JPH09331225A - Manufacture of surface acoustic wave filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously inspect a plurality of resonator sections formed on respective conductor patterns of a ladder type surface acoustic wave filter composed of the plurality of resonators. SOLUTION: Each conductor pattern 96 which constitutes a surface acoustic wave filter is provided with a positive electrode 5, a negative electrode 50, and a wiring pattern for inspection which respectively connects one of the comb-shaped electrodes and the other comb-shaped electrodes of resonator sections 4a, 4b, and 40a to a positive and a negative electrodes 5 and 50. The wiring pattern for inspection is constituted of a plurality of main lines 6, 60, and 61 which are respectively extended from the electrodes 5 and 50 along cutting-plane lines 8b, 8c, and 8d and a plurality of auxiliary lines 7, 70, and 72 respectively extended from the main lines 6, 60, and 61 to supply inspection voltages to the resonator sections 4a, 4b, and 40a. In an inspection process, a DC inspection voltage is applied across the electrodes 5 and 50 by respectively bringing a pair of probes for applying inspection voltage into contact with the positive and negative electrodes 5 and 50 of each conductor pattern 96.

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 ladder-type surface acoustic wave filter which is configured by connecting a surface acoustic wave resonator composed of a pair of comb-shaped electrodes facing each other to a series arm and a parallel arm, respectively. In particular, the present invention relates to an inspection step for inspecting for the presence or absence of an electrical short circuit between the comb-shaped electrodes in the resonator portion of the conductor pattern to be the surface acoustic wave filter.

[0002]

2. Description of the Related Art Generally, a surface acoustic wave filter is shown in FIG.
As shown in, the series line (3) and parallel line (3
It is configured by connecting a series resonator (4A) (4B) (4C) and a parallel resonator (40A) (40B) (40C) to 0A) (30B) (30C), respectively. As shown in FIG. 10, each series resonator (4A) (4B) (4C) has a pair of comb-shaped electrodes (41) (42) and a grid-shaped reflector (45) on the surface of a substrate (90) having piezoelectricity. ) (45) is formed. For the configuration of each parallel resonator (40A) (40B) (40C), see the series resonator.
It is the same as (4A) (4B) (4C).

In the method of manufacturing the surface acoustic wave filter, after forming a plurality of conductor patterns serving as surface acoustic wave filters on the wafer, the wafer is divided into conductor patterns to complete the surface acoustic wave filter. But
The surface acoustic wave filter cannot obtain a desired filter characteristic if at least one resonator among the plurality of resonators (4) and (40) forming the filter has an electrical short circuit between the comb-shaped electrodes. . Therefore, conventionally, after the conductor pattern forming step, a pair of probes of a wafer prober for continuity inspection are brought into contact with a pair of comb-shaped electrodes forming each resonator section, and a DC inspection voltage is applied between the comb-shaped electrodes. Then, the presence or absence of conduction between the comb electrodes is inspected for each resonator section. And
If at least one of the resonator parts formed in the conductor pattern has continuity between the comb-shaped electrodes, a defective mark is attached to the surface of the conductor pattern by a wafer prober, and After completing the inspection of the resonator part, the wafer is divided into conductor patterns to obtain a plurality of filters. Among these filters, the marked filter is rejected as a defective product.

[0004]

However, in the conventional manufacturing method, since the presence or absence of conduction between the comb-shaped electrodes is inspected for each resonator portion as described above, all resonances formed in each conductor pattern are examined. There is a problem that it takes a long time to inspect the equipment. An object of the present invention is to provide a method of manufacturing a surface acoustic wave filter capable of simultaneously inspecting a plurality of resonator portions formed on each conductor pattern, and to reduce the time required for the inspection process.

[0005]

A method of manufacturing a surface acoustic wave filter according to the present invention is configured by connecting a surface acoustic wave resonator composed of a pair of comb-shaped electrodes facing each other to a series line and a parallel line, respectively. A method of manufacturing a ladder-type surface acoustic wave filter, comprising: forming a plurality of conductor patterns serving as surface acoustic wave filters on a wafer; and forming a resonance pattern as a part of the conductor pattern on the wafer. The inspection step of applying a DC inspection voltage between the pair of comb-shaped electrodes of the container portion to inspect whether there is continuity, and the dividing step of dividing the wafer into conductive patterns along a predetermined cutting line. There is.

The conductor pattern formed in the conductor pattern forming step has a positive electrode and a negative electrode to which a DC inspection voltage is to be applied, and one of the pair of comb-shaped electrodes of each resonator section is positive. And a wiring pattern for inspection for connecting the other comb-shaped electrode to the negative electrode. The inspection wiring pattern includes a plurality of main lines connected to the positive electrode and the negative electrode and extending on the same line as the cutting line, and 1 for extending the inspection line from each main line and supplying an inspection voltage to each resonator section. Alternatively, it is composed of a plurality of sub lines. still,
The main line is formed to overlap the cutting line at least in the region where the sub line extends. Then, in the inspection step, a pair of probes for applying an inspection voltage are brought into contact with the positive electrode and the negative electrode of each conductor pattern to inspect a plurality of resonator portions formed in each conductor pattern at the same time.

In the method of manufacturing a surface acoustic wave filter according to the present invention, when a DC inspection voltage is applied between the positive electrode and the negative electrode in the inspection step, all the resonator parts formed in the conductor pattern are The inspection voltage is simultaneously supplied between the comb electrodes. Here, when there is conduction between the positive electrode and the negative electrode, it is said that an electrical short circuit has occurred between the comb-shaped electrodes of at least one of the resonator parts formed in the conductor pattern. You can judge. In this way, all the resonator portions formed on the conductor pattern are inspected at the same time, so that the time required for the inspection process is shortened. Further, in the manufacturing method, since the main line is formed on the same line as the cutting line, the main line is cut off in the dividing step, and the sub lines are separated from each other. Therefore, even if these sub lines remain, they do not hinder the operation of the surface acoustic wave filter, and the filter characteristics are not adversely affected.

Specifically, the plurality of sub-lines that form the inspection wiring pattern are connected to a plurality of line pieces serving as the series line and the parallel line, or a plurality of pads used for connection with an external circuit. Among the two line pieces that are connected to each other with one arbitrary resonator part interposed therebetween, one line piece is connected to the positive electrode and the other line piece is connected to the negative electrode.

In the method of manufacturing a surface acoustic wave filter having the above-mentioned specific structure, when a test voltage is applied between the positive electrode and the negative electrode, the line piece positively charged and the line piece negatively charged are resonators. They will appear alternately with the parts in between. As a result, the inspection voltage is simultaneously supplied between the comb-shaped electrodes of all the resonator portions formed in the conductor pattern.

[0010]

According to the method of manufacturing a surface acoustic wave filter of the present invention, since the inspection voltage is simultaneously supplied between the comb-shaped electrodes of all the resonator portions formed in the conductor pattern, all of these resonances are generated. The parts can be inspected at the same time. As a result, the time required for the inspection process is shortened.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Two embodiments in which the present invention is applied to a method of manufacturing a ladder-type surface acoustic wave filter including three resonators and a ladder-type surface acoustic wave filter including six resonators will be described below. Will be specifically described with reference to the drawings. First Example In this example, a method of manufacturing a surface acoustic wave filter (91) including three resonators will be specifically described. FIG. 8 is a schematic diagram showing the structure of the surface acoustic wave filter (91), which includes an input terminal (11) and an output terminal.
Two series resonators (4A) and (4B) intervene in one series line (3) extending toward (12). Also, in the serial line (3),
In the series line between the series resonators (4A) and (4B), connect the ground terminal (2
The parallel line (30) extending toward (2) is connected, and the parallel line (3
One parallel resonator (40A) is interposed in 0). In addition, as shown in FIG. 10, each resonator (4A) (4B) (40A) has a pair of comb-shaped electrodes (41) (42) (43) (44) on the surface of a substrate (90) having piezoelectricity.
And a grid-shaped reflector (45) (45).

FIG. 1 shows the surface acoustic wave filter (91) of FIG.
It represents a basic conductor pattern formed on the.
The input pad (1), the output pad (10) and the ground pad (2) are respectively the input terminal (11) and the output terminal (1) shown in FIG.
2) and wire bonded to the ground terminal (22),
The surface acoustic wave filter (91) is packaged. still,
The series resonator part (4a) (4b) and the parallel resonator part (40
a) corresponds to the series resonators (4A) (4B) and the parallel resonator (40A) shown in FIG. 8, respectively, but the reflectors (45) (45) are not shown in FIG. .

In the method of manufacturing the surface acoustic wave filter (91) of this embodiment, first, a conductor pattern (96) having a predetermined pattern as shown in FIG. 2 is formed on a wafer (9) which is a substrate (90). Forming a plurality. In FIG. 2, one conductor pattern (96) is represented by a solid line, and the conductor pattern adjacent to the conductor pattern (96) is partially represented by a two-dot chain line. In addition, the first, second, third and fourth cutting lines (8a) (8b) (8c) (8d) shown by broken lines in the drawing are used in the later process
It is a cutting line when dividing (9), and each conductor pattern (9
6) is formed in the area surrounded by these cutting lines (8a) (8b) (8c) (8d). The conductor pattern (96) is partly the second cutting line with respect to the basic conductor pattern shown in FIG.
A positive electrode (5) formed on (8b) and a negative electrode (50) formed on part of the intersection of the third cutting line (8c) and the fourth cutting line (8d). The inspection wiring pattern is connected. The inspection wiring pattern is formed as shown in FIG. 2, and the first main line (6) extends from the positive electrode (5) on the same line as the second cutting line (8b), and the end of the first main line (6). A first sub-line (7) extends from there perpendicular to the second cutting line (8b). The termination of the first sub line (7) is made up of two series resonator parts (4a) (4
It is connected to a parallel line (30) extending from the middle of a series line (3) connecting b) to each other.

On the other hand, from the negative electrode (50), the second main line (60) and the third main line (61) orthogonal to each other are respectively the third cutting line (8c) and the fourth cutting line (8d). It extends on the same line. From the middle and end of the second main line (60) to the second sub line (70) and the third
The sub line (71) extends orthogonally to the third cutting line (8c). The ends of the second and third sub lines (70) and (71) are connected to the output pad (10) and the ground pad (2), respectively.
On the other hand, from the end of the third main line (61), the fourth sub line (72) is at the fourth
It extends perpendicularly to the cutting line (8d), and its end is connected to the input pad (1). Similarly, the adjacent conductor pattern shown by the two-dot chain line in FIG. 2 is also formed by overlapping a part of the inspection wiring pattern on the cutting line. For example, the third main line of the adjacent conductor pattern on the right side ( 61 ') extends on the same line as the second cutting line (8b) with a slight distance from the first main line (6). Further, the first main line (6 ') of the conductor pattern adjacent to the left side extends on the same line as the fourth cutting line (8d) and at a slight distance from the third main line (61). Furthermore, the second main line (60 ') of the conductor pattern adjacent to the upper side is the first cutting line.
It extends on the same line as (8a).

After forming a plurality of the conductor patterns (96) on the wafer (9), as shown in FIG. 7, the wafer (9) is placed on an inspection table (95) to form each conductor pattern (96). A pair of probes (94) (94) attached to the wafer prober (93) are brought into contact with the positive electrode (5) and the negative electrode (50), respectively, and the inspection voltage is applied between the electrodes (5) (50). Is applied. As a result, as shown in FIG. 2, the comb electrode (4) on the output side of the series resonator section (4a) is
2), the input side comb-shaped electrode (41) of the series resonator part (4b) and the input side comb-shaped electrode (43) of the parallel resonator part (40a) are positive, and the input side comb-shaped electrode of the series resonator part (4a) is The electrode (41), the output side comb-shaped electrode (42) of the series resonator part (4b), and the ground side comb-shaped electrode (44) of the parallel resonator part (40a) are negatively charged.

Here, when there is conduction between the positive electrode (5) and the negative electrode (50), at least one of the series resonator parts (4a) (4b) and the parallel resonator part (40a) is It can be determined that an electrical short circuit has occurred in one of the resonator parts. Therefore,
When there is conduction between both electrodes (5) and (50), a defective mark is attached to the surface of the conductor pattern (96) by the wafer prober (93).

Then, after conducting the same inspection on all the conductor patterns (96) on the wafer (9), the wafer (9)
Is divided into conductor patterns (96) along the cutting lines (8a) (8b) (8c) (8d) to obtain a plurality of surface acoustic wave filters (91).
Here, the first, second and third main lines (6) (60) (61) constituting the conductor pattern (96) are respectively the second, third and fourth cutting lines (8b) as shown in FIG. Since they are formed on the same line as (8c) and (8d), these main lines (6), (60) and (61) are cut off, and as shown in FIG. 3, each sub line (7) (70) (71) ( 72) will be separated from each other. In addition, two main lines formed on the same cutting line are simultaneously cut off by one cutting step along the cutting line. As described above, since the sub lines (7), (70), (71) and (72) are separated from each other, these sub lines remaining on the substrate (90) interfere with the operation as the surface acoustic wave filter. In addition, the filter characteristics are not adversely affected. Multiple filters (9
In 1), the filter (91) with the mark is excluded as a defective product.

Second Embodiment In this embodiment, a method of manufacturing a surface acoustic wave filter (92) including six resonators will be specifically described. FIG. 9 is a schematic diagram showing the structure of the surface acoustic wave filter (92), which includes an input terminal (11) to an output terminal.
Three series resonators (4A) (4B) (4C) are interposed in one series line (3) extending toward (12). In addition, the series line (3) is connected between the series resonators (4A) and (4B), between the series resonators (4B) and (4C), and between the series resonator (4C) and the output terminal (12). Respectively,
Three parallel lines (30A) (30B) (30C) extending toward the ground terminals (22) (23) (24) are connected. Each of these parallel lines (30A) (30B) (30C) has one parallel resonator (40A) (4A).
0B) and (40C) intervene. Each resonator (4A) (4B) (4C) (40A)
(40B) and (40C) are substrates having piezoelectricity as shown in FIG.
A pair of comb electrodes (41), (42), (43) and (44) and lattice-shaped reflectors (45) and (45) are formed on the surface of (90).

FIG. 4 shows the surface acoustic wave filter (92) of FIG.
It represents a basic conductor pattern formed on the.
The input pad (1), the output pad (10) and the ground pads (2) (20) (21) are respectively the input terminal (11), the output terminal (12) and the ground terminal (22) shown in FIG. The surface acoustic wave filter (92) is packaged by wire bonding with (23) and (24). The series resonator parts (4a) (4b) (4c) shown in FIG.
And the parallel resonator units (40a) (40b) (40c) are respectively the series resonators (4A) (4B) (4C) and the parallel resonators (40A) (40B) (40
Although it corresponds to C), illustration of the reflectors (45) and (45) is omitted in FIG.

In the conductor pattern forming step of this embodiment, a plurality of conductor patterns (97) having a predetermined pattern are formed on the wafer (9) to be the substrate (90) as shown in FIG. In FIG. 5, one conductor pattern (97) is represented by a solid line, and the conductor pattern adjacent to the conductor pattern (97) is partially represented by a two-dot chain line. Also, the first, second, third and fourth cutting lines (80a) shown by broken lines in the figure
(80b) (80c) (80d) are cutting lines when the wafer (9) is cut in a later step, and each conductor pattern (97) has these cutting lines (80a) (80b) (80c). It is formed in the area surrounded by (80d). The conductor pattern (97) includes a positive electrode (5) formed in the vicinity of the intersection of the first cutting line (80a) and the second cutting line (80b) with respect to the basic conductor pattern shown in FIG. Is formed by connecting the negative electrode (50) formed at the intersection of the third cutting line (80c) and the fourth cutting line (80d) and the inspection wiring pattern described later. The inspection wiring pattern is shown in Fig. 5.
The lead wire (65) extends from the positive electrode (5) toward the second cutting line (80b). The leader line (65) is the second
Terminate at the intersection with the cutting line (80b),
The main line (62) extends on the same line as the second cutting line (80b).
From the middle and end of the first main line (62), to the first sub line (73), the second
The sub line (74), the third sub line (75) and the fourth sub line (76) are the second cutting lines.
It extends perpendicular to (80b). First, second and fourth sublines
The ends of (73), (74) and (76) are connected to the input pad (1) and the ground pads (2) and (21), respectively. Also, the third sub line
The terminal of (75) is connected to the series line (3) that connects the two series resonator sections (4b) and (4c) to each other.

On the other hand, from the negative electrode (50), the second main line (63) and the third main line (64) orthogonal to each other are respectively the third cutting line (80c) and the fourth cutting line (80d). It extends on the same line.
A fifth sub line (77) and a sixth sub line (78) extend perpendicularly to the third cutting line (80c) from the middle and the end of the second main line (63).
The ends of the fifth and sixth sub lines (77) and (78) are connected to the ground pad (20) and the output pad (10), respectively. On the other hand, the seventh sub line (79) extends orthogonally to the fourth cutting line (80d) from the end of the third main line (64), and its end is
A series line connecting two series resonator parts (4a) and (4b) to each other
It is connected to (3). Similarly, the adjacent conductor pattern shown by the two-dot chain line in FIG. 5 is also formed by overlapping a part of the inspection wiring pattern on the cutting line, and for example, the third main line of the adjacent conductor pattern on the right side ( 64 ') is the second cutting line
It extends on the same line as (80b) with a slight distance from the first main line (62). Also, the first of the conductor patterns adjacent to the left side
The main line (62 ') extends on the same line as the fourth cutting line (80d) with a slight distance from the third main line (64). Further, the second main line (63 ') of the conductor pattern adjacent to the upper side is the first cutting line.
It extends on the same line as (80a).

After forming a plurality of the above-mentioned conductor patterns (97) on the wafer (9), the wafer (9) is set on the inspection table (95) as shown in FIG. 7 as in the first embodiment. An inspection voltage is applied between the positive electrode 5 and the negative electrode 50 of each conductor pattern 97 by the wafer prober 93. As a result, as shown in FIG. 5, the input side comb-shaped electrodes (4
1), output side comb-shaped electrode (42) of series resonator part (4b), input side comb-shaped electrode (41) of series resonator part (4c), ground side comb-shaped electrode (44) of parallel resonator part (40a) The input side comb-shaped electrode (43) of the parallel resonator section (40b) and the ground side comb-shaped electrode (44) of the parallel resonator section (40c) are positive, and the output side comb-shaped electrode of the series resonator section (4a).
(42), input side comb-shaped electrode (41) of series resonator part (4b), output side comb-shaped electrode (42) of series resonator part (4c), parallel resonator part (40a)
The input side comb-shaped electrode (43), the ground side comb-shaped electrode (44) of the parallel resonator part (40b), and the input side comb-shaped electrode (43) of the parallel resonator part (40c) are negatively charged. . Where the positive electrode
When there is conduction between (5) and the negative electrode (50), a defective mark is attached to the surface of the conductor pattern (97) by the wafer prober (93) by the same judgment as in the first embodiment.

Then, after conducting the same inspection on all the conductor patterns (97) on the wafer (9), the wafer (9)
Along the cutting lines (80a) (80b) (80c) (80d)
Divide into 7) to obtain a plurality of surface acoustic wave filters (92). Here, the first, second and third main lines (62) (63) (64) constituting the conductor pattern (97) are respectively the second, third and fourth cutting lines (80b) as shown in FIG. Since it is formed on the same line as (80c) (80d), these main lines (62) (63) (64) are cut off,
As shown in Fig. 6, the lead wire (65) and each sub wire (73) (74) (75) (76)
(77) (78) (79) will be separated from each other. In addition, two main lines formed on the same cutting line are simultaneously cut off by one cutting step along the cutting line. As described above, the lead wire (65) and each sub wire (73) (74) (75) (76) (7
7) (78) (79) are separated from each other, so that these leader lines and sublines remaining on the substrate (90) do not hinder the operation as a surface acoustic wave filter, and the filter characteristics There is no adverse effect on. Among the plurality of filters (92) thus obtained, the filter (92) with the mark is excluded as a defective product.

According to the first and second embodiments, when the inspection voltage is applied between the positive electrode (5) and the negative electrode (50) of the conductor patterns (96) (97), the conductor patterns (96) (97) Since the inspection voltage is simultaneously supplied to all the resonator parts formed in),
All these resonator parts can be tested simultaneously.
Therefore, one wafer (9) needs to be inspected a number of times corresponding to the number of conductor patterns (96) (97) on the wafer (9),
Compared with the conventional manufacturing method, in which each conductor pattern needs to be inspected multiple times and therefore one wafer is inspected many times, the number of inspections is significantly reduced and the time required for the inspection process is shortened. Will be done.

The above description of the embodiments is for explaining the present invention and should not be construed as limiting the invention described in the claims or reducing the scope.
In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

For example, in the above two embodiments,
The present invention is applied to a method of manufacturing a ladder-type surface acoustic wave filter including three or six resonators, but the present invention is applicable to all ladder-type surface acoustic wave filters including two or more resonators. It is possible to implement the manufacturing method.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic conductor pattern of a ladder-type surface acoustic wave filter including three resonators.

FIG. 2 is a diagram showing a conductor pattern formed in the first embodiment.

FIG. 3 is a plan view of a surface acoustic wave filter formed from the above conductor pattern.

FIG. 4 is a diagram showing a basic conductor pattern of a ladder-type surface acoustic wave filter including six resonators.

FIG. 5 is a diagram showing a conductor pattern formed in the second embodiment.

FIG. 6 is a plan view of a surface acoustic wave filter formed of the above conductor pattern.

FIG. 7 is a perspective view showing an inspection process in the first and second embodiments.

FIG. 8 is a schematic diagram showing a configuration of a ladder-type surface acoustic wave filter including three resonators.

FIG. 9 is a schematic diagram showing a configuration of a ladder-type surface acoustic wave filter including six resonators.

FIG. 10 is a plan view showing an electrode configuration of a resonator.

[Explanation of symbols]

 (1) Input pad (10) Output pad (2) Ground pad (3) Series line (30) Parallel line (4) Series resonator (40) Parallel resonator (5) Positive electrode (50) Negative electrode (6) 1st main line (60) 2nd main line (61) 3rd main line (7) 1st sub line (70) 2nd sub line (71) 3rd sub line (72) 4th sub line (8) Cutting line

Claims (3)

[Claims] 1. A method of manufacturing a ladder-type surface acoustic wave filter, comprising a surface acoustic wave resonator comprising a pair of comb-shaped electrodes facing each other connected to a series line and a parallel line, respectively. A conductor pattern forming step of forming a plurality of conductor patterns to be surface acoustic wave filters, and applying a DC inspection voltage between the pair of comb-shaped electrodes of the resonator portion formed as a part of the conductor pattern on the wafer. In the method of manufacturing a surface acoustic wave filter, which includes an inspection step of inspecting the presence or absence of electrical continuity and a division step of dividing the wafer into conductor patterns along predetermined cutting lines, the conductor pattern forming step is performed. The conductor pattern is composed of a positive electrode and a negative electrode to which a DC inspection voltage should be applied, and one of the pair of comb-shaped electrodes of each resonator part is connected to the positive electrode and the other comb-shaped electrode is connected. The test wiring pattern for connecting the shaped electrode to the negative electrode, the test wiring pattern is connected to each of the positive electrode and the negative electrode, and a plurality of main lines extending on the same line as the cutting line, It is composed of one or a plurality of sub-lines extending from the main line and supplying an inspection voltage to each resonator section. In the inspection step, a pair of probes for applying the inspection voltage to the positive electrode and the negative electrode of each conductor pattern. And a plurality of resonator portions formed on each conductor pattern are inspected at the same time, respectively, and a method for manufacturing a surface acoustic wave filter. 2. The main line is formed to overlap with the cutting line at least in a region where the sub line extends.
A method for manufacturing the surface acoustic wave filter according to item 1. 3. A plurality of sub-lines constituting an inspection wiring pattern are connected to a plurality of line pieces serving as the series line and the parallel line or a plurality of pads used for connection with an external circuit, and are arbitrarily connected. 2. The positive electrode is connected to one line piece and the negative electrode is connected to the other line piece of the two line pieces that are connected to each other with one resonator part of FIG. A method for manufacturing the surface acoustic wave filter according to item 1.