The Study Of Multi-layer Ceramic Transformer

As a new type of transformer, the Multi-layer LTCC transformer has developed quite rapidly in recent years. It challenged traditional designing and processing technology with a brand-new processing technique of applying LTCC technology, which was short for Low Temperature Co-fired Ceramic. Compared with transformers made with traditional techniques, this new LTCC transformer boasts of many good virtues, such as small in size, high in reliability, easy in storage and convenient in delivery, etc. With the fast-growing Ferrite material technology and the gradual perfection of LTCC technology, the foundry cost of LTCC transformer will be further lowered down, and its usage and application would thus be greatly promoted. That was one of the critical reasons why this type of transformer getting so much attention.This paper starts with an introduction of the common structure of mini-type transformers, together with an analysis of inductor loop structure and transformer equivalent circuits. Based on the general knowledge of mini-type transformer structure, the LTCC multi-layer technology has been thoroughly studied, and achieved with the exploration of designing technique of multi-layer sheet LTCC transformers, the complanation of transformer layout setting layer by layer, the completion of layout and processing flowchart designing through analysis&research of layout structure and processing procedures. During production of the LTCC transformers, the ferrite green-tape and the common LTCC processing procedure compatibility has been carefully studied, with achievement in eliminating processing problems like via-fill paste gibbosity, delamination, surface cracks of fired LTCC substrates, etc. The transformer sample was built up successfully with the processing conditions being optimized by way of crossover experiments.