Method for manufacturing high-precision multilayer ceramic circuit board

Abstract

The invention belongs to the technical field of ceramics, and particularly relates to a manufacturing method of a high-precision multilayer ceramic circuit board. The preparation method comprises the following specific steps: S1, material preparation: preparing a ceramic material into a raw material belt by adopting a tape casting method, and preparing conductor paste by using metal powder; s2, slurry printing: full-width conductor slurry is printed on a raw material belt by adopting a thick film silk-screen printing method, and a printed pattern is manufactured; s3, circuit preparation: according to the requirements of a circuit in a design drawing, a laser micro-etching method is adopted to manufacture the circuit with the line width of 20-50 microns / the line spacing of 20-50 microns on the raw material belt printed with the pattern; and S4, stacking a plurality of raw material belts after circuit manufacturing, placing the stacked raw material belts in warm water for isostatic pressing to form a multilayer ceramic circuit board green body, and then sintering to prepare the multilayer ceramic circuit board. According to the invention, the high-precision multilayer ceramic circuit board can be manufactured, and the manufacturing cost is reduced; the method is high in efficiency and simple in process, and promotes the development of the device to the high-frequency and high-speed application field.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramics, and in particular relates to a method for manufacturing a high-precision multilayer ceramic circuit board. Background Art

[0002] With the development of optical communication, microwave radio frequency and other communication technologies, the future will mainly develop in the direction of high frequency, high speed, high integration, miniaturization, high reliability, high precision, etc. The current traditional circuit boards such as PCB can no longer meet their application development needs. Due to the advantages of high thermal conductivity, high stability, low dielectric loss, high insulation and other advantages of ceramic materials, multilayer ceramic circuit boards have gradually become the representative direction of the next generation of circuit boards in the future.

[0003] There are two main methods for preparing mainstream ceramic circuit boards, namely thick film screen printing and thin film photolithography. Among them, the thick film screen printing method is to spread the conductive paste on the stainless steel or polyester screen with different parameters, use the scraper under a certain pressure, and use different printing parameters to prepare the ceramic circuit board. Due to the limitations of the screen mesh and latex thickness of the production materials and the resolution of the fine lines of the paste, it is impossible to produce high-precision line width and line spacing multilayer circuit boards, and can only produce circuit boards with a line width / line spacing of more than 50μm; while the ceramic circuit board with higher precision uses the thin film photolithography method to prepare the circuit board with a line width of 20μm / 20μm line spacing, and uses sputtering, photolithography, photosensitive glue, exposure, development and other similar thin film processes to prepare metal circuits, which requires the use of high-priced and high-precision equipment, the process is complicated, and the pattern spacing can only be made on the upper and lower surfaces. Summary of the invention

[0004] In order to overcome the defects in the prior art, the present invention provides a method for manufacturing a high-precision multilayer ceramic circuit board. The present invention can manufacture a high-precision multilayer ceramic circuit board and reduce the manufacturing cost.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for manufacturing a high-precision multilayer ceramic circuit board, the specific steps are as follows:

[0007] S1. Material preparation: Ceramic material is made into raw tape by tape casting method, and conductor slurry is prepared by metal powder;

[0008] S2, slurry printing: using thick film screen printing method to print full width of conductor slurry on raw tape to produce printed graphics;

[0009] S3. Circuit preparation: According to the circuit requirements in the design drawings, a circuit with a line width of 20-50 μm / line spacing of 20-50 μm is made on the raw tape after the pattern is printed by laser micro-etching;

[0010] S4, stacking several raw tapes after circuit making, placing them in warm water for isostatic pressing to form a multi-layer ceramic circuit board green body, and then sintering to prepare a multi-layer ceramic circuit board.

[0011] Preferably, in step S1, the ceramic material is one of alumina, aluminum nitride, silicon nitride, mullite, zirconium oxide, and glass ceramics. The raw materials of the circuit board can be prepared from other materials according to actual needs.

[0012] Preferably, in step S1, the size of the raw tape is 101.6×101.6 mm to 203.2 mm×203.2 mm, and the thickness is 0.05 to 1.0 mm.

[0013] Preferably, in step S1, the metal powder is micron-sized metal powder.

[0014] Preferably, in step S1, the metal powder is one of Ag, Au, W, Mo, MnMo and Ni.

[0015] Preferably, the conductive paste has a viscosity of 30-500 PaS and a solid content of 75-85%.

[0016] Preferably, in step S2, the printing thickness of the printed pattern is 5 to 30 μm.

[0017] Preferably, in step S3, the laser used in the laser micro-etching method is one of a nanosecond laser, a picosecond laser and a femtosecond laser.

[0018] Preferably, in step S3, the laser spot of the laser micro-etching method used is ≤10 μm, and the laser energy is ≤15 W.

[0019] Preferably, in step S4, the temperature of the warm water is 40-80°C; and the sintering temperature is 800-1900°C.

[0020] The advantages of the present invention are:

[0021] (1) The present invention introduces a laser micro-etching method for the first time in the multi-layer ceramic high-precision circuit board preparation industry to prepare high-precision ceramic circuit boards. This method can not only prepare circuit boards with wide spacing and large line width, but also can produce high-precision (i.e., line width <50μm and / or line spacing <50μm) circuit boards. The method is simple and easy to implement, meets the development needs of communication technologies such as optical communication and microwave radio frequency, improves the preparation level of multi-layer ceramic circuit boards, and is environmentally friendly and pollution-free.

[0022] (2) The high-precision circuit board prepared by the present invention has a small line width and a small line spacing, which can improve the system integration and transmission rate to meet the future application scenarios of miniaturization and intelligence. In addition, the preparation method is efficient and the process is simple, which can effectively promote the development of devices towards high-frequency and high-speed applications, and provide a feasible solution for the large-scale promotion of 6G or 1.6Tbps.

[0023] (3) The circuit board produced by the present invention can not only produce high-precision line width and line spacing patterns on the upper and lower surfaces, but also because the circuit board of the present invention is stacked by multiple raw tapes etched with circuits, the inside of the circuit board prepared by the present invention can also produce high-precision line width and line spacing patterns, so that the circuit board has a higher degree of integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the design pattern of line width (20-50 μm) / line spacing (20-50 μm) of Example 1 of the present invention.

[0025] Figure 2 for Figure 1 A partial enlarged view of .

[0026] Figure 3 This is a picture of a raw tape with a line width of 20 μm and a line spacing of 20 μm prepared in the present invention under a microscope.

[0027] Figure 4 for Figure 3 A magnified image of a 20μm line spacing raw tape tested using optical testing equipment.

[0028] Figure 5 for Figure 3 A magnified image of the 20μm line width / 20μm line spacing raw tape tested using optical testing equipment.

[0029] Figure 6 This is a picture of the raw tape with 30 μm line width / 30 μm line spacing prepared in the present invention under a microscope.

[0030] Figure 7 for Figure 6 A magnified image of a 30μm line spacing raw tape tested using optical testing equipment.

[0031] Figure 8 for Figure 6 A magnified image of the 30μm line width / 30μm line spacing raw tape tested using optical testing equipment.

[0032] Fig. 9 This is a picture of the raw tape with 40 μm line width / 40 μm line spacing prepared in the present invention under a microscope.

[0033] Fig.10for Fig. 9 A magnified image of the 40μm line spacing raw tape tested using optical testing equipment.

[0034] Fig.11 for Fig. 9 A magnified image of the 40μm line width / 40μm line spacing raw tape tested using optical testing equipment.

[0035] Fig.12 This is a picture of a raw tape with a line width of 50 μm and a line spacing of 50 μm prepared in the present invention under a microscope.

[0036] Fig.13 for Fig.12 A magnified image of the 50μm line spacing raw tape tested using optical testing equipment.

[0037] Fig.14 for Fig.12 A magnified image of the 50μm line width / 50μm line spacing raw tape tested using optical testing equipment. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0039] A method for manufacturing a high-precision multilayer ceramic circuit board, the steps are as follows:

[0040] S1: According to the design requirements, ceramic raw tapes of different materials, sizes and thicknesses are manufactured, preferably ceramic raw tapes of 4in×4in~8in×8in (101.6×101.6mm~203.2mm×203.2mm) in size and 0.05~1.0mm in thickness;

[0041] S2: Use micron-sized Ag / Au / Mo / W and other metal powders to prepare the conductor slurry, the viscosity of the conductor slurry is 30-500 Pa S, and the solid content is 75-85%;

[0042] S3: Use thick film screen printing to make full-width printed graphics on the raw tape, with a printing thickness of 5 to 30 μm;

[0043] S4: According to the requirements of the circuit board in the design drawings, the printed graphics are made into high-precision (20-50μm) line width / line spacing raw tape by laser micro-etching method, and the laser spot is ≤10μm and the laser energy is ≤15W.

[0044] The raw tapes after steps S1 to S4 are stacked in multiple layers, placed in warm water at 40 to 80° C. and isostatically pressed to form a multi-layer ceramic circuit board green body, and then sintered (800-1900° C.) to prepare a multi-layer ceramic circuit board.

[0045] Example 1

[0046] Step 1: Prepare 8-inch alumina raw tape with a thickness of 0.2 mm by tape casting;

[0047] Step 2: Using Mo powder to prepare a conductive paste, the conductive paste has a viscosity of 100-200 PaS and a solid content of 85%;

[0048] Step 3: performing processes such as patching, punching, and filling holes on the alumina raw tape prepared in step 1;

[0049] Step 4: Printing a full width of the conductor paste on the alumina raw tape after the hole filling with the conductor paste, with a printing thickness of 5 to 15 μm;

[0050] Step 5: Laser micro-etch the printed raw tape, and the etched circuit design is as follows Figure 1-2 As shown, 15W, 10% laser energy, 100KHz frequency, 400mm / s marking speed were used for scanning second etching, and the accuracy of the raw tape was tested. The specific test numerical results are shown in Figure 3-14 As shown;

[0051] Step 6: Then the multi-layer raw tape is stacked and sintered to produce a multi-layer alumina high-precision ceramic circuit board.

[0052] Depend on Figure 3-5 It can be obtained that the circuit with a line width of 20μm and a line spacing of 20μm can be made on the raw tape; Figure 6-8 It can be obtained that the circuit with 30μm line width and 30μm line spacing can be made on the raw tape; Figure 9-11 It can be obtained that the circuit with a line width of 40μm and a line spacing of 40μm can be made on the raw tape; Figure 12-14 It can be obtained that circuits with a line width of 50μm and a line spacing of 50μm can be made on the raw tape; therefore, the present invention can prepare a ceramic circuit board with a line width of 20-50μm and a line spacing of 20-50μm through a simple manufacturing process, and the manufacturing cost is low. The pattern spacing can be made both inside and outside the circuit board, which greatly improves the accuracy and integration of the circuit board.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a high-precision multilayer ceramic circuit board, characterized in that: The specific steps are as follows: S1. Material preparation: Ceramic material is made into raw tape by tape casting method, and conductor slurry is prepared by metal powder; S2, slurry printing: using thick film screen printing method to print full width of conductor slurry on raw tape to produce printed graphics; S3, circuit preparation: laser micro-etching method is used to make circuits with a line width of 20-50 μm / line spacing of 20-50 μm on the raw tape after the pattern is printed; S4, stacking several raw tapes after circuit making, placing them in warm water for isostatic pressing to form a multi-layer ceramic circuit board green body, and then sintering to prepare a multi-layer ceramic circuit board.

2. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S1, the ceramic material is one of aluminum oxide, aluminum nitride, silicon nitride, mullite, zirconium oxide, and glass ceramics.

3. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S1, the size of the raw tape is 101.6×101.6 mm to 203.2 mm×203.2 mm, and the thickness is 0.05 to 1.0 mm.

4. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S1, the metal powder is micron-sized metal powder.

5. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S1, the metal powder is one of Ag, Au, W, Mo, MnMo and Ni.

6. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: The conductive slurry has a viscosity of 30-500 PaS and a solid content of 75-85%.

7. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S2, the printed pattern has a printing thickness of 5 to 30 μm.

8. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S3, the laser used in the laser micro-etching method is one of a nanosecond laser, a picosecond laser and a femtosecond laser.

9. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S3, the laser spot of the laser micro-etching method is ≤10 μm, and the laser energy is ≤15W.

10. The method for manufacturing a high-precision multilayer ceramic circuit board according to claim 1, characterized in that: In step S4, the temperature of the warm water is 40-80°C; the sintering temperature is 800-1900°C.

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