A CNC high-precision high-temperature-resistant insulating bottom plate engraving and tin-copper alloy printed circuit 3D printing combined manufacturing method

Abstract

This invention discloses a method for combining CNC high-precision high-temperature resistant insulating substrate engraving with tin-copper alloy printed circuit 3D printing, belonging to the field of high-power circuit carrier manufacturing technology. The invention uses 99.7% alumina ceramic or silicon nitride ceramic as the insulating substrate, achieving high-precision structural forming of ±0.005-0.025mm through CNC layer engraving. Sandblasting, roughening, sensitization, activation, and pre-plating surface modification enhance interfacial adhesion. CuSn10 tin bronze is used as the printing material, and the circuit is formed by SLM or FDM 3D printing at a sintering temperature of 850-900℃, achieving a forming density ≥98.71%. Through stepped heating sintering and high-temperature resistant inorganic adhesive curing, the ceramic substrate and tin-copper alloy circuit are integrated. The circuit carrier obtained by this invention has a long-term temperature resistance of ≥1600℃, a volume resistivity of ≥10¹⁴Ω·cm, a current carrying capacity of 15.6A for 3mm lines, and an adhesion strength retention rate of ≥95% after 1000 thermal cycles. The temperature rise is 15~20℃ lower than that of traditional PCBs. It is suitable for high-load, high-current scenarios such as industrial power supplies and new energy power control. It is compatible with processes and has complete industrial support, and has significant technical and economic feasibility.

Description

Technical Field

[0001] This invention relates to high-power power electronic circuit carrier manufacturing technology, and more particularly to a combined manufacturing technology of CNC high-precision high-temperature resistant insulating base plate engraving and tin-copper alloy printed circuit 3D printing, which is applicable to high-current, high-temperature resistant, and high-reliability scenarios such as industrial power supplies, new energy power controls, and aerospace power supplies. Background Technology

[0002] Traditional organic substrate PCBs such as FR-4 have a heat resistance below 200℃, and are prone to carbonization and insulation failure at high temperatures; the screen printing process limits the line width and current carrying capacity, and large currents can easily cause overheating and melting; the planar structure cannot be adapted to irregular integration, and the adapter increases parasitic parameters and failure risks.

[0003] Tin-copper alloy 3D printing can achieve high-current, thick-circuit molding. Ceramic substrates are resistant to high temperatures, have high insulation, and low deformation. However, the poor bonding between ceramics and metals, thermal expansion mismatch, and insufficient process compatibility limit integrated applications.

[0004] Existing technologies lack complete solutions for high-precision engraving, interface modification, temperature matching, and precision coordination, and cannot meet the requirements for long-term stable operation in industrial applications. Summary of the Invention

[0005] Overcoming the shortcomings of traditional PCBs such as poor heat resistance, low current carrying capacity, and insufficient reliability, this paper provides a method for the integrated manufacturing of ceramic substrate-tin-copper alloy circuits that is resistant to high temperatures, high current, highly stable, and compatible with various processes.

[0006] A method for combining CNC high-precision high-temperature resistant insulating base plate engraving with tin-copper alloy printed circuit 3D printing, comprising:

[0007] The preferred material is 99.7% alumina ceramic, with a long-term temperature resistance of ≥1600℃ and a volume resistivity of ≥10¹. 4 Ω·cm; three-step layered engraving with an accuracy of ±0.005~0.025mm and a surface Ra≤0.15μm.

[0008] Sandblasting roughening → stannous chloride sensitization → palladium chloride activation significantly improve the bonding strength between ceramics and alloys.

[0009] SLM green laser printing achieves a density of ≥98.71%; FDM printing is followed by sintering at 850~900℃, making it suitable for small-batch, low-cost manufacturing.

[0010] Controlling the heating rate releases thermal stress, and using ultra-high temperature inorganic adhesives achieves long-term stable bonding.

[0011] Heat resistance: The ceramic substrate has a long-term temperature resistance of ≥1600℃ and meets the requirement of no deformation or cracking when sintered at 850~900℃; High current: 15.6A current carrying capacity for a 3mm² line, with a temperature rise reduction of 15~20℃; High reliability: Strength retention rate ≥95% after 1000 thermal cycles, stable insulation; Process compatibility: CNC and 3D printing precision are matched, making it feasible for industrialization in the Pearl River Delta; Cost advantage: Small batch production eliminates the need for molds, and mass production costs are lower than traditional thick copper PCBs. Detailed Implementation

[0012] Material: 99.7% alumina ceramic, 1mm thick; CNC engraving: roughing → semi-finishing → finishing, accuracy ±0.01mm, Ra≤0.12μm; Surface modification: 120 mesh alumina sandblasting at 0.25 MPa → SnCl2 sensitization for 12 min → PdCl2 activation for 6 min; 3D printing: Green laser SLM, power 180W, scanning speed 400mm / s, layer thickness 0.04mm; Sintering: Stepwise heating to 880℃ and holding for 5 hours; Curing: HN-978 inorganic adhesive undergoes step curing and is cooled to room temperature.

[0013] Performance: 15.6A / 3mm current carrying capacity, 96% strength retention after 1000 thermal cycles, and no insulation degradation at 500℃.

[0014] Material: Silicon nitride ceramic, 0.8mm thick; CNC engraving: accuracy ±0.02mm; Surface modification is the same as in Example 1; FDM printing: layer thickness 0.3mm, sintering 900℃ / 5h; Bonding and curing: THO4055 high-temperature epoxy adhesive is cured.

[0015] Performance: Excellent heat dissipation, vibration and shock resistant, suitable for extreme vehicle operating conditions.

[0016] Engraving precision: ±0.005~0.025mm Sintering temperature: 850~900℃ Laser power: 160~200W Heating rate: 3~10℃ / min Adhesion strength retention rate: ≥95% Current carrying capacity: ≥15.6A with 3mm linewidth

[0017] This method can achieve full-chain support in the Pearl River Delta and is applicable to industrial power supplies, new energy vehicle electronic control systems, satellite power supplies, and high-power power electronic equipment. It is an upgrade and replacement solution for traditional PCBs.

Claims

1. A method for combining CNC high-precision high-temperature resistant insulating base plate engraving with tin-copper alloy printed circuit 3D printing, characterized in that, Includes the following steps: High-temperature resistant insulating base plate material selection and CNC high-precision layer engraving: Alumina ceramic or silicon nitride ceramic is selected as the base plate, and diamond tools are used to perform three-step layer engraving: roughing, semi-finishing and finishing. The processing accuracy is ±0.005~0.025mm and the surface roughness Ra≤0.15μm. Substrate surface modification treatment: sequentially undergoing sandblasting roughening, sensitization treatment, and activation treatment to improve the surface roughness and active sites of the ceramic. 3D printing of tin-copper alloy circuits: Using CuSn10 tin bronze as the material, circuit lines are printed using SLM or FDM processes, with a line width tolerance of ±0.05~0.1mm; Step-by-step heating sintering and curing: The temperature is increased to 850~900℃ in steps and held for sintering to achieve an alloy density of ≥98.71%; high-temperature resistant inorganic adhesive is used for bonding and curing to complete the integrated molding.

2. The combined manufacturing method according to claim 1, characterized in that, The alumina ceramic is 99.7% high-purity alumina, with a long-term operating temperature ≥1600℃ and a volume resistivity ≥10¹ at 500℃. 4 Ω·cm; thermal conductivity of silicon nitride ceramic is 80~100W / m·K, and flexural strength is ≥800MPa.

3. The combined manufacturing method according to claim 1, characterized in that, The CNC layer engraving parameters are as follows: roughing is performed using a diamond-coated end mill with a cutting speed of 90 km / h. 120m / min, depth of cut 1.2 1.8mm / layer; semi-finishing is performed using a diamond ball end mill with a cutting speed of 100. 130m / min, depth of cut 0.1 0.2mm / layer; finishing is done with a diamond micro-end mill at a cutting speed of 120. 150m / min, depth of cut 0.08 0.12mm / layer.

4. The combined manufacturing method according to claim 1, characterized in that, The surface modification treatment is: 100 150 mesh 0.2g of alumina abrasive 0.3MPa sandblasting to Ra=3 5μm; 0.1 mol / L stannous chloride solution 25 Sensitization at 30℃10 15min; 0.05 mol / L palladium chloride solution 25 Activate at 30℃ for 5~8 minutes.

5. The combined manufacturing method according to claim 1, characterized in that, SLM printing parameters: Green laser power 160 200W, scan speed 300 500mm / s, line spacing 0.07 0.1mm, layer thickness 0.03 0.05mm; the FDM printing sintering temperature is 850~900℃, and the holding time is 5h.

6. The combined manufacturing method according to claim 1, characterized in that, The stepped heating regime is as follows: room temperature → 300℃ (10℃ / min) for 2 hours → 500℃ (5℃ / min) for 2 hours → 850~900℃ (3℃ / min) for 5 hours, followed by furnace cooling.

7. The combined manufacturing method according to claim 1, characterized in that, The high-temperature resistant inorganic adhesive is HN-978, with a long-term temperature resistance of 1730℃ and a volume resistivity ≥10¹ after curing. 4 Ω·cm, bonding strength ≥10MPa; curing process: room temperature pre-curing → 80℃ medium temperature curing → 150℃ high temperature curing → slow cooling.

8. The combined manufacturing method according to claim 1, characterized in that, The resulting circuit carrier has a current carrying capacity of 15.6A for 3mm lines, and its strength retention rate is ≥95% after 1000 thermal cycles. The temperature rise is 15~20℃ lower than that of traditional screen-printed PCBs.

9. An industrial-grade high-current, high-temperature resistant circuit carrier prepared by the method described in any one of claims 1-8, characterized in that, With ceramic as the insulating base and CuSn10 tin bronze as the conductive circuit, it is integrated in one piece. It has a long-term temperature resistance of ≥454℃ and an instantaneous temperature resistance of ≥900℃, and is suitable for industrial power supplies, new energy power control, and high-power power electronic equipment.

10. The circuit carrier according to claim 9, characterized in that, The ceramic base plate and the tin-copper alloy circuit are bonded together with inorganic adhesive after surface modification. The interface is free from cracking and peeling, and the insulation performance and mechanical strength meet the requirements for long-term stable operation in industrial applications.