Inside is composed of electronic components and circuits, now the IC is generally specialized in dealing with a certain function, easy to use, but also save the board area.
Instead of diode and transistor, reduce the volume and cost, two transistor IC patch code refers to the abbreviation code on the surface of the component body, English is markingcode,top mark,marking, the process has two kinds of screen printing and laser.
Because the size of the patch components is relatively small, it can not accommodate the complete model, so each manufacturer has established its own abbreviation code rules, and a very brief combination of several letters and numbers + symbols is laser or screen printed on the surface of the tube body as the model mark to distinguish the model.