变频组件LTCC基板内埋宽带滤波器的性能优化

Property Optimization of Broadband Filter Buried in LTCC Substrate for Frequency-conversion Module

LTCC基板内埋滤波器是实现变频组件小型化的有效手段之一。重点研究了LTCC基板内埋宽带滤波器15~16 GHz频带内掉坑问题。运用因果图定位到了8条末端因素,结合HFSS仿真结果,确认了主要原因为印刷图形间距超差和撕膜后生瓷片收缩量大。通过调整网版印刷方向和监控刮刀刀口磨损程度,优化印刷图形质量。从撕膜参数、生瓷预处理和浆料干燥方式共3个方面,对撕膜后生瓷片形变量进行有效控制。滤波器测试结果表明,15~16 GHz频带内掉坑问题得到了有效解决。

The process of filter buried in LTCC substrate is one of the effective methods to achieve miniaturization of frequency-conversion module.The problem of pit between 15~16 GHz of broadband fi lter buried in LTCC substrate is mainly studied.Eight end factors are identified by cause-and-effect diagram.Combined with HFSS simulation results,it is confi rmed that the main reasons are out of tolerance of printing pitch and the large shrinkage of green tape after film uncovering.By adjusting the printing direction and monitoring the wear of the blade edge of the scraper,the quality of printing graphics is optimized.The shape variation of green tape is effectively controlled by means of optimizing film uncovering parameters,the pretreatment of green tape and the paste drying mode.The fi lter test results showed that the problem of pit in the 15~16 GHz frequency band is effectively solved.