| 摘要 |
PURPOSE:To improve the response at low frequencies, by forming folds at a part of diaphragm plate of a small-sized sound production body through an etching processing. CONSTITUTION:A photoresist 2 is coated on upper and lower surfaces of a diaphragm plate 1 to form the pattern 2b with folds. Next, grooves 4 for folds are formed with etching, the photoresist is removed and the diaphragm plate 5 having the grooves 4 with folds is formed. Thus, by forming folds at the outer circumference of the diaphragm plate, since the thickness of grooves with folds can extremely be made thin in comparison with the thickness of the diaphragm plate, the frequency characteristics of the sound body is extended to low band. |
