3 per group;

[0085] f) High temperature dimensional stability test

[0086] Equipment: High temperature dilatometer;

[0087] Method: Heat from room temperature to 1500°C, hold for 4 hours, and measure the linear shrinkage;

[0088] Number of samples: 3 per group.

[0089] The performance test results are shown in Table 1.

[0090] Table 1

[0091]

[0092] The results are analyzed as follows:

[0093] Room temperature flexural strength: The room temperature flexural strength of the ceramic splitter of the embodiment of the present invention is improved compared with that of comparative examples 1 and 2. This is mainly attributed to the nano-scale precipitation phases formed by an appropriate amount of Dy2O3 at the grain boundary, which play a pinning role, inhibit grain growth, and refine the grain structure;

[0094] High temperature bending strength: At a high temperature of 1400°C, the bending strength of the ceramic splitter of the embodiment of the present invention is higher than that of the comparative example. This is due to the complex oxides formed by appropriate amounts of Dy2O3, ZrO2 and Y2O3, such as Dy2Zr2O7, which have excellent phase stability at high temperatures, effectively inhibit atomic diffusion and grain boundary sliding at high temperatures, and significantly improve the high temperature strength and creep resistance of the material;

[0095] Vickers hardness: The hardness of the ceramic splitter in the embodiment of the present invention is higher than that in the comparative example. This is because Dy 3+ Partially replace Al 3+ The formation of solid solution introduces lattice distortion, increases the resistance to dislocation movement, and thus improves the strength and hardness of the material;

[0096] Fracture toughness: The fracture toughness of the ceramic splitting cutter of the embodiment of the present invention is improved, which is mainly due to two aspects: first, the addition of Dy2O3 promotes the stabilization of the tetragonal phase of ZrO2 and enhances the stress-induced phase transformation toughening effect; second, the nano-scale Dy2O3 particles form a stress field at the crack tip, which plays a role in deflecting and passivating the crack.

[0097] Wear resistance: The wear resistance of the ceramic splitter in the embodiment of the present invention is significantly improved compared with the comparative example, and the wear volume loss is greatly reduced. This is because the appropriate amount of nano-scale Dy2O3 particles form uniformly distributed hard points on the surface, which increases the wear resistance of the material. At the same time, the presence of Dy reduces the surface energy of the material, reduces the adhesion to the workpiece, and further improves the wear resistance.

[0098] High temperature dimensional stability: After being kept at 1500°C for 4 hours, the linear shrinkage of the ceramic splitter of the embodiment of the present invention is lower than that of the comparative example. This proves that the addition of an appropriate amount of Dy2O3 significantly improves the high temperature structural stability of the material, which is crucial for maintaining the geometric accuracy of the ceramic splitter during use. 3+ Ions can effectively inhibit dislocation movement and grain boundary sliding at high temperatures, significantly improving the high-temperature creep resistance of the material.

[0099] The ceramic splitting knife samples of Example 2 and Comparative Example 1 were observed by scanning electron microscope (SEM), and the results showed that the average grain size of the sample of Comparative Example 1 was 2.5 μm, and the grain distribution was relatively uneven. The average grain size of the sample of Example 2 was 1.2 μm, and the grain distribution was more uniform, and nano-scale second phase particles were observed at the grain boundaries.

[0100] The long-term performance of the ceramic splitting knife samples of Example 2 and Comparative Example 1 was evaluated, and the test conditions were: temperature 1200°C, number of cycles 10,000 times, each cycle: heating to 1200°C for 10 minutes, and then cooling to room temperature; the results showed that the sample of Comparative Example 1 had a permanent dimensional change of 0.8% after 10,000 cycles, and the sample of Example 2 had only a permanent dimensional change of 0.2% after 10,000 cycles; the surface roughness Ra value of the sample of Comparative Example 1 increased from the initial 0.2 μm to 1.5 μm, and the surface roughness Ra value of the sample of Example 2 increased from the initial 0.2 μm to only 0.6 μm; the room temperature flexural strength of the sample of Comparative Example 1 decreased by 25% after 10,000 cycles, and the room temperature flexural strength of the sample of Example 2 decreased by only 8% after 10,000 cycles; the sample surface was observed using a fluorescent penetrant detection method, and the surface microcrack density of the sample of Comparative Example 1 reached 15 lines / cm after 10,000 cycles 2 After 10,000 cycles, the surface microcrack density of the sample in Example 2 is only 3 / cm 2 .

[0101] As can be seen from the above, the ceramic splitter of the present invention exhibits excellent high-temperature dimensional stability, which is attributed to the structural stability of the complex oxide phase formed by Dy2O3 at high temperatures, which effectively inhibits the creep and grain boundary sliding of the material. The ceramic splitter of the present invention also has better wear resistance and surface stability, which is mainly due to the uniformly distributed hard points formed by Dy2O3 on the surface and its effect of reducing surface energy; the ceramic splitter of the present invention has better fatigue resistance and structural stability, which is due to the addition of Dy2O3 to enhance the grain boundary strength and inhibit grain boundary sliding and microcrack extension at high temperatures; the ceramic splitter of the present invention has superiority in long-term high-temperature cyclic use, and the addition of Dy2O3 not only improves the fracture toughness of the material, but also enhances the material's resistance to thermal fatigue by forming a complex oxide phase.

[0102] The ceramic splitting knife of the present invention is applied to the semiconductor packaging process, has a long service life, and can significantly improve the yield rate and packaging precision of the packaged products.

[0103] The ceramic splitter of the present invention has multiple strengthening mechanisms: grain refinement, solid solution strengthening, second phase strengthening and phase transformation toughening, etc. The appropriate amount of Dy, Zr and Y can form a composite rare earth strengthening system to achieve a synergistic effect and further improve the high temperature performance and structural stability of the material. The ceramic splitter of the present invention can be realized on the existing production line without large-scale equipment modification, and has good mass production stability and cost-effectiveness.

[0104] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0105] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A nano rare earth composite enhanced high performance ceramic splitter, characterized in that: The raw materials for preparing the ceramic splitting knife include the following components in terms of mass percentage: 85%-95% of aluminum oxide powder, 2%-10% of zirconium oxide powder, 0.5%-2% of dysprosium oxide powder, 1%-2% of magnesium oxide powder and 0.5%-1.5% of yttrium oxide powder; the ceramic splitting knife is prepared by adopting the raw materials for preparation through high-temperature sintering.

2. The nano rare earth composite enhanced high performance ceramic splitting knife according to claim 1, characterized in that: The particle size of the dysprosium oxide powder is 20-50 nm.

3. The nano rare earth composite enhanced high performance ceramic splitting knife according to claim 1, characterized in that: The ceramic splitting tool contains DyAlO3 and Dy2Zr2O7 oxide phases.

4. The nano rare earth composite enhanced high performance ceramic splitting knife according to claim 1, characterized in that: The mass percentage of dysprosium oxide powder in the raw materials for preparing the ceramic splitter is 1.0%-1.5%.

5. A method for preparing the nano rare earth composite enhanced high performance ceramic splitter according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: weighing raw material powders according to the formula ratio; mixing the raw material powders through wet ball milling, and then drying, granulating, forming and sintering to obtain a ceramic splitter semi-finished product.

6. The method for preparing the nano rare earth composite enhanced high performance ceramic splitter according to claim 5, characterized in that: The wet ball milling uses anhydrous ethanol as a dispersion medium, and the ball milling time is 12-24 hours.

7. The method for preparing the nano rare earth composite enhanced high performance ceramic splitter according to claim 5, characterized in that: The forming process adopts a dry pressing forming process, specifically: using a hydraulic press to dry press the material under a pressure of 200-300MPa.

8. The method for preparing the nano rare earth composite enhanced high performance ceramic splitter according to claim 5, characterized in that: The sintering temperature is 1500-1650°C, and the sintering holding time is 2-3 hours.

9. The method for preparing the nano rare earth composite enhanced high performance ceramic splitter according to claim 5, characterized in that: The ceramic splitting knife semi-finished product is ground and polished to obtain the nano rare earth composite enhanced high-performance ceramic splitting knife.

10. Use of the nano rare earth composite enhanced high performance ceramic splitter according to any one of claims 1 to 4 in semiconductor chip packaging.

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