JPS61128618A - Manufacture of surface acoustic wave device - Google Patents

Abstract

PURPOSE:To improve the good product rate by irradiating a laser through a metallic film provided on a glass plate forming a surface acoustic wave device to suppress the generation of cracks of the glass plate. CONSTITUTION:Plural pairs of input interdigital electrodes 12, output interdigital electrodes 13 and a piezoelectric film 14 are formed on one major surface 11a of the glass plate 11. On the other hand, a metallic film 15 is formed on the other major surface of the glass plate 11. Then a laser is irradiated from the metallic film 15 to form a cut slot 16, at which the glass plate 11 is split to separate surface acoustic wave devices. In irradiating the laser on the glass plate 11, a thermal shock applied to the glass plate is diffused by the metallic film 15 to reduce cracks on the glass plate. Thus, the good product rate is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a surface acoustic wave device using glass as a substrate.

(Prior Art) In general, a surface acoustic wave device using glass as a substrate has comb teeth on the main surface of a glass substrate 1 made of alkali-free glass, etc., as shown in FIGS. 3(a) and 3(b). An input-side interdigital electrode 2 and an output-side interdigital electrode 3 are formed with a distance between their centers, and a piezoelectric film 4 of ZnO is formed thereon, so that the electricity applied to the input-side interdigital electrode 2 is A surface wave VO is generated in the piezoelectric HtA4 on the input side interdigital electrode 2 by the signal and propagates through the piezoelectric film 4 and the glass substrate 1 as a medium.
It has a configuration in which the output-side interdigital electrode 3 converts the signal into an electric signal again and extracts it.

Conventionally, in order to manufacture a surface acoustic wave device having the above-mentioned configuration, as shown in FIG. The input side interdigital electrode 2 and the output side interdigital electrode 3 shown in FIG. 3(a) are formed in the section 6 shown.

Thereafter, the entire or partial main surface of the glass plate 5 on which the input-side interdigital electrodes 2 and the output-side interdigital electrodes 3 are formed is coated with a piezoelectric material film (not shown) made of ZnO by a sputtering method. ) to form. The two-dot chain line in FIG. 4 shows this glass plate 5 from its other main surface side! As shown in FIG. 3(a), it is cut using a diamond blade or a carbide roll blade (none of which is shown), and separated into the surface acoustic wave device shown in FIG. 3(a).

By the way, in the above-mentioned conventional method for manufacturing a surface acoustic wave device, when forming a piezoelectric material film by sputtering, thermal strain is applied to the glass plate 5 during this sputtering. Due to this thermal strain, cranks, etc. occur in the glass plate 5 when the glass plate 5 is cut (scribed) with a diamond blade, a carbide roll blade, etc., resulting in a problem that the yield rate during the manufacture of surface acoustic wave devices is low. Ta.

(Purpose of the Invention) The present invention has been made in view of the above-mentioned problems in the manufacturing method of a surface acoustic wave device using a plastic plate. The present invention aims to provide a method for manufacturing a surface wave device.

(Structure of the Invention) For this reason, the present invention forms a metal film on another main surface side opposite to the main surface of the glass plate on which the piezoelectric material film is formed, and irradiates laser from above this metal film. This method is characterized in that a cutting groove is formed in the substrate, and the surface acoustic wave device formed on the glass plate is separated using the cutting groove. That is, in the present invention, a metal film is formed on a positive plate on which a surface wave device is formed, and the glass plate is cut by irradiating the positive plate with a laser through the metal film. When the plastic plate is irradiated with a laser, the thermal shock applied to the glass plate is diffused by the metal film, reducing the occurrence of cracks on the plastic plate.

(Effects of the Invention) According to the present invention, since the laser is irradiated through the metal film formed on the glass plate forming the surface wave device, the thermal shock caused by the laser irradiated on the glass plate is diffused by the metal film. When cutting the glass substrate and separating the surface acoustic wave devices formed on it, cracks are less likely to occur on the glass substrate, and the yield rate during the manufacturing of surface acoustic wave devices can be greatly improved. .

(Example) Hereinafter, a method for manufacturing a surface acoustic wave device according to the present invention will be described with reference to the accompanying drawings.

First, as shown in Fig. 1(a), the − side is, for example, 50 m.
A plastic plate 11 made of borosilicate glass or the like with a thickness of 0.7 am and a thickness of 0.7 am is prepared.

As shown in FIG. 1(b), this glass plate 11 has a plurality of pairs of input-side interdigital electrodes 12 and output-side interdigital rings Fii 13 on one main surface 11a, just as shown in FIG. form. These input-side interdigital ring w1.12 and output-side interdigital electrode 13 can be formed, for example, by vapor deposition of aluminum (Af) and etching.

Thereafter, as shown in FIG. 1(c), Zn is deposited on the main surface 11a of the glass plate 11 by sputtering.
A piezoelectric material film 14 made of O or the like is formed.

On the other hand, on the other main surface 11b of the glass plate 11, a metal film 15 of nickel (Ni) is formed as shown in FIG. 1(d). This metal film 15 can be formed by a method such as printing or vapor deposition. Its thickness is about 3 μm when it is formed by printing, and about 0.6 μm when it is formed by vapor deposition. Note that this metal film 15 is connected to the input side interdigital electrodes 12. It may be formed before forming the output side interdigital electrodes 13, and these input side interdigital electrodes 12. It may be formed between the step of forming the output side interdigital electrode 13 and the step of forming the piezoelectric material film 14.

In this way, the glass substrate 11 with the metal film 15 formed on the main surface 11b is coated from above the metal film 15 as shown in FIG.
As shown by arrow A in d), for example, a Co2 laser is irradiated to form a cutting groove 16 having a depth d of, for example, 0.18 mm.

The glass substrate 11 is broken at the cutting groove 16 to separate the surface acoustic wave device.

The surface wave device separated in this way is shown in Figure 2(a).
As shown in FIG. 2(b), the lead-out electrodes 12a and 12b of the input side interdigital electrode 12 have a lead-out type 1M.
Terminal electrodes 22a and 22b are soldered to the extraction electrodes 13a and 13b of the output side interdigital electrode 13, and a ground terminal 23 is soldered to the metal film 15, respectively, and then the terminal electrodes 21a and 21b are covered with an exterior resin 24. Ru.

If the CO2 laser is irradiated onto the lath plate 11 through the metal film 15 formed in advance as described above, as described above,
Thermal shock generated when the lath plate 11 is irradiated with the CO2 laser is diffused by the metal film 15, and even if thermal strain is applied to the glass plate 11 during the formation of the piezoelectric film 14 by sputtering, the glass plate 11 will not be damaged during scribing. 11 is less likely to develop cracks.

Further, as described above, the metal film 15 can be attached with the earth terminal 23 and used as a shielding electrode. This metal film 15 can also be made of metal materials other than nickel.

According to the embodiment of the present invention described above, the substrate 11
By reducing the occurrence of cracks, the cut yield rate of the surface acoustic wave device was improved from 96% to 99%.

[Brief explanation of drawings]

Figure 1(a), Figure 1(b), Figure 1(c) and Figure 1
Figure (d) is an explanatory diagram of the method for manufacturing a surface acoustic wave device according to the present invention, respectively. ) is shown in Figure 2(a)
A cross-sectional view along the line II-II of the surface acoustic wave device shown in FIG.
) is a plan view of a surface wave device manufactured by a conventional manufacturing method, and FIG. 3(b) is a plan view of the surface wave device of FIG. 3(a).
FIG. 4, a cross-sectional view taken along line IV, is an explanatory diagram of a conventional method of manufacturing a surface acoustic wave device. 11... substrate (lla, 1111... main surface)
, 12... Input side interdigital electrode, 13...
Output side interdyntal electrode, 14... piezoelectric material film,
25... Metal film, 16... Cutting groove. 1st cause 11o 23 15 11bt゛Figure 3 4th cause

Claims (1)

[Claims] (1) A single glass plate with multiple pairs of input-side interdigital electrodes and output-side interdigital electrodes and a piezoelectric material film formed on one main surface is connected to a pair of input-side interdigital electrodes and output-side interdigital electrodes. A method for manufacturing a surface wave device, the method comprising: forming a metal film on the other main surface of the glass plate, and irradiating the metal film with a laser to cut the surface wave device. A method of manufacturing a surface acoustic wave device, comprising forming grooves and cutting the glass plate.