In my thesis I designed a four-layer LTCC resistor circuit which contains 72 embedded resistors with different l/d ratio. I went through the technology of the LTCC and I made the designed circuit successfully. After the firing, the carrier was unhurt and there wasn’t short or break in the circuit.
After firing the carrier, every value of the resistors was the half as the planned values. The reason can be that the printing height of the resistor layer was too thick. To demonstrate that problem I made some checking process. Finally the cross polish process made the result that I waiting for. These results show well that the height of the resistor and conductor layer were thicker that I planned. The reason of the thicker layers can be the wrong viscosity of the composition, the too high emulsion on the screen or the bigger diameter of the screen’s wire.
As I got to know and went through every step of the technology of LTCC, I determine that we are able to make LTCC circuits with buried resistors in the laboratories of the Department of Electronics Technology. If we can check perfectly the printing thickness than we can make buried resistors between the tolerances of the LTCC technology for buried resistors.