Microwave dielectric ceramic material with continuously adjustable thermal expansion coefficient, three-dimensional multilayer switching substrate and preparation method of three-dimensional multilayer switching substrate

Abstract

The invention provides a microwave dielectric ceramic material with a continuously adjustable thermal expansion coefficient, a three-dimensional multi-layer switching substrate and a preparation method of the three-dimensional multi-layer switching substrate, and belongs to the technical field of electronic components. The chemical formula of the microwave dielectric ceramic material with the continuously adjustable thermal expansion coefficient is A < 1-x > B < x > DyOz. According to the microwave dielectric ceramic material provided by the invention, the continuous adjustment of the thermal expansion coefficient can be realized by adjusting the types of the elements and the ratio of the elements, and the microwave dielectric ceramic material also has excellent dielectric properties; the material can be used for preparing a heterogeneous co-fired three-dimensional multilayer ceramic substrate of which the thermal expansion coefficient gradually changes from small to large, the heterogeneous co-fired three-dimensional multilayer ceramic substrate is used as a transfer layer between an integrated circuit chip and a PCB (Printed Circuit Board) support plate, and the expansion coefficient of a surface layer connected with the integrated circuit chip is close to that of the integrated circuit chip; and the expansion coefficient of the bottom layer connected with the PCB support plate is close to that of the PCB support plate, so that the interconnection between the integrated circuit chip and the PCB support plate is realized.

Description

Technical Field

[0001] The present application relates to the technical field of electronic components, and more particularly, to a microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion, a three-dimensional multi-layer transfer substrate and a preparation method thereof. Background Art

[0002] With the rapid development of the electronics and communication industries, electronic components have entered the trend of integration and miniaturization. As the packaging carrier of semiconductor chips, electronic substrates constitute electronic circuits by carrying electronic components. As a typical electronic substrate material, microwave dielectric ceramic materials have become the key technology for the development of large-scale integrated circuits and electronic packaging due to their designable microwave dielectric properties and the advantages of realizing multi-layer integrated design through multi-layer ceramic technologies (such as HTCC, LTCC).

[0003] In the physical property system of electronic substrate materials, the adaptability of the coefficient of thermal expansion is of decisive significance. In electronic packaging modules, microwave dielectric ceramic materials are typical substrate materials, which need to match the coefficient of thermal expansion with adjacent components. However, there are differences in the coefficients of thermal expansion between different components, such as single-crystalline silicon (3.5 ppm / °C) and GaAs (5.7 ppm / °C), and PCB carriers (such as FR4: 13 - 18 ppm / °C). When used as three-dimensional multi-layer transfer substrates, this contradiction is more serious. The coefficient of thermal expansion of traditional homogeneous multi-layer substrate materials is fixed, and it is impossible to achieve good thermal expansion matching with chips and PCB carriers simultaneously, easily resulting in thermal stress, micro-cracks and other thermal mismatch problems, reducing the reliability and stability of the packaging system. Therefore, it is urgent to develop a new microwave dielectric ceramic system with adjustable coefficient of thermal expansion to co-fire and form a heterogeneous multi-layer structure with a gradient change in the coefficient of thermal expansion, so that it can simultaneously match semiconductor materials with a lower coefficient of thermal expansion and PCB carrier materials with a higher coefficient of thermal expansion. Summary of the Invention

[0004] The present application provides a microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion, a three-dimensional multi-layer transfer substrate and a preparation method thereof, which can achieve continuous adjustment of the coefficient of thermal expansion to meet the requirements of integration and miniaturization of electronic components, and achieve good matching of the coefficient of thermal expansion between multi-layer ceramic structures and different modules.

[0005] The embodiments of the present application are implemented as follows:

[0006] In a first aspect, an example of the present application provides a microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion, and its chemical formula is A 1-x B x D y O z; wherein, A and B are each independently selected from any one or more of Zn, Mg, Ca, Sr, Ba, Fe, Co, Ni, and Cu, x is from 0 to 1, and the elements selected for A and B are different; D is selected from W, Mo, Si, Ge, Sn, Se, V, Bi, or S.

[0007] In the above technical solution, the microwave dielectric ceramic material of the present application can continuously adjust the coefficient of thermal expansion by adjusting the types and ratios of metal elements, and the microwave dielectric ceramic material also has excellent dielectric properties. Furthermore, a heterogeneous ceramic substrate with a continuously varying coefficient of thermal expansion from small to large can be designed, which is used as a multi-layer ceramic structure between an integrated circuit chip and a PCB carrier board, thereby realizing the interconnection between the integrated circuit chip and the PCB carrier board.

[0008] In some embodiments, A and B are each independently selected from Zn, Mg, Ca, Sr, Ba, Fe, Co, Ni, or Cu.

[0009] In the above example, the microwave dielectric ceramic material of the present application includes two metal elements, and the coefficient of thermal expansion can be continuously adjusted by adjusting the types of metal elements and the ratio of the two metal elements, and the microwave dielectric ceramic material also has excellent dielectric properties.

[0010] In some embodiments, the above microwave dielectric ceramic material satisfies the following conditions: a. The relative dielectric constant is 5.5 to 12.5; b. The quality factor is 3000 GHz to 300000 GHz; c. The temperature coefficient of resonant frequency is -100 ppm / °C to +30 ppm / °C; d. The coefficient of thermal expansion is -5 ppm / °C to 15 ppm / °C.

[0011] In the above example, the microwave dielectric ceramic material of the present application has excellent dielectric properties and can continuously adjust the coefficient of thermal expansion in the range of -5 ppm / °C to 15 ppm / °C.

[0012] In a second aspect, the present application provides a method for preparing the above microwave dielectric ceramic material with a continuously adjustable coefficient of thermal expansion, which includes: pre-sintering raw materials at a temperature of 1000°C to 1250°C for 1 h to 24 h to obtain a pre-sintered material, then granulating and pressing the pre-sintered material into a shape, and then successively removing the binder at a temperature of 300°C to 600°C for 2 h to 12 h and sintering at a temperature of 800°C to 1700°C for 1 h to 24 h to obtain the microwave dielectric ceramic material; the raw materials include oxides or salts of element A, element B, and element D.

[0013] In the above technical solution, the preparation method of the microwave dielectric ceramic material of the present application first makes the raw materials undergo preliminary reaction through presintering to obtain a presintered material, and the microwave dielectric ceramic material can be obtained by granulating the presintered material, pressing it into a shape, and then performing secondary sintering. The preparation method of the microwave dielectric ceramic material of the present application is simple, and the obtained microwave dielectric ceramic material has excellent dielectric properties and the thermal expansion coefficient can be continuously adjusted between -5 ppm / °C and 15 ppm / °C.

[0014] In some embodiments, before presintering the raw materials, the raw materials are first subjected to a first ball milling treatment and sieved through 140 meshes after drying.

[0015] In the above example, the first ball milling treatment can make the raw materials evenly mixed before presintering.

[0016] In some embodiments, before granulating the above presintered material, the presintered material is first subjected to a second ball milling treatment and sieved through 120 meshes and 60 meshes in sequence after drying.

[0017] In the above example, the second ball milling treatment can disperse the massive presintered material formed by presintering.

[0018] In a third aspect, the present application example provides a three-dimensional multi-layer interposer substrate, which includes a multi-layer ceramic structure and a vertical interconnection structure arranged in layers along the thickness direction in sequence. The multi-layer ceramic structure has a chip connection port for electrically connecting with an integrated circuit chip and a PCB connection port for electrically connecting with a PCB carrier board. Electrical connection is achieved between the multi-layer ceramic structures through the vertical interconnection structure; each layer of ceramic structure includes a main body and an interconnection circuit. The main body includes the microwave dielectric ceramic material with a continuously adjustable thermal expansion coefficient in the above embodiments. The thermal expansion coefficient of the multi-layer ceramic structure increases along the thickness direction, and the interconnection circuit is distributed on the surface and / or inside of the main body.

[0019] In the above technical solution, the three-dimensional multi-layer interposer substrate of the present application includes a multi-layer ceramic structure with a thermal expansion coefficient increasing along the thickness direction. The chip connection port and the PCB connection port of the multi-layer ceramic structure are respectively used to be combined with the integrated circuit chip and the PCB carrier board, so that the thermal expansion coefficients of the two ends of the multi-layer ceramic structure match the thermal expansion coefficients of the integrated circuit chip and the PCB carrier board respectively.

[0020] In a fourth aspect, an example of the present application provides a three-dimensional multi-layer packaging module, which includes an integrated circuit chip, the three-dimensional multi-layer interposer substrate in the above embodiment, and a PCB carrier board arranged in sequence along the height direction. The coefficient of thermal expansion of the integrated circuit chip is less than that of the PCB carrier board. The difference between the coefficient of thermal expansion of the ceramic structure combined with the integrated circuit chip and the coefficient of thermal expansion of the integrated circuit chip is 0 to 5 ppm / °C, and the difference between the coefficient of thermal expansion of the ceramic structure combined with the PCB carrier board and the coefficient of thermal expansion of the PCB carrier board is 0 to 5 ppm / °C.

[0021] In the above technical solution, in the three-dimensional multi-layer packaging module of the present application, by matching the coefficient of thermal expansion of the ceramic structure combined with the PCB carrier board with that of the PCB carrier board, and enabling the ceramic structure combined with the integrated circuit chip to match the coefficient of thermal expansion of the integrated circuit chip, and the coefficient of thermal expansion of adjacent two-layer ceramic structures can also match, thereby improving or avoiding thermal mismatch problems such as thermal stress and microcracks in the three-dimensional multi-layer packaging module.

[0022] In some embodiments, the number of layers of the above three-dimensional multi-layer interposer substrate is 2 to 100 layers.

[0023] In some embodiments, the difference between the coefficients of thermal expansion of any adjacent two-layer ceramic structures in the three-dimensional multi-layer interposer substrate is 0 to 5 ppm / °C.

[0024] In the above example, the difference in the coefficient of thermal expansion between adjacent two-layer ceramic structures is small, thereby improving or avoiding thermal mismatch problems such as thermal stress and microcracks in the three-dimensional multi-layer packaging module. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic structural diagram of the three-dimensional multi-layer packaging module of the embodiment of the present application.

[0027] Figure 2 It is an SEM image of the microwave dielectric ceramic prepared in Embodiment 1 of the present application.

[0028] Figure 3 It is an SEM image of the heterogeneous multi-layer microwave dielectric ceramic prepared in Embodiment 9 of the present application.

[0029] Reference Signs: 01 - Three-dimensional multi-layer packaging module; 001 - Integrated circuit chip; 002 - Three-dimensional multi-layer interposer substrate; 003 - PCB carrier board. Detailed implementation mode

[0030] In order to improve or avoid thermal mismatch problems such as thermal stress and microcracks in 3D multi-layer modules, the applicant found that if a heterogeneous ceramic material with a continuously varying coefficient of thermal expansion from small to large is designed and used as the multi-layer ceramic structure between the integrated circuit and the PCB carrier board to achieve the interconnection between the integrated circuit and the PCB carrier board, the above problems can be improved or avoided.

[0031] For the ceramic structure material, the applicant can further combine the ceramic phase with a higher coefficient of thermal expansion and the ceramic phase with a lower coefficient of thermal expansion, and prepare a packaging material with thermophysical properties matching those of the corresponding semiconductor material and excellent microwave dielectric properties by regulating the phase transformation, volume fraction, crystal structure, etc. between the two phases.

[0032] While introducing the second phase to adjust the coefficient of thermal expansion of the ceramic, it is necessary to take into account the microwave dielectric properties of the material itself. Introducing a second phase without microwave properties easily leads to a sharp increase in dielectric loss and performance deterioration. Therefore, it is necessary to reasonably select materials to ensure excellent dielectric properties of the microwave dielectric ceramic material while adjusting the coefficient of thermal expansion.

[0033] The selection of the ceramic structure material is extremely important, and the ceramic structure material is related to the performance of multi-element electronic components. Generally, the requirements for the ceramic structure material are: low relative dielectric constant (to improve the transmission rate and enhance the frequency selection characteristics), high quality factor (to reduce the capacitance crosstalk and noise at high frequencies), near-zero temperature coefficient of resonant frequency, and good thermal stability and mechanical processing performance.

[0034] Based on this, the present application provides a microwave dielectric ceramic material with the chemical formula A 1-x B x D y O z ; wherein, A and B are each independently selected from any one or more of Zn, Mg, Ca, Sr, Ba, Fe, Co, Ni, and Cu, x is 0 to 1, and the elements selected for A and B are different; D is selected from W, Mo, Si, Ge, Sn, Se, V, Bi, or S.

[0035] As an example, A and B can be respectively selected from a single metal element, and A and B are different metal elements; or A is selected from two metal elements, B is selected from a single metal element; or A is selected from two metal elements, B is selected from two metal elements; or A is selected from two metal elements, B is selected from three metal elements; or A is selected from a single metal element, B is selected from two metal elements.

[0036] In some embodiments, A and B are independently selected from Zn, Mg, Ca, Sr, Ba, Fe, Co, Ni, or Cu, and the elements selected for A and B are different.

[0037] As an example, A can be Zn and B can be Mg; or A can be Ca and B can be Mg; or A can be Cu and B can be Sr.

[0038] In some embodiments, the relative dielectric constant of the microwave dielectric ceramic material is 5.5 to 12.5, the quality factor is 3000 GHz to 300000 GHz, and the resonant frequency temperature coefficient is -100 ppm / °C to +30 ppm / °C.

[0039] The microwave dielectric ceramic material of the present application can achieve continuous adjustment of the thermal expansion coefficient by adjusting the types and ratios of metal elements, and the microwave dielectric ceramic material also has excellent dielectric properties. Furthermore, a heterogeneous ceramic substrate with a continuously varying thermal expansion coefficient from small to large can be designed and used as a multi-layer ceramic structure between an integrated circuit chip and a PCB carrier board, thereby realizing the interconnection between the integrated circuit chip and the PCB carrier board.

[0040] The present application also provides a method for preparing the microwave dielectric ceramic material in the above embodiments, which includes the following steps:

[0041] S1. Prepare the pre-sintered material

[0042] First, oxides or salts including element A, element B, and element D are configured according to the chemical formula, and the configured raw materials are subjected to a first ball milling process. After the ball milling is completed, the materials are dried and sieved through a 140-mesh sieve. Then, the sieved raw materials are pre-sintered at a temperature of 1000°C to 1250°C for 1 h to 24 h to obtain the pre-sintered material.

[0043] In some embodiments, the first ball milling process includes mixing the raw materials, zirconia balls, and absolute ethanol in a mass ratio of 1:1 to 3:1 to 3, and ball milling at a rotation speed of 300 r / min to 600 r / min for 8 h to 12 h; drying includes volatilizing the absolute ethanol at 100°C to 200°C.

[0044] As an example, the pre-sintering temperature can be 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, or 1250°C, etc.; the pre-sintering time can be 1 h, 2 h, 3 h, 5 h, 8 h, 10 h, 12 h, 15 h, 16 h, 18 h, 20 h, or 24 h, etc.

[0045] S2. Prepare the microwave dielectric ceramic material

[0046] The prepared pre-sintered material is crushed and ground finely, and then undergoes a second ball-milling treatment. After the ball-milling is completed, it is dried and sieved through 120 mesh and 60 mesh. Then, the sieved pre-sintered material is granulated and pressed into shape, and then debinded at a temperature of 300°C to 600°C for 2h to 12h and sintered at a temperature of 800°C to 1700°C for 1h to 24h in sequence to obtain the microwave dielectric ceramic material.

[0047] In some embodiments, the time of the second ball-milling treatment is 4h to 8h, and the drying temperature is 100°C to 200°C.

[0048] In some embodiments, a binder is added to the pre-sintered material during the granulation process.

[0049] Optionally, the mass of the binder is 8wt% to 15wt% of the mass of the pre-sintered material.

[0050] Optionally, the binder includes 3wt% to 7wt% of polyvinyl alcohol.

[0051] As an example, the debinding temperature of the pre-sintered material can be 300°C, 400°C, 500°C or 600°C, etc., and the debinding time can be 2h, 3h, 5h, 8h, 10h or 12h, etc.; the sintering temperature can be 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1250°C, 1300°C, 1350°C, 1400°C, 1450°C, 1500°C, 1550°C, 1600°C, 1650°C or 1700°C, etc., and the sintering time can be 1h, 2h, 3h, 5h, 8h, 10h, 12h, 15h, 16h, 18h, 20h or 24h, etc.

[0052] The preparation method of the microwave dielectric ceramic material of the present application first makes the raw materials undergo a preliminary reaction through pre-sintering to obtain the pre-sintered material. After granulating and pressing the pre-sintered material into shape, secondary sintering can obtain the microwave dielectric ceramic material. The preparation method of the microwave dielectric ceramic material of the present application is simple, and the obtained microwave dielectric ceramic material has excellent dielectric properties and the thermal expansion coefficient can be continuously adjusted between -5ppm / °C and 15ppm / °C.

[0053] The present application also provides a three-dimensional multi-layer transfer substrate for electronic packaging, which is used to connect an integrated circuit chip and a PCB carrier board. It includes a multi-layer ceramic structure and a vertical interconnection structure arranged in layers along the thickness direction. The multi-layer ceramic structure has a chip connection port for electrically connecting with the integrated circuit chip and a PCB connection port for electrically connecting with the PCB carrier board. Electrical connection between the multi-layer ceramic structures is achieved through the vertical interconnection structure; each layer of the ceramic structure includes a main body and an interconnection circuit. The main body includes the microwave dielectric ceramic material with continuously adjustable thermal expansion coefficient in the above embodiments. The thermal expansion coefficient of the multi-layer ceramic structure increases along the thickness direction, and the interconnection circuit is distributed on the surface and / or inside of the main body.

[0054] The three-dimensional multi-layer transfer substrate of the present application includes a multi-layer ceramic structure with a thermal expansion coefficient increasing along the thickness direction. The chip connection port and the PCB connection port of the multi-layer ceramic structure are respectively used to be combined with the integrated circuit chip and the PCB carrier board, so that the thermal expansion coefficients of the two ends of the multi-layer ceramic structure match the thermal expansion coefficients of the integrated circuit chip and the PCB carrier board respectively.

[0055] The three-dimensional multi-layer transfer substrate can be prepared by a thick film process, and its typical process includes one or more of tape casting, punching, printing, laminating, isothermal treatment, cutting, sintering, etc.

[0056] The three-dimensional multi-layer transfer substrate can be prepared by the following method:

[0057] S1. Prepare the slurry: Mix ceramic powder, organic solvent, dispersant, binder, plasticizer, etc. in a certain proportion, and ball mill to make a uniform and stable ceramic slurry.

[0058] Further, in step 1, the ceramic powder is one or more of the microwave dielectric ceramic materials with continuously adjustable thermal expansion coefficient as described above.

[0059] Further, in step 1, the organic solvent is one or more of ethanol, acetone, toluene, methyl ethyl ketone, etc.

[0060] Further, in step 1, the dispersant is one or more of ammonium polyacrylate, polyvinylpyrrolidone, etc.

[0061] Further, in step 1, the binder is one or more of polyvinyl butyral, polymethyl methacrylate, etc.

[0062] Further, in step 1, the plasticizer is one or more of dibutyl phthalate, dioctyl phthalate, etc.

[0063] S2. Tape casting: Cast the ceramic slurry through a tape casting machine into a ceramic green tape with uniform thickness.

[0064] S3. Punching: Use a laser drilling machine or a mechanical drilling machine to drill through holes or blind holes in the green ceramic tape.

[0065] S4. Printing / Filling holes: Adopt screen printing or inkjet printing technology to print conductive paste on the green ceramic tape, form a circuit pattern, and fill the through holes or blind holes to achieve interlayer interconnection.

[0066] Further, in step 4, the conductive paste is one or more of silver paste, copper paste, gold paste, tungsten paste, molybdenum paste, manganese paste, etc.

[0067] S5. Laminating: Align the laminated green ceramic tapes with printed circuit patterns according to the design requirements.

[0068] S6. Warm isostatic pressing: Put the laminated and aligned green ceramic into a warm isostatic pressing equipment, and press it under a certain temperature and pressure to make the layers closely combined.

[0069] S7. Cutting: Cut the pressed green ceramic into individual multi-layer transfer substrates.

[0070] S8. Sintering: Put the cut multi-layer transfer substrate into a sintering furnace and sinter it at a high temperature to make it densified, and finally form a multi-layer transfer substrate.

[0071] Further, in step 8, the sintering temperature is 800°C to 1700°C, and the sintering time is 1h to 24h.

[0072] Please refer to Figure 1 , this application also provides a three-dimensional multi-layer packaging module 01, which includes an integrated circuit chip 001, the three-dimensional multi-layer transfer substrate 002 in the above embodiment, and a PCB carrier 003 arranged in sequence along the height direction. The coefficient of thermal expansion of the integrated circuit chip 001 is less than that of the PCB carrier 003. The difference between the coefficient of thermal expansion of the ceramic structure combined with the integrated circuit chip 001 and the coefficient of thermal expansion of the integrated circuit chip 001 is 0 to 5 ppm / °C, and the difference between the coefficient of thermal expansion of the ceramic structure combined with the PCB carrier 003 and the coefficient of thermal expansion of the PCB carrier 003 is 0 to 5 ppm / °C.

[0073] As an example, the difference between the coefficient of thermal expansion of the ceramic structure combined with the integrated circuit chip 001 and the coefficient of thermal expansion of the integrated circuit chip 001 can be 0, 1 ppm / °C, 2 ppm / °C, 3 ppm / °C, or 5 ppm / °C, etc. The difference between the coefficient of thermal expansion of the ceramic structure combined with the PCB carrier 003 and the coefficient of thermal expansion of the PCB carrier 003 can be 0, 1 ppm / °C, 2 ppm / °C, 3 ppm / °C, or 5 ppm / °C, etc.

[0074] In some embodiments, the number of layers of the three-dimensional multi-layer interposer substrate 002 is 2 to 100 layers.

[0075] As an example, the number of layers of the three-dimensional multi-layer interposer substrate 002 can be 2 layers, 5 layers, 10 layers, 20 layers, 50 layers, 80 layers, 100 layers, and so on.

[0076] In some embodiments, the difference in the coefficient of thermal expansion between any two adjacent ceramic structures in the three-dimensional multi-layer interposer substrate 002 is 0 to 5 ppm / °C.

[0077] As an example, the difference in the coefficient of thermal expansion between any two adjacent ceramic structures in the three-dimensional multi-layer interposer substrate 002 can be 0, 1 ppm / °C, 2 ppm / °C, 3 ppm / °C, 5 ppm / °C, and so on.

[0078] It should be noted that the difference in the coefficient of thermal expansion between the ceramic structure combined with the integrated circuit chip 001 and the integrated circuit chip 001, the difference in the coefficient of thermal expansion between the ceramic structure combined with the PCB carrier 003 and the PCB carrier 003, and the difference in the coefficient of thermal expansion between any two adjacent ceramic structures can be the same or different.

[0079] In addition, the difference in the coefficient of thermal expansion between any two adjacent ceramic structures at different positions can be the same or different. For example, the difference in the coefficient of thermal expansion between the first ceramic structure and the second ceramic structure is 0.1 ppm / °C, and the difference in the coefficient of thermal expansion between the second ceramic structure and the third ceramic structure is 0.5 ppm / °C.

[0080] The three-dimensional multi-layer packaging module 01 of the present application improves or avoids thermal mismatch problems such as thermal stress and microcracks in the three-dimensional multi-layer packaging module 01 by matching the coefficient of thermal expansion of the ceramic structure combined with the PCB carrier 003 and the PCB carrier 003, and enabling the coefficient of thermal expansion of the ceramic structure combined with the integrated circuit chip 001 to match the integrated circuit chip 001, and also enabling the coefficient of thermal expansion between any two adjacent ceramic structures to match.

[0081] The embodiments of the present application will be described in detail below in conjunction with the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be construed as limiting the scope of the present application. For those not specified in the examples, the operations are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0082] Example 1

[0083] The embodiment of the present application provides a microwave dielectric ceramic material and a preparation method thereof, which include the following steps:

[0084] S1. Preparation of pre-sintered material

[0085] Configure CaCO3, MgO, and SiO2 according to the chemical formula (Ca 0.5 Mg 0.5 )2SiO4, where the molar ratio of CaCO3, MgO, and SiO2 is 1:1:1. Then put the configured raw materials into a ball milling tank, and add zirconia balls and absolute ethanol to the ball milling tank. The mass ratio of the raw materials, zirconia balls, and absolute ethanol is 1:1.5:2. After sealing, place it in a planetary ball mill and ball mill at a speed of 500 r / min for 8 h. After completing the ball milling, take out the raw materials, dry them at 120 °C to volatilize the absolute ethanol, then sieve through 140 meshes. Then evenly spread the sieved raw material powder in a crucible and pre-sinter at a temperature of 1000 °C for 4 h to obtain the pre-sintered material.

[0086] S2. Preparation of microwave dielectric ceramic material

[0087] Pound and grind the obtained pre-sintered material finely, then put it into a ball milling tank, and add zirconia balls and absolute ethanol to the ball milling tank. The mass ratio of the pre-sintered material, zirconia balls, and absolute ethanol is 1:1.5:2. After sealing, place it in a planetary ball mill and ball mill at a speed of 500 r / min for 4 h. After completing the ball milling, take out the pre-sintered material, dry it at 120 °C to volatilize the absolute ethanol, then sieve through 120 meshes and 60 meshes in sequence. Then mix the sieved pre-sintered material with a 5 wt% aqueous solution of polyvinyl alcohol for granulation. The mass of the aqueous solution of polyvinyl alcohol is 10 wt% of the mass of the pre-sintered material. Respectively use the mold and mold to perform uniaxial pressing for forming at a pressure of 150 MPa, and perform cold isostatic pressing at a pressure of 250 MPa to improve the homogeneity and density inside the green body, respectively obtaining a flaky microwave dielectric ceramic sample and a cylindrical microwave dielectric ceramic sample. Keep the flaky microwave dielectric ceramic sample and the cylindrical microwave dielectric ceramic sample at 500 °C for 3 h for debinding, and sinter at 1200 °C for 4 h to obtain a flaky microwave dielectric ceramic and a cylindrical microwave dielectric ceramic, which are respectively used for testing microwave dielectric properties and thermal expansion properties.

[0088] Figure 2 SEM image of the microwave dielectric ceramic prepared in Example 1 of this application.

[0089] Example 2

[0090] This application example provides a microwave dielectric ceramic material and its preparation method, which includes the following steps:

[0091] S1. Preparation of pre-sintered material

[0092] Mix BaCO3, SrCO3, and WO3 according to the chemical formula Sr 0.8 Ba 0.2 WO4, where the molar ratio of BaCO3, SrCO3, and WO3 is 0.2:0.8:1. Then put the prepared raw materials into a ball milling tank, and add zirconia balls and absolute ethanol to the ball milling tank. The mass ratio of the raw materials, zirconia balls, and absolute ethanol is 1:1.5:2. After sealing, place it in a planetary ball mill and ball mill at a speed of 500 r / min for 8 h. After completing the ball milling, take out the raw materials, dry them at 120 °C to volatilize the absolute ethanol, then sieve through 140 mesh, and then evenly spread the sieved raw material powder in a crucible and pre-sinter at 900 °C for 4 h to obtain the pre-sintered material.

[0093] S2. Prepare microwave dielectric ceramic materials

[0094] Pound and grind the prepared pre-sintered material finely, then put it into a ball milling tank, and add zirconia balls and absolute ethanol to the ball milling tank. The mass ratio of the pre-sintered material, zirconia balls, and absolute ethanol is 1:1.5:2. After sealing, place it in a planetary ball mill and ball mill at a speed of 500 r / min for 4 h. After completing the ball milling, take out the pre-sintered material, dry it at 120 °C to volatilize the absolute ethanol, then sieve through 120 mesh and 60 mesh in sequence, and then mix the sieved pre-sintered material with a 5 wt% aqueous solution of polyvinyl alcohol for granulation. The mass of the aqueous solution of polyvinyl alcohol is 10 wt% of the mass of the pre-sintered material. The granulated pre-sintered material is respectively formed by uniaxial pressing using a mold and a mold at a pressure of 150 MPa, and cold isostatically pressed at a pressure of 250 MPa to improve the internal uniformity and density of the green body, respectively obtaining a flaky microwave dielectric ceramic sample and a cylindrical microwave dielectric ceramic sample. The flaky microwave dielectric ceramic sample and the cylindrical microwave dielectric ceramic sample are both degummed by holding at 500 °C for 3 h and sintered at 1050 °C for 4 h to obtain a flaky microwave dielectric ceramic and a cylindrical microwave dielectric ceramic, which are respectively used for testing microwave dielectric properties and thermal expansion properties.

[0095] Example 3

[0096] This application example provides a microwave dielectric ceramic material and its preparation method, which includes the following steps:

[0097] S1. Prepare pre-sintered material

[0098] Mix CaCO3, BaCO3, and MoO3 according to the chemical formula Ba 09 Ca 01Prepare MoO4, where the molar ratio of CaCO3, BaCO3, and MoO3 is 0.1:0.9:1. Then put the prepared raw materials into a ball milling tank, and add zirconia balls and absolute ethanol to the ball milling tank. The mass ratio of the raw materials, zirconia balls, and absolute ethanol is 1:1.5:2. After sealing, place it in a planetary ball mill and ball mill at a speed of 500 r / min for 8 h. After the ball milling is completed, take out the raw materials, dry them at 120 °C to volatilize the absolute ethanol, then screen them through 140 meshes, and then evenly spread the sieved raw material powder in a crucible and pre-sinter it at a temperature of 900 °C for 4 h to obtain a pre-sintered material.

[0099] S2. Prepare microwave dielectric ceramic materials

[0100] Pound and grind the obtained pre-sintered material finely, then put it into a ball milling tank, and add zirconia balls and absolute ethanol to the ball milling tank. The mass ratio of the pre-sintered material, zirconia balls, and absolute ethanol is 1:1.5:2. After sealing, place it in a planetary ball mill and ball mill at a speed of 500 r / min for 4 h. After the ball milling is completed, take out the pre-sintered material, dry it at 120 °C to volatilize the absolute ethanol, then screen it through 120 meshes and 60 meshes in sequence, and then mix the sieved pre-sintered material with a 5 wt% aqueous solution of polyvinyl alcohol for granulation. The mass of the aqueous solution of polyvinyl alcohol is 10 wt% of the mass of the pre-sintered material. The granulated pre-sintered material is respectively filled with molds and molds, and uniaxially pressed at a pressure of 150 MPa for forming, and cold isostatically pressed at a pressure of 250 MPa to improve the uniformity and density inside the green body, respectively obtaining a flaky microwave dielectric ceramic sample and a cylindrical microwave dielectric ceramic sample. Both the flaky microwave dielectric ceramic sample and the cylindrical microwave dielectric ceramic sample are kept at 500 °C for 3 h for debinding, and sintered at 1050 °C for 4 h to obtain a flaky microwave dielectric ceramic and a cylindrical microwave dielectric ceramic, which are respectively used for testing microwave dielectric properties and thermal expansion properties.

[0101] Example 4

[0102] The embodiment of the present application provides a microwave dielectric ceramic material and a preparation method thereof, which include the following steps:

[0103] S1. Prepare a pre-sintered material

[0104] ZnO and SiO₂ are configured according to the chemical formula Zn₂SiO₄, where the molar ratio of ZnO to SiO₂ is 0.8:1.2:1. Then the prepared raw materials are put into a ball milling tank, and zirconia balls and absolute ethanol are added to the ball milling tank. The mass ratio of the raw materials, zirconia balls and absolute ethanol is 1:1.5:2. After sealing, it is placed in a planetary ball mill and ball milled at a speed of 500 r / min for 8 h. After the ball milling is completed, the raw materials are taken out and dried at 120 °C to volatilize the absolute ethanol, then sieved through 140 meshes, and then the sieved raw material powder is evenly spread in a crucible and pre-sintered at a temperature of 1100 °C for 4 h to obtain a pre-sintered material.

[0105] S2. Preparation of microwave dielectric ceramic materials

[0106] The obtained pre-sintered material is crushed and ground fine, and then put into a ball milling tank, and zirconia balls and absolute ethanol are added to the ball milling tank. The mass ratio of the pre-sintered material, zirconia balls and absolute ethanol is 1:1.5:2. After sealing, it is placed in a planetary ball mill and ball milled at a speed of 500 r / min for 4 h. After the ball milling is completed, the pre-sintered material is taken out and dried at 120 °C to volatilize the absolute ethanol, and then sieved through 120 meshes and 60 meshes in sequence. Then the sieved pre-sintered material is mixed with a 5 wt% aqueous solution of polyvinyl alcohol for granulation. The mass of the aqueous solution of polyvinyl alcohol is 10 wt% of the mass of the pre-sintered material. The granulated pre-sintered material is respectively filled with molds and molds, and uniaxially pressed at a pressure of 150 MPa for forming, and cold isostatically pressed at a pressure of 250 MPa to improve the internal uniformity and density of the green body, and a flaky microwave dielectric ceramic sample and a cylindrical microwave dielectric ceramic sample are respectively obtained. The flaky microwave dielectric ceramic sample and the cylindrical microwave dielectric ceramic sample are both kept at 500 °C for 3 h for debinding, and sintered at 1250 °C for 4 h to obtain a flaky microwave dielectric ceramic and a cylindrical microwave dielectric ceramic, which are respectively used for testing microwave dielectric properties and thermal expansion properties.

[0107] Example 5

[0108] The embodiment of the present application provides a microwave dielectric ceramic material and a preparation method thereof, which include the following steps:

[0109] S1. Preparation of pre-sintered material

[0110] ZnO and SiO₂ were configured according to the chemical formula Zn₂SiO₄, where the molar ratio of ZnO to SiO₂ was 0.8:1.2:1. Then, the prepared raw materials were put into a ball milling tank, and zirconia balls and absolute ethanol were added to the ball milling tank. The mass ratio of the raw materials, zirconia balls, and absolute ethanol was 1:1.5:2. After sealing, it was placed in a planetary ball mill and ball milled at a speed of 500 r / min for 8 h. After the ball milling was completed, the raw materials were taken out, dried at 120 °C to volatilize the absolute ethanol, then sieved through 140 mesh, and then the sieved raw material powder was evenly spread in a crucible and pre-sintered at a temperature of 1100 °C for 4 h to obtain a pre-sintered material.

[0111] S2. Adding sintering aids

[0112] After the obtained pre-sintered material was crushed and ground, the main Zn₂SiO₄ material and the sintering aid B₂O₃ were accurately weighed according to the formula. The molar percentage of the main Zn₂SiO₄ material was 75 mol.%, and the molar percentage of B₂O₃ was 25 mol.%.

[0113] S3. Preparing microwave dielectric ceramic materials

[0114] The powder prepared in S2 was put back into the ball milling tank, and zirconia balls and absolute ethanol were added to the ball milling tank. The mass ratio of the pre-sintered material, zirconia balls, and absolute ethanol was 1:1.5:2. After sealing, it was placed in a planetary ball mill and ball milled at a speed of 500 r / min for 4 h. After the ball milling was completed, it was taken out and dried at 120 °C to volatilize the absolute ethanol, then sieved through 120 mesh and 60 mesh in sequence, and then the sieved pre-sintered material was mixed with a 5 wt% aqueous solution of polyvinyl alcohol for granulation. The mass of the aqueous solution of polyvinyl alcohol was 10 wt% of the mass of the pre-sintered material. The granulated pre-sintered material was respectively formed by molds and molds, and uniaxially pressed at a pressure of 150 MPa for forming, and cold isostatically pressed at a pressure of 250 MPa to improve the homogeneity and density inside the green body, respectively obtaining a flaky microwave dielectric ceramic sample and a cylindrical microwave dielectric ceramic sample. The flaky microwave dielectric ceramic sample and the cylindrical microwave dielectric ceramic sample were both kept at 500 °C for 3 h for debinding, and sintered at 800 °C for 4 h to obtain a flaky microwave dielectric ceramic and a cylindrical microwave dielectric ceramic, which were respectively used for testing microwave dielectric properties and thermal expansion properties.

[0115] The parameters of Examples 1 to 5 are shown in Table 1.

[0116] Table 1 Parameters of Examples 1 to 5

[0117]

[0118] Example 6

[0119] An embodiment of the present application provides a three-dimensional multi-layer packaging module. The three-dimensional multi-layer packaging module includes an integrated circuit chip, a three-dimensional multi-layer interposer substrate, and a PCB carrier board arranged in sequence along the height direction. The three-dimensional multi-layer interposer substrate includes 2 ceramic structures. The thermal expansion coefficient of the integrated circuit chip is 2.8 ppm / °C, the thermal expansion coefficient of the ceramic structure of the PCB carrier board is 12 ppm / °C, the thermal expansion coefficient of the ceramic structure combined with the integrated circuit chip is 2.8 ppm / °C, and the thermal expansion coefficient of the ceramic structure combined with the PCB carrier board is 11.5 ppm / °C.

[0120] Example 7

[0121] An embodiment of the present application provides a three-dimensional multi-layer packaging module. The three-dimensional multi-layer packaging module includes an integrated circuit chip, a three-dimensional multi-layer interposer substrate, and a PCB carrier board arranged in sequence along the height direction. The three-dimensional multi-layer interposer substrate includes 10 ceramic structures. The thermal expansion coefficient of the integrated circuit chip is 2.8 ppm / °C, the thermal expansion coefficient of the ceramic structure of the PCB carrier board is 14 ppm / °C, the thermal expansion coefficient of the ceramic structure combined with the integrated circuit chip is 3.0 ppm / °C, the thermal expansion coefficient of the ceramic structure combined with the PCB carrier board is 12 ppm / °C, and the thermal expansion coefficient difference between any two adjacent ceramic structures is 0 to 5 ppm / °C.

[0122] Example 8

[0123] An embodiment of the present application provides a three-dimensional multi-layer packaging module. The three-dimensional multi-layer packaging module includes an integrated circuit chip, a three-dimensional multi-layer interposer substrate, and a PCB carrier board arranged in sequence along the height direction. The three-dimensional multi-layer interposer substrate includes 100 ceramic structures. The thermal expansion coefficient of the integrated circuit chip is 3.5 ppm / °C, the thermal expansion coefficient of the ceramic structure of the PCB carrier board is 15 ppm / °C, the thermal expansion coefficient of the ceramic structure combined with the integrated circuit chip is 3.2 ppm / °C, the thermal expansion coefficient of the ceramic structure combined with the PCB carrier board is 14 ppm / °C, and the thermal expansion coefficient difference between any two adjacent ceramic structures is 0 to 5 ppm / °C.

[0124] Example 9

[0125] The present application provides a method for preparing a three-dimensional multi-layer interposer substrate, which includes the following steps:

[0126] According to the gradient transformation of the thermal expansion coefficient from low to high, 10 layers of each material are selected. That is, for the upper 10 layers, materials with a lower thermal expansion coefficient such as (Ca 0.5 Mg 0.5 )2SiO4 are selected, for the middle 10 layers, materials with a medium thermal expansion coefficient such as Ba 0.9 Ca 0.1 MoO4 are selected, and for the lower 10 layers, materials with a higher thermal expansion coefficient such as Sr 0.8Ba 0.2 WO4. The green body of the multilayer microwave dielectric ceramic is obtained by using the multilayer ceramic preparation process.

[0127] The green body of the multilayer microwave dielectric ceramic is heated to 500 °C at a rate of 3 °C / min and held for 12 h for debinding. Then it is continuously heated to 1200 °C at a rate of 3 °C / min and held for 2 h. Then it is cooled to 1000 °C at a rate of 2 °C / min and held for 2 h, and then cooled with the furnace. Finally, a multilayer microwave dielectric ceramic with a gradient change in thermal expansion coefficient is obtained, solving the warping and thermal stress problems caused by the difference in thermal expansion coefficient, while maintaining a high-quality interlayer bond.

[0128] The SEM image of the prepared heterogeneous multilayer microwave dielectric ceramic is as Figure 3 shown.

[0129] Test Example 1

[0130] The relative dielectric constant (ε r ), quality factor (Q×f), resonant frequency temperature coefficient (TCF), and thermal expansion coefficient (CTE) of the microwave dielectric ceramic materials prepared in Examples 1 to 5 were measured respectively, and the results are shown in Table 2.

[0131] The test method is as follows:

[0132] The test equipment includes a network analyzer (E5227B, Keysight, American), a dilatometer (DIL402Expedis Classoic, NETZSCH, German), and a temperature control box (CORP / SH-222, ESPEC, Japan). The microwave dielectric properties and temperature spectrum of the samples were measured by the closed cavity resonance method. The calculation formula of TCF is as follows:

[0133]

[0134] f 85 and f 25 are the resonant frequencies in the TE 01δ mode at 85 °C and 25 °C respectively. The CTE of the samples was measured by the thermal expansion method.

[0135] The thermal expansion method (Dilatometry, abbreviated as DIL) is to control the sample under a certain temperature program (heating / cooling / constant temperature and their combinations), and measure the change process of the length of the sample in the test direction with temperature or time under the condition that the load force can be ignored. By calculating the average length change rate of the sample per unit length in a certain temperature range (T1, T2), the CTE of the sample is finally obtained. The calculation formula of CTE is as follows:

[0136] α(T1 - T2) = [(ΔL / L0) (T2)-(ΔL / L0) (T1) / (T2 - T1)

[0137] where L0 represents the initial length of the sample at room temperature, and (ΔL / L0) (T) represents the length change rate of the sample at temperature T.

[0138] Table 2 Optimal properties of the microwave dielectric ceramic materials prepared in Examples 1 - 5

[0139]

[0140] As can be seen from Table 2, the thermal expansion coefficient of the microwave dielectric ceramic material of the present application can be adjusted between -5 ppm / °C and 15 ppm / °C, while meeting the relative dielectric constant of 5.5 - 12.5, the quality factor of 3000 GHz - 300000 GHz, and the temperature coefficient of resonant frequency of -100 ppm / °C to +30 ppm / °C.

[0141] The above are only specific embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A microwave dielectric ceramic material with continuously adjustable thermal expansion coefficient, characterized in that, The chemical formula of the microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion is A 1-x B x D y O z ; Wherein, A and B are each independently selected from any one or more of Zn, Mg, Ca, Sr, Ba, Fe, Co, Ni, and Cu, x is from 0 to 1, and the elements selected for A and B are different; D is selected from W, Mo, Si, Ge, Sn, Se, V, Bi, or S.

2. The microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion according to claim 1, characterized in that Said A and B are each independently selected from Zn, Mg, Ca, Sr, Ba, Fe, Co, Ni, or Cu.

3. The microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion according to claim 1, characterized in that, The microwave dielectric ceramic material satisfies the following conditions: a. The relative dielectric constant is 5.5 to 12.5; b. The quality factor is 3000 GHz to 300000 GHz; c. The resonant frequency temperature coefficient is -100 ppm / °C to +30 ppm / °C; d. The thermal expansion coefficient is -5 ppm / °C to 15 ppm / °C.

4. A method for preparing a microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion according to any one of claims 1 to 3, characterized in that, The preparation method includes: pre-sintering the raw materials at a temperature of 1000°C to 1250°C for 1 h to 24 h to obtain a pre-sintered material, then granulating and pressing the pre-sintered material into a shape, and then sequentially degumming at a temperature of 300°C to 600°C for 2 h to 12 h and sintering at a temperature of 800°C to 1700°C for 1 h to 24 h to obtain the microwave dielectric ceramic material; The raw materials include oxides or salts of element A, element B, and element D.

5. The preparation method of the microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion according to claim 4, characterized in that, Before pre-sintering the raw materials, first perform a first ball milling treatment on the raw materials, and sieve through 140 meshes after drying.

6. The preparation method of the microwave dielectric ceramic material with continuously adjustable coefficient of thermal expansion according to claim 4, characterized in that Before granulating the pre-sintered material, first perform a second ball milling treatment on the pre-sintered material, and sequentially sieve through 120 meshes and 60 meshes after drying.

7. A three-dimensional multi-layer interposer substrate, characterized in that, The three-dimensional multi-layer transfer substrate includes a multi-layer ceramic structure and a vertical interconnection structure arranged in layers along the thickness direction. The multi-layer ceramic structure has a chip connection port for electrically connecting with an integrated circuit chip and a PCB connection port for electrically connecting with a PCB carrier board. Electrical connection between the multi-layer ceramic structures is achieved through the vertical interconnection structure; Each layer of the ceramic structure includes a main body and an interconnection circuit. The main body includes the microwave dielectric ceramic material with continuously adjustable thermal expansion coefficient according to any one of claims 1 to 3. The thermal expansion coefficient of the multi-layer ceramic structure increases along the thickness direction. The interconnection circuit is distributed on the surface and / or inside of the main body.

8. A three-dimensional multi-layer packaging module, characterized in that The three-dimensional multi-layer packaging module includes an integrated circuit chip, the three-dimensional multi-layer transfer substrate according to claim 7, and a PCB carrier board arranged in sequence along the height direction. The thermal expansion coefficient of the integrated circuit chip is less than the thermal expansion coefficient of the PCB carrier board. The difference between the thermal expansion coefficient of the ceramic structure combined with the integrated circuit chip and the thermal expansion coefficient of the integrated circuit chip is 0 to 5 ppm / °C, and the difference between the thermal expansion coefficient of the ceramic structure combined with the PCB carrier board and the thermal expansion coefficient of the PCB carrier board is 0 to 5 ppm / °C.

9. The three-dimensional multi-layer packaging module according to claim 8, wherein The number of layers of the three-dimensional multi-layer transfer substrate is 2 to 100 layers.

10. The three-dimensional multi-layer packaging module according to claim 8, wherein, The difference in thermal expansion coefficient between any two adjacent layers of the ceramic structure in the three-dimensional multi-layer transfer substrate is 0 to 5 ppm / °C.

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