In recent years, attention has focused on methods for manufacturing electronic devices by ink-jet technology.
According to a piezoelectric element in Patent Literature 1, electrodes provided on two ends along a short side of the piezoelectric element can be removed from one side of the piezoelectric element. The structure will be discussed below.
FIG. 7(a) is a plan view of a first ceramic green sheet 30. FIG. 7(b) is a plan view of a second ceramic green sheet 40. Hereinafter, the first ceramic green sheet 30 will be called a first sheet and the second ceramic green sheet 40 will be called a second sheet.
In the conventional piezoelectric element, as shown in FIG. 8, the first sheets 30 and the second sheets 40 are stacked on a lower part 90, and then are pressed and burned thereon.
A first electrode 50 of conductive paste is formed on the first sheet 30. A second electrode 60 is formed on the second sheet 40. The first electrode 50 has a first non-electrode region 51 and the second electrode 60 has a second non-electrode region 61.
The first and second sheets 30 and 40 are stacked, pressed, and burned so as to obtain a block 20 as an intermediate product shown in FIG. 8(a). FIG. 8(a) is a perspective view of the block 20. The front surface will be called a front surface 20a, the rear surface will be called a rear surface 20c, the right lateral surface will be called a right lateral surface 20b, and the left lateral surface will be called a left lateral surface 20d. 
The first electrodes 50 are exposed only on the front surface 20a of the piezoelectric element 20 but are not exposed on the right lateral surface 20b, the left lateral surface 20d, and the rear surface 20c of the piezoelectric element 20.
The second electrodes 60 are exposed on the rear surface 20c but are not exposed on the front surface 20a, the right lateral surface 20b, and the left lateral surface 20d. Connection electrodes 70 are exposed on the front surface 20a, the right lateral surface 20b, and the rear surface 20c of the piezoelectric element. In other words, the connection electrodes 70 are formed up to the front surface 20a and the rear surface 20c of the piezoelectric element 20 that are opposed to each other.
FIG. 8(b) shows the rear surface 20c of the piezoelectric element 20. The connection electrodes 70, the second electrodes 60, and the second non-electrode region 61 are shown on the front surface.
As shown in FIG. 8(c), a conductive layer 100 is formed over the rear surface 20c and requires more piezoelectric elements. As shown in FIG. 9, a plurality of slits 91 are formed so as to constitute the piezoelectric element 20.
The piezoelectric element 20 includes the connection electrodes 70 and the second electrodes 60 that are electrically connected to each other on the rear surface 20c via the conductive layer 100. Thus, the first electrodes 50 and the connection electrodes 70 are connected to external electrodes on the front surface 20a, activating a piezoelectric substance. Hence, external connection can be made only on one of the surfaces of the piezoelectric element 20. The surface is connected to a substrate having a number of external connection electrodes, thereby driving the piezoelectric elements. The piezoelectric element 20 used for an inkjet requires quite a number of piezoelectric substances, and a plurality of external electrodes need to be removed from one of the surfaces (front surface 20a) of the piezoelectric element 20.
FIGS. 10(a) to 10(c) show displacements when a voltage is applied to the piezoelectric element 20. Specifically, an upper view shows a cross section of the piezoelectric element 20 while a lower view shows a displacement in this state. In this case, the cross section is perpendicular to the front surface 20a and the rear surface 20c of the piezoelectric element 20 in FIG. 8.
In FIG. 10(a), symmetric displacements appear when d1=d2 is satisfied where d2 and d1 are the widths of the second non-electrode region 61 and the first non-electrode region 51 on the two ends of the piezoelectric element 20.
As shown in FIG. 10(b), when “d1>d2” is satisfied, the displacement of the smaller d2 is larger than that of the larger d1. As shown in FIG. 10(c), when “d1<d2” is satisfied, the displacement of the smaller d1 is larger than that of the larger d2.
As described earlier, the locations of the maximum displacement of the piezoelectric element 20 vary depending upon the widths d1 and d2 of the non-electrode regions 51 and 61. In other words, the maximum displacement position and the maximum displacement of the piezoelectric element 20 vary depending upon the values of the widths of the non-electrode regions.
The values of the widths of the non-electrode regions vary because of the forming accuracy of the formed electrodes, a displacement when the ceramic green sheet is stacked, the degree of shrinkage during burning, and so on.