The Research Of Measuring Methods For Forming Defects Of RF Module And The Development Of Measurement System

The RF module uses the LTCC as the material by lamination, co-firing, chip-interconnection, hybrid lamination and other key technology to achieve the prototyping and manufacturing of multi-layer ceramic circuit or multi-layer micro-strip circuit.The RF module will be subjected to heat energy, mechanical energy, chemical energy and other energy during the molding process. These energies will generate stress and strain in the inner-layer, interlamination and the RF module system, resulting in the deformation of micro-channel, the warping of the substrate and the displacement-error of the vertical interconnection at last. Also, the unsuitable process parameters will result in voids issue during eutectic bonding between the chip and the RF module. These series of defects will affect the forming quality and functional characteristics of the antenna-feeder system.Researching the measuring methods of the deformation of micro-channel, the warping of the substrate, the displacement-error of the vertical interconnection and the voids issue is the main content of this paper. Finding the suitable and accurate measurement methods for these defects will provide reference date for the molding process of the RF module. The main contents are as follows:1. The study of the measuring methods for the warping of RF module. This paper introduces the definition of warping and makes a detailed analysis for the measuring object. According to the characteristics of RF module and requirements for measurement, this thesis presents two optical measurement methods and obtains the warping of specific sample by using the two optical methods.2. The study of the measuring methods for voids ratio of soldering. This paper introduces the background of chip welding, X-ray imaging theory, ultrasound microscopy imaging theory and achieves nondestructive measurement by using X-ray imaging, ultrasound imaging and image processing technology at last.3. The study of the measuring methods for the size of micro-channel which inside RF module and the displacement-error of vertical interconnection. According to the requirements of nondestructive measurement, this thesis presents the industrial CT imaging technology and the image processing technology which are used to measure the two defects.4. The study of image processing technology. This paper researches a variety of image pre-processing algorithms and verifies the effect of different algorithms by the experiments of image processing.5. The development of the measuring system. The thesis develops a measurement system that can be used for measuring the void ratio, the size of micro-channel inside RF module and the displacement-error of vertical interconnection based on the Matlab software platform by using image processing technology.