Method for manufacturing oscillator

A method for manufacturing oscillators of a plurality of types including a first oscillator and a second oscillator, the method comprising:

• preparing a first container having a first outer base and a first lid, the first outer base having a first monolithic structure, the first outer base having a first surface and a second surface outwardly opposite to each other along a first direction;
• forming a first recess and a second recess in the first and second surfaces, respectively;
• manufacturing the first oscillator, the manufacturing the first oscillator including:
• a first-oscillator first step of mounting a first resonator element and a first circuit element in the first recess of the first outer base, the first circuit element being configured to oscillate the first resonator element to generate a first oscillation signal;
• and
• a first-oscillator second step of mounting a second resonator element in the second recess of the first outer base, an oscillation frequency of the second resonator element being controlled based on the first oscillation signal;
• preparing a second container having a second outer base and a second lid, the second outer base having a second monolithic structure, the second outer base having a third surface and a fourth surface outwardly opposite to each other along the first direction, wherein the second container has a same size and a same outer shape as the first container such that the first outer base has a same size and a same outer shape as the second outer base;
• forming a third recess and a fourth recess in the third and fourth surfaces, respectively;
• and
• manufacturing the second oscillator, the manufacturing the second oscillator including:
• a second-oscillator first step of mounting a third resonator element and a second circuit element in the third recess of the second outer base, the third resonator element having a same size as the first resonator element, the second circuit element having a same size as the first circuit element, the second circuit element being configured to oscillate the third resonator element to generate a second oscillation signal;
• and
• a second-oscillator second step of mounting a fourth resonator element in the fourth recess of the second outer base, an oscillation frequency of the fourth resonator element being controlled based on the second oscillation signal, the oscillation frequency of the fourth resonator element being different from the oscillation frequency of the second resonator element.