| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a lightweight/thin type key board which has a large heat radiating effect by closely sticking flexible graphite sheet to almost all over a shield plate bottom surface. SOLUTION: This device is equipped with a key top 1, a key board frame 2, circuit patterns 3a and 3b, a shield plate 4, a elasticity body 5a consisting of a rubber material having a projection 5b, a flexible graphite sheet 6, a CPU 7 which is heat radiating parts, and a wiring substrate 8. An aluminum alloy plate is used as this shield plate 4, and one flexible graphite sheet 6 is stuck to the bottom surface for improving a heat radiating effect. A heat radiating surface of a heat radiating body 7 provided on the wiring substrate 8 and the graphite sheet 6 are in direct contact with each other. Heat of the heat radiating body 7 is directly transmitted to the graphite sheet 6 in a horizontal direction, and is transmitted to the shield plate 4. The heat of the shield plate 4 is transmitted vertically and horizontally inside itself.</p> |
