An improved cooling system provides cooling away from the surface of electrical and electronic components with very low parasitic power consumption and very high heat transfer rates. The sub-line is set, in the width, narrower than the main line and both side edges of the sub-line are allocated at the internal side of both side edges of the main line. The physical microphones make use of a common rear vent that samples a common pressure source. Thus, the undesired oxide at the bottom of the contact hole is removed while the enlargement of the contact hole is minimized. Next, the supporting substrate is separated into each chip.