To provide an electronic instrument in which a weight load is not applied on a circuit substrate and which is high in reliability under a severe usage in the condition of the vibration or shock of a motorcar or the like, in particular.
The electronic instrument is provided with a structure wherein circuit components provided on the circuit substrate 20 and necessitating heat dissipation are contacted to a heat dissipating plate 23 attached to the circuit substrate 20 with pressure optimum for the heat dissipation. The heat dissipating plate 23 is formed with fixing holes 23a, 23b to fix the circuit components to a case 15 by screwing through the fixing holes 23a, 23b, and the circumference of the circuit substrate 20 is freely maintained in the case 15. The heavy-weight heat dissipating plate 23 is fixed to the case 15 by screwing. By this constitution, the circuit substrate 20 can freely be retained without fixing the same to the case 15 whereby stress is not applied on the soldering part of the circuit components even in a using state that the load of vibration or shock is applied, thereby permitting the improvement of reliability.
INOUE TAKEHIKO
KAWASAKI SHUSAKU
Tomoyasu Sakaguchi
Hiroki Naito