Electronic circuit board

An electronic circuit board comprising:

• a plurality of electronic components to be mounted;
• a plurality of hard rigid board portions each of which has an insulating insulator and a conductive circuit pattern and electrically connects the mounted electronic components to the circuit pattern;
• and
• at least one soft flexible board portion which has an insulating insulator, has a conductive circuit pattern electrically connected to each of the circuit patterns of at least two rigid board portions among the plurality of rigid board portions, and the at least one soft flexible board portion is integrated with the rigid board portions which are electrically connected to the circuit pattern of the flexible board portion,
• wherein when a plurality of contact relays in which occurs resonance therebetween or resonance may occur therebetween as the electronic components is mounted, the plurality of the contact relays is dispersedly arranged on the respective rigid board portions, and
• wherein when a number of the contact relays to be mounted is larger than a number of the rigid board portions, the contact relays are mounted, one by one, on the respective rigid board portions, and at least one of the contact relays is mounted on each of the rigid board portions as many as a number of the remaining contact relays selected from among the respective rigid board portions.