A piezoelectric resonance device wherein both ends of a piezo-resonator which has oscillation electrodes on both sides of a piezoelectric substrate are soldered to the inside of cup portions of input and output terminals respectively, and a pair of opposed capacity electrodes of a capacitor is soldered to the outside of the cup portions. The capacitor has a width larger than that of the cup portions.

An electronic component involving a 3-terminal type piezo-electric device is disclosed. The piezo-electric device connected to a first terminal, and a capacitor connected to both a second terminal and the outside of the first terminal are firmly supported by first and second supporting means, so that the connecting work can be easily carried out, and that the connection state can be firmly maintained, thereby upgrading the reliability of the electronic component involving the 3-terminal type piezo-electric device. The electronic component involving a 3-terminal type piezo-electric device includes a device part 110 having a piezo-electric device 111 and a capacitor 115. A terminal part 120 has a first terminal 123 with bent portions to surround both ends of the piezo-electric device 111 and to be connected to the capacitor 115, and a second terminal 124 for being connected to the outer face of the capacitor 115. A lead part 130 has first and second leads 132 and 136 and a frame 133 for integrally connecting the lower ends of the first and second leads 132 and 136. A supporting part 140 has first and second supporting means 141 and 142 extending downward integrally from the connecting portion between the first terminal 123 and the first lead 132.

Aspects of the invention provide piezoelectric resonator element having a plurality of grooves for suppressing propagation of the thickness shear vibration from the center portion to the outer peripheral portion of the main surface being placed in enclosure-like shapes surrounding the center portion of at least one of the main surfaces.

A composite electronic component provided is one with sufficient impact resistance. In this resonator 1, a capacitive element 3 has a projection 37 projecting outside a piezoelectric element 2, from a portion of the capacitive element 3 coinciding with a vibration region 2a. The projection 37 is provided on each of two sides of the capacitive element 3 in a direction substantially perpendicular to a longitudinal direction of the capacitive element 3. This causes the projections 37 of the capacitive element 3 to be buried in a mold resin 5, whereby the capacitive element 3 is sufficiently fixed to the mold resin 5 even if the mold resin 5 is provided with a vibration space 5a containing the vibration region 2a of the piezoelectric element 2. Therefore, an improvement is made in impact resistance of the resonator 1.

First and second grooves (15, 16) are formed in upper and lower surfaces of a piezoelectric ceramic plate (12), which is polarized in a direction P parallel to its major surfaces, respectively. A resonance part is formed between the first and second grooves (15, 16), so that first and second resonance electrodes (13, 14) which are provided on the upper and lower surfaces of the piezoelectric ceramic plate (12) respectively are opposed to each other through the piezoelectric ceramic plate (12). In this energy trap type piezo-resonator utilizing a thickness shear mode, the resonance part has a pair of rectangular side surfaces, and the first and second grooves (15, 16) are so formed that a ratio b/a is in a range of .+-.10% from the following value: assuming that b and a represent lengths of longer and shorter sides of the rectangular side surfaces of the piezoelectric body respectively, .sigma. represents the Poisson's ratio of the material forming the resonance part, and n represents an integer.