Chapter 1 Thermal management performance
1. High thermal conductivity and low thermal resistance
The thermal conductivity of aluminum nitride (AlN) ceramics is as high as 170-230W/(m·K), and the thermal conductivity of aluminum oxide (Al₂O₃) ceramic substrates is 20-30W/(m·K), which is significantly better than traditional metal substrates. The thermal conductivity of Gujia Intelligent’s DPC process ceramic substrate reaches 235W/(m·K), and the thermal resistance of a 0.25mm thick ceramic substrate is only 0.14K/W, which effectively reduces the operating temperature of the chip.
2. Thermal expansion coefficient matching and structural stability
The thermal expansion coefficient of AlN ceramics is 4.5×10-6/℃, which is close to that of silicon chips (3×10-6/℃, reducing the risk of thermal stress stratification. The CPGA tube shell integrated heat sink block of Zhongci Electronics, combined with the three-dimensional wiring design, improves the heat dissipation efficiency by 30%, supporting high-power laser packaging.
3. Innovation of efficient heat dissipation structure
Jiangsu Toubo Optoelectronics’ patented technology optimizes the heat transfer path through the air duct structure to achieve rapid heat dissipation.
The optical module ceramic heat sink adopts metal-ceramic brazing packaging, with nickel-gold plating on the surface, supports 40GHz high-frequency signal transmission, and the leakage rate is <1×10-8Pa·m³
4. Extreme environment adaptability
The zirconium oxide (ZrO₂) ceramic shell has a temperature resistance of 600℃ and no cracking after 1,500 thermal cycles. It is suitable for industrial lasers (30W-1000W power) and optical communication device packaging.
5. Low current-carrying temperature rise and high reliability
Under 100A current, the temperature rise of 2mm wide copper body of ceramic substrate is only 5℃. Combined with HTCC process, multi-layer wiring (density 200 lines/cm²) is realized to ensure the long-term stability of optical sensors.
Typical applications:
Optical communication module: HTCC ceramic shell integrates microwave-optical coupling structure and supports 100Gbps optical signal transmission.
High-power laser: AlN substrate provides heat dissipation for fiber lasers and is used in cutting, welding and other scenarios.
Chapter 2 Optical performance
1. Low dielectric loss and high-frequency performance
The dielectric loss of ceramic materials (aluminum oxide, aluminum nitride) is less than 0.002, and the dielectric constant range is between 2.5-10, which significantly reduces the energy loss in high-frequency signal transmission. CQFN ceramic shell supports 40GHz high-frequency signal transmission and is suitable for optical communication modules and microwave device packaging.
2. High refractive index and light transmittance
Transparent ceramics (high refractive index transparent ceramics developed by Zhongke Haoye) have a refractive index of 1.8-2.2 (adjustable) and a Mohs hardness of 7.5-8.5. They have both high light transmittance (transmittance in a specific band>80%) and scratch resistance, and are suitable for AR optical waveguide substrates, laser holographic imaging and other scenarios.
3. Three-dimensional integration and high wiring density
The use of DPC (direct electroplating ceramic) technology can achieve line width/line spacing as low as 30μm, through-hole diameter 60-120μm, support three-dimensional cavity structure packaging, and increase integration by more than 3 times, meeting the miniaturization requirements of optical communication sensors and laser devices.
4. Thermal expansion coefficient matching and heat dissipation performance
Aluminum nitride (AlN) ceramic substrate has a thermal conductivity of 170-230W/(m·K) and a thermal expansion coefficient of 4.5×10-6/℃, which is highly matched with silicon chips (3×10-6/℃, reducing thermal stress stratification and suitable for high-power laser (30W-1000W) packaging.
5. Air tightness and environmental protection
HTCC ceramic shell leakage rate <1×10-8Pa·m³/S, temperature resistance up to 600℃, 1,500 thermal cycles without cracking, ensuring the long-term stability of optoelectronic devices in high temperature and high humidity environments.
Typical application cases:
Optical communication module: HTCC ceramic shell integrates microwave-optical coupling structure and supports 10Gbps optical signal transmission.
High-power laser: AlN substrate provides heat dissipation for fiber lasers and is used in cutting, welding and other scenarios.
Through material innovation (high refractive transparent ceramics) and process optimization (DPC three-dimensional packaging), semiconductor ceramic technology has achieved breakthroughs in high frequency, high reliability and miniaturization in the field of optics.
Chapter 3 Mechanical Strength and Reliability
1. High Mechanical Strength and Impact Resistance
Ceramic materials (alumina, aluminum nitride) have a compressive strength of up to 2,500MPa, a bending strength of 30MPa, and a hardness of 7.5-8.5 on the Mohs scale, which are significantly better than plastic and metal packaging materials. The fracture toughness KIC of zirconia toughened ceramics reaches 12MPa, which can withstand a 20kN cyclic load and effectively resist mechanical damage to optical devices in vibration or impact environments.
2. Thermal stability and low thermal expansion coefficient matching
The thermal expansion coefficient of aluminum nitride (AlN) ceramic substrate is 4.5×10-6/℃, which is highly matched with silicon chip (3×10-6/℃, reducing the risk of thermal stress delamination. The alumina ceramic shell remains stable at 600℃, and there is no cracking after 1,500 thermal cycles (-55℃-150℃), ensuring the long-term reliability of optical communication modules under extreme temperatures.
3. Air tightness and environmental protection
The ceramic shell prepared by HTCC process has a leakage rate of <1×10-8Pa·m³/S and a moisture absorption rate of <0.02%, meeting the IP67 protection level requirements and preventing moisture and pollutants from invading the interior of the optical chip. In an optical communication device under 85℃/85% humidity environment, the ceramic package can maintain a capacitance drift of <0.5%.
4. Corrosion resistance and chemical stability
The corrosion rate of alumina ceramics in strong acid (concentrated sulfuric acid) and strong alkali (NaOH solution) environments is <0.01mg/cm²/year. Aluminum nitride ceramics have no oxidation failure in high-temperature (>600℃) environments containing sulfur gases, and are suitable for chemically corrosive environments of lasers.
5. Anti-electromagnetic interference and structural integration
The shielding effectiveness of the ceramic substrate reaches 60-80dB (@1GHz), and combined with DPC technology to achieve three-dimensional wiring with a line width/line spacing of 30μm, the integration is increased by 3 times, meeting the miniaturization and anti-electromagnetic interference requirements of optical sensors.
Typical applications:
High-power lasers: AlN substrates provide mechanical support and heat dissipation for fiber lasers, and are used in industrial cutting and welding, with a temperature resistance of 1,000℃.
Optical communication modules: CQFN ceramic tube shells integrate microwave-optical coupling structures, support 100Gbps signal transmission, and have vibration resistance that is 3 times better than metal packaging.
Chapter 4 Miniaturization and integration
1. High-density wiring capabilities
The use of DPC (direct electroplating ceramic) technology can achieve line width/line spacing as low as 30μm, through-hole diameter 60-120μm, support three-dimensional cavity structure packaging, and increase integration by more than 3 times. CQFN ceramic shells achieve ultra-thin packaging through surface mounting technology, and the thickness can be compressed to 0.5mm, which is suitable for the miniaturization needs of optical communication modules.
2. Material properties adapt to miniaturization
High refractive transparent ceramics: The transparent ceramics developed by Zhongke Haoye have a refractive index of 1.8-2.2 (adjustable) and a Mohs hardness of 7.5-8.5, which supports the ultra-thin design of AR optical waveguide substrates (thickness <0.2mm).
Aluminum nitride (AlN) substrate: thermal conductivity 170-230W/(m·K), thermal expansion coefficient 4.5×10-6/℃, matching silicon chips, reducing thermal stress stratification in miniaturized packaging.
3. Three-dimensional integration and complex structure
HTCC (high temperature co-fired ceramic) process supports multi-layer ceramic structure, with wiring density of 200 lines/cm², and the diameter of through-hole can be reduced to 50μm, realizing three-dimensional integration of microwave-optical coupling structure. Kyocera’s ceramic shell for LiDAR is 40% smaller than traditional packaging through multi-layer ceramic design.
4. High frequency and low loss performance
The dielectric loss of alumina ceramic is <0.002, and the dielectric constant is 9.8, which supports 40GHz high-frequency signal transmission and meets the miniaturization requirements of optical communication modules (100Gbps optical signal transmission).
Typical application cases:
Optical communication module: HTCC ceramic shell integrates microwave circuit and optical coupler, and the size is reduced to 10mm×10mm, supporting 400Gb/s high-speed transmission.
LiDAR: Aluminum nitride substrate combined with three-dimensional cavity design, packaging volume <5cm³, thermal resistance as low as 0.14K/W.
Through process innovation (DPC fine line processing) and material optimization (high refractive transparent ceramics), ceramic packaging technology is driving optical devices to break through in the direction of miniaturization and high integration.
Chapter 5 Breakthrough Innovation
1. Innovation of high refractive index transparent ceramic materials
The high refractive index transparent ceramics developed by Zhongke Haoye have a refractive index of 1.8-2.2 (adjustable) and a Mohs hardness of 7.5-8.5. They have both high light transmittance (transmittance in a specific band>80%) and scratch resistance, and support AR optical waveguide substrates, laser holographic imaging and other scenarios. Its photochromic function (color change rate ΔR>64%) has potential in the fields of anti-counterfeiting and optical erasure.
2. High frequency and low loss performance
The dielectric loss of alumina ceramics is <0.002, the dielectric constant is 9.8, and it supports 40GHz high-frequency signal transmission, meeting the needs of optical communication modules (100Gbps optical signal transmission). The leakage rate of HTCC process ceramic shell is <1×10-8Pa·m3/S, which ensures the stability of high-frequency signals.
3. High-density wiring and three-dimensional integration
DPC (direct electroplating ceramic) technology achieves line width/line spacing of 30μm and through-hole diameter of 60-120μm. Combined with three-dimensional cavity structure packaging, the integration level is increased by 3 times. The thickness of CQFN ceramic shell can be compressed to 0.5mm, supporting the miniaturization of optical communication modules.
4. Breakthrough in thermal management performance
The thermal conductivity of aluminum nitride (AlN) ceramic substrate reaches 170-230W/(m·K) and the thermal expansion coefficient is 4.5×10-6/℃, which matches the silicon chip and reduces thermal stress stratification. The CPGA shell integrates a heat sink block, which improves the heat dissipation efficiency by 30% and supports high-power laser packaging.
5. Extreme environment adaptability
Zirconia ceramic shell can withstand 600℃ temperature and 1,500 thermal cycles without cracking; AlN substrate has a capacitance drift of <0.5% under 85℃/85% humidity environment, which meets the long-term stability of optoelectronic devices under high temperature and high humidity environment.
Typical application cases:
Optical communication module: HTCC ceramic shell integrates microwave-optical coupling structure, with a size reduced to 10mm×10mm, supporting 400Gb/s high-speed transmission.
AR optical waveguide: Transparent ceramic substrate thickness <0.2mm, adjustable refractive index, used in smart wearable devices.
