| 摘要 |
PURPOSE:To improve the cooling efficiency by a method wherein the circuit board surface on which circuit elements are mounted is provided with a plurality of recess grooves narrower than the element in a fixed direction, and the projected region of the board is provided with electrodes which connect the elements to the board. CONSTITUTION:Semiconductor elements 6' are mounted across the recess grooves 11 of the circuit board 10. For this purpose, the semiconductor element 6' is formed in a pattern provided with electrode pads 6p connecting the element to the board only on both sides. Besides, a recess groove 11 narrower than the element is provided in a fixed direction of the board. This construction allows air-bubbles of 0.5-1mm.phi to rise out of the surface of the element 6' opposed to the board 10 and then to come up by separation off from the element surface, resulting in the cooling of the board by stirring and circulating the coolant with the air bubbles. Therefore, the elements 6' are cooled by boil-stirring from both of the back and opposed surfaces, and the cooling efficiency increases about double. Semiconductor elements can be mounted on a circuit board with much higher density, and the element itself can be further increased in integration. |
