Modified NiO-Ta2O5 Microwave Ceramic for Low-Temperature LTCC Sintering
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Solution Overview
Problem
Traditional NiO—Ta2O5 ceramics cannot be co-fired with Ag or Cu electrodes in low-temperature co-fired ceramic (LTCC) technology due to high sintering temperatures, and they lack low-temperature sintering capabilities while maintaining excellent microwave dielectric properties.
Innovation Solution
A modified NiO—Ta2O5-based microwave dielectric ceramic material with a general chemical formula of (1.587y-0.198xy)ZnO-(2.597y-0.324xy)CuO-(1-x)NiO-(1.855y-0.231xy)B2O3-3xSnO2-(1-x)Ta2O5-(0.284y-0.035xy)V2O5 is developed, allowing for low-temperature sintering between 875-950°C, achieved through the addition of sintering aids like CuO, V2O5, and B2O3, and ion doping, which stabilizes the NiTa2O6 structure and maintains excellent microwave dielectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional NiO-Ta2O5 ceramics are sintered at high temperature (1400°C) to maintain microwave dielectric properties, then the dielectric constant and quality factor are improved, but the sintering temperature becomes too high for LTCC co-firing with Ag or Cu electrodes
Solution Approach 1:
The patent changes the chemical composition parameters by introducing ZnO, CuO, B2O3, SnO2, and V2O5 modifiers to the NiO-Ta2O5 system. This compositional parameter change enables the ceramic to be sintered at lower temperatures (900-950°C) while maintaining stable microwave dielectric properties, making it compatible with LTCC co-firing processes for Ag or Cu electrodes
Solution Approach 2:
The patent creates a composite ceramic material by combining NiO-Ta2O5 base ceramic with multiple oxide modifiers (ZnO, CuO, B2O3, SnO2, V2O5). This composite structure achieves synergistic effects where the modifiers lower the sintering temperature and improve microwave dielectric properties simultaneously, enabling both low-temperature processing and high performance
2Temperature
If the sintering temperature is reduced for LTCC compatibility, then co-firing with Ag or Cu electrodes becomes possible, but the microwave dielectric properties may deteriorate
Solution Approach 1:
The patent optimizes the composition parameters of the ceramic system by precisely controlling the ratios of NiO, Ta2O5, and modifier oxides. This parameter optimization ensures that even at reduced sintering temperatures (900-950°C), the ceramic maintains excellent microwave dielectric properties with dielectric constant εr=25 and quality factor Q×f=31200 GHz
Solution Approach 2:
The patent introduces oxide modifiers (ZnO, CuO, B2O3, SnO2, V2O5) as intermediaries that facilitate low-temperature sintering. These modifiers act as sintering aids that promote grain growth and densification at lower temperatures, thereby maintaining microwave dielectric properties despite the reduced sintering temperature
3Stability of the object's composition
If traditional NiO-Ta2O5 ceramics are used, then the crystal structure is stable, but the temperature coefficient of resonance frequency Tf is too large for excellent temperature stability
Solution Approach 1:
The patent modifies the compositional parameters by introducing ZnO, CuO, and other modifiers that substitute into the NiTa2O6 crystal structure. This compositional modification adjusts the temperature coefficient of resonance frequency Tf to a smaller value, achieving excellent temperature stability while maintaining crystal structure stability through the robust NiTa2O6 framework
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The modified ceramic material achieves reduced sintering temperatures while maintaining dielectric constants of 17-21, quality factors of 14,000-23,000 GHz, and temperature coefficients of resonance frequency between 5-10 ppm/°C, making it suitable for LTCC technology with improved temperature stability and microwave performance.
Implementation Method 1
the sintering temperature of the microwave dielectric ceramic material is 875-950° C., and the microwave dielectric ceramic material is pre-sintered in the atmosphere environment of 850-900° C.
Implementation Method 2
microwave dielectric ceramics can play a functional role in the range of 300 MHz-300 GHz
Data Source
AI summary
The invention belongs to the field of electronic ceramics and its manufacturing, in particular to the modified NiO—Ta2O5-based microwave dielectric ceramic material sintered at low temperature and its preparation method. It is guided by ion doping modification, not only considering the substitution of ions with similar radius, such as Zn2+ replacing Ni2+ ions, V5+ replacing Ta5+ ions; Meanwhile, the selected doped oxide still has the property of low melting point. Therefore, the microwave dielectric properties of NiO—Ta2O5-based ceramic material can be improved and the appropriate sintering temperature can be reduced. In the invention, by adjusting the molar content of each raw material, the NiO—Ta2O5-based ceramic material with low-temperature sintering, stable temperature and excellent microwave dielectric property is directly synthesized at one time, which can be widely applied to the technical field of LTCC.