JPS60152114A - Surface acoustic wave element - Google Patents

Abstract

PURPOSE:To prevent the electric performance from being changed even if conductive foreign materials are adhered by coating a resin only on an electrode pattern. CONSTITUTION:The application of a resin 5 to a comb line electrode 4 on a piezoelectric substrate 3 prevents the electric performance from being changed even if conductive foreign materials 6 are adhered. In this case, it is constituted that the resin is removed on the propagation path of the surface acoustic wave and the wire bonding pad. In order to realize it, a resist pattern for electrode forming is formed and after etching, the photoresist is not removed but left as it is.

Description

[Detailed description of the invention] [Field of application of the invention] The invention relates to surface acoustic wave elements.

[Background of the invention]

In conventional surface acoustic wave elements, the electrode patterns are not coated in any way. The reason for this is that the surface acoustic wave element itself is a device that uses surface acoustic waves that propagate on a substrate, and if something is coated on the polar pattern or the substrate, the electrical characteristics will change. It depends. If conductive foreign matter adheres to the electrode pattern,
There was a drawback that the electrode pattern was short-circuited and desired electrical characteristics could not be obtained.

[Purpose of the invention]

An object of the present invention is to provide a 1M resistor with an elastic surface that does not cause any change in electrical performance even if conductive foreign matter adheres to the single-pole pattern.

[Summary of the invention]

There are two countermeasures C for dealing with conductive foreign matter that is generated from the manufacturing process and materials and adheres to the pattern.

One is to eliminate the generation of these foreign substances, but this is almost impossible. One remaining method is to coat the surface of the pattern so that there is no problem with the adhesion of foreign matter. However, as mentioned above, this method is not possible because the electrical characteristics change if (iI) is applied on the substrate.For this reason, the present invention (5) is to apply resin only on the pattern. This is what I did.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

A cross section of the comb-shaped electrode pattern 1 of the surface acoustic wave device as shown in FIG. 1 is shown in FIGS. 2 and 3. In the case of FIG. 2 where no coating is applied, the comb-shaped electrodes 4 on the piezoelectric substrate are exposed, and if conductive foreign matter 6 adheres, the electrical characteristics of the surface acoustic wave element as shown in FIG. The value becomes like a broken line, which is normal (significantly lower than the actual value).

Therefore, if the resin 5 is made to exist on 1!44 as shown in Figure 3, there will be no problem even if the 4# tortoise proboscis is attacked.

In this example, the photosensitive resin (photoresist) used for forming the comb-shaped electrodes was used. In other words, electrodes are formed by etching after forming a resist pattern.

However, after etching, we decided to leave the photoresist as is without peeling it off. In the figure, 2 is a pad pattern and 6 is a substrate.

As a result, no problem occurred in reliability even if any conductive foreign matter adhered thereto.

【Effect of the invention〕

In conventional devices, stray conductive foreign substances during the manufacturing process and welding chips during can sealing (adhering to the rectangular electrodes) result in short-circuiting of adjacent electrodes, resulting in the failure of desired electrical characteristics. There are a few to 10% of defects that cannot be corrected.

Was.

However, according to the present invention, even if the above-mentioned phenomenon occurs, conduction does not occur between the electrodes, so that no defects occur.In other words, the yield of the manufacturing process and the reliability of the device as a product are significantly improved.

[Brief explanation of the drawing]

Fig. 1 shows the pattern of the surface acoustic wave device. Fig. 1 is a plan view, Fig. 2 and Fig. 3 are cross-sectional views of the electrode pattern, and Fig. 4 is a characteristic diagram showing the electrical characteristics of the surface acoustic wave device. It is. 1...Electric pattern 2...Pad pattern 3rd 1st circle 3rd ring 40th □Q&A

Claims (1)

[Claims] In a surface acoustic wave device consisting of a chip in which comb-shaped electrodes are formed on a piezoelectric substrate and a package in which the chip is inserted, an insulating resin is provided on the top of the comb formation, and an insulating resin is provided on the surface acoustic wave propagation path and in the wire bonding pad portion. A surface acoustic wave element characterized in that the above-mentioned insulating resin is removed.