JPH09167932A - Manufacture of surface acoustic wave filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electrodes from being destroyed by preventing the adjacent electrodes with each other from discharging even if static electricity is generated due to mechanical friction and a temperature change when the patterns of the electrodes, etc., to be components of a surface acoustic wave filter are formed on a wafer. SOLUTION: On the outer peripheral sides of the components (electrodes 3, 4 and 5) of a surface acoustic wave filter, the pattern of the connection path 10 connecting the components is formed. A wafer 1 is cut along a scribe line to form a chip single substance. At this time, the outer peripheral path 12 part connecting between at least the components 3, 4 and 5 of the connection path 10 is cut by the cut path 20 and the components 3, 4 and 5 are electrically separated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a surface acoustic wave filter, and more particularly, when forming a pattern of a plurality of electrodes or the like which are constituent elements of the surface acoustic wave filter on a wafer which is a piezoelectric substrate. , Those that can effectively eliminate the adverse effects of static electricity and the like.

[0002]

2. Description of the Related Art A surface acoustic wave filter usually has a pattern of a plurality of comb-teeth electrodes (IDT electrodes) serving as input / output transducers and reflective electrodes (REF electrodes) serving as grating reflectors formed on a piezoelectric substrate. In manufacturing the surface acoustic wave filter, as shown in FIG. 2, the surface acoustic wave filter is mounted on a piezoelectric substrate (wafer) 1 which can be divided into a large number of chips to be the surface acoustic wave filter. The IDT electrodes 3, 4 and REF which are constituent elements
The electrode 5 and the scribe patterns 6, 6, 6, 6 are formed by patterning with a mask and vapor-depositing aluminum, and then the wafer 1 is scribed to connect the scribe patterns 6, 6, 6, 6. A single chip that becomes the surface acoustic wave filter is obtained by cutting along the line.

[0003]

As described above, the IDT which is a constituent element of the surface acoustic wave filter on the wafer 1 is formed.
In the process of forming the pattern of the electrodes 3, 4 and the REF electrode 5, static electricity may be generated due to mechanical friction or temperature change. At this time, the adjacent electrodes 3, 4, 5 are discharged to each other, and the electrode 3, 4, 5 may be destroyed.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a component of a surface acoustic wave filter on a piezoelectric substrate (wafer).
In the process of forming a pattern such as a DT electrode or a REF electrode, even if static electricity is generated due to mechanical friction or temperature change, it is prevented that adjacent electrodes are discharged, and the electrodes are destroyed. It is an object of the present invention to provide a method of manufacturing a surface acoustic wave filter which is capable of improving the yield and quality by preventing the above.

[0005]

In order to achieve the above-mentioned object, a method of manufacturing a surface acoustic wave filter according to the present invention is a method of manufacturing a surface acoustic wave filter on a wafer which can be divided into a large number of chips to be surface acoustic wave filters. When forming a pattern of a plurality of electrodes or the like which are constituent elements of a wave filter, a pattern of a connecting path connecting them is formed on the outer peripheral side of the constituent elements so as to connect all of the constituent elements, and the chip When the wafer is cut along a scribe line to form a single body, the cutting path cuts off at least an outer peripheral path portion connecting the constituent elements of the connection path to electrically separate the constituent elements. It is characterized by that.

According to the method of manufacturing a surface acoustic wave filter having such a structure, at the time of pattern formation, all the constituent elements (electrodes) are connected by the connecting paths formed at the same time and are electrically unified. As a result of being united, they have the same potential, and electrode destruction due to discharge is prevented.

Further, at the time of dicing for cutting the wafer along the scribe line in order to form a single chip serving as a surface acoustic wave filter, at least between the constituent elements in the pattern of the connecting path connecting the respective electrodes. Since the outer peripheral path portion to be connected is cut off, it is possible to electrically separate the above-mentioned constituent elements without adding a separate step of deleting the connection path, and to prevent the filter characteristics from being adversely affected. it can.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows one aspect of a manufacturing process of a surface acoustic wave filter according to the present invention. In the figure, on the piezoelectric substrate (wafer) 1 which can be divided into a large number of chips as a surface acoustic wave filter, as in the conventional one shown in FIG. The IDT electrodes 3 and 4, the REF electrode 5 and the scribe pattern are formed by patterning with a mask and evaporating aluminum, and are connected to the outer peripheral side of the constituent elements (IDT electrodes 3, 4 and REF electrode 5). The pattern of the connecting path 10 to be formed is patterned by using the same mask, and aluminum is formed by vapor deposition.

The connection path 10 connects the IDT electrodes 3 and 4 and the REF electrode 5, which are constituent elements of the surface acoustic wave filter, with the extraction paths 11, 11 ... U-shaped outer peripheral route 1 routed to the outermost periphery
2 and is formed by a cutting path 20 (indicated by a long broken line) during dicing for cutting the wafer 1 along the scribe lines connecting the scribe patterns 6, 6, 6, 6 to form the single chip 2. Of the connection path 10, the outer peripheral path 12 connecting the constituent elements (IDT electrodes 3, 4, REF electrode 5) and a part of the extraction path 11 are cut off.

That is, since the cutting path 20 formed by a normal dicing blade (cutting blade) has a width α capable of reliably cutting off the outer peripheral path 12 part and a part of the drawing path 11, the connecting path is formed. If the pattern forming position of 10 (in particular, the outer peripheral path 12) is set in advance to a portion which becomes the cutting path 20, the wafer 1 is cut along the wafer 1 without adding a cutting step separately. A portion that connects at least the constituent elements 3 and 4 at the time of dicing (12 peripheral passages)
Can be excised.

The scribe patterns 6, 6, 6, 6
Are formed by patterning with a mask in the same step as the IDT electrodes and the like.

According to the method of manufacturing a surface acoustic wave filter having such a structure, all the constituent elements (IDT electrodes 3 and 4, REF electrode 5) are connected by the connecting path formed at the same time when the pattern is formed. As a result, they are electrically united into one and have the same potential, and electrode destruction due to discharge is prevented.

Further, the wafer 1 is scribed with a scribe pattern 6 so as to form a single chip 2 which serves as a surface acoustic wave filter.
At the time of dicing for cutting along the scribe line connecting 6, 6, and 6, at least the constituent elements 3, 4, and 5 in the pattern of the connecting path 10 connecting the constituent elements 3, 4, and 5 are connected. Since the outer peripheral passage 12 is cut off, the constituent elements 3, 4, 5 can be electrically independent without any additional step of removing the connecting passage 10, and the filter characteristics are not required. It can be prevented from having an adverse effect.

[0014]

As can be understood from the above description, according to the method of manufacturing the surface acoustic wave filter of the present invention, all the constituent elements (electrodes) are connected by the connecting path at the time of pattern formation, and the same potential is obtained. Therefore, in the process of forming a pattern such as an electrode which is a component of the surface acoustic wave filter on the piezoelectric substrate (wafer), even if static electricity may be generated due to mechanical friction or temperature change, It is possible to prevent discharge between adjacent electrodes, it is possible to prevent the electrodes from being broken, and the yield and quality can be improved. Further, the wafer is formed so as to form a single chip that serves as a surface acoustic wave filter. At the time of dicing for cutting along the scribe line, at least the outer peripheral path portion connecting the above-mentioned constituent elements of the pattern of the connection path connecting each electrode is cut off. Since the can so without requiring the adding separately connecting channel deletion process, resulting electrically made independent of the component, not any adverse effect on the filter characteristics.

[Brief description of the drawings]

FIG. 1 is a view showing one aspect of a manufacturing process of a surface acoustic wave filter according to the present invention.

FIG. 2 is a view showing one aspect of a conventional manufacturing process of a surface acoustic wave filter according to the present invention.

[Explanation of symbols]

 1 Wafer (Piezoelectric Substrate) 2 Chip Single Unit 3,4 IDT Electrode 5 REF Electrode 6 Scribing Pattern 10 Connection Path 11 Extraction Path 12 Peripheral Path 20 Cutting Path

Claims (1)

[Claims] 1. When forming a pattern of a plurality of electrodes or the like, which are constituent elements of a surface acoustic wave filter, on a wafer that can be divided into a large number of chips that serve as a surface acoustic wave filter, the pattern is formed on the outer peripheral side of the constituent elements. When forming a pattern of connecting paths connecting them and cutting the wafer along the scribe line to form the chip alone, the cutting path forms an outer peripheral path connecting at least the constituent elements of the connecting paths. A method of manufacturing a surface acoustic wave filter, characterized in that a part is cut off to electrically separate the constituent elements.