JPS60107909A - Manufacture of oscillating element - Google Patents

Abstract

PURPOSE:To reinforce the adhesion between a chip and terminal electrodes and reduce spurious phenomena by beveling facing terminals of a piezoelectric chip where terminal electrodes are formed, and then forming facing electrodes on main facing surfaces of the chip and said terminal electrodes. CONSTITUTION:An oscillating element 21 is formed by forming the facing electrodes 23 on the main facing surfaces of the chip 22 which is rectangular in plane view respectively and then forming terminal electrodes 24 for external connections at the lengthwise terminal parts. Said terminal parts are beveled piror to the formation of the electrodes 23 to form slanting surfaces 22a. Then, the terminal electrodes of the oscillating element are beveled and formed at the terminal parts of the oscillation chip, so the adhesive strength between the chip and terminal electrodes is increased enough to withstand a thermal shock, and reflected elastic waves are refracted on the chip end surfaces, thereby reducing spurious radiation.

Description

DETAILED DESCRIPTION OF THE INVENTION +1) Technical Field of the Invention The present invention relates to a method for manufacturing a vibrating element, and particularly to a method for improving the adhesion of terminal electrodes formed at the end of a chip.

fb) Background of the technology A vibrating element formed by forming appropriate patterned electrodes on the opposing main surfaces of a piezoelectric chip is such that when an alternating current electric field is applied to the electrodes I, the chip generates a stress of +61 wave number equal to the applied electric field, and When the frequency of the applied electric field matches the natural frequency of the chip, resonance occurs and strong vibrations are obtained.

FIG. 1 is a perspective view showing an example of the configuration of a vibrating element.The vibrating element 1 is made of a piezoelectric material such as LiNbO, and has a chip 2 cut out from a wafer, with one opposing electrode 3 on the opposing main surface.
1, and an external 4d connecting terminal crown pole 6 consisting of conductor layers 4 and 5 is formed at each end in the longitudinal direction.
Note that the facing portion 3 has a lead pattern 3a extending from one side of the main part, and each lead pattern 3a is connected to a different terminal electrode tVc.

(C) Prior art and problems - In the case of a large-sized vibrating element, after cutting out a chip, a counter electrode and a terminal electrode are individually formed. Dimensions are 5+
Small pieces, such as those with a thickness of about 500 mm and a thickness of about 500 mm, are manufactured in large numbers at intervals using photolithographic technology and screen printing technology.

FIG. 2 is a diagram for sequentially explaining the main steps of a conventional method for producing a plurality of vibrating elements from one wafer using photophosphorographic technology and screen printing technology.

In Part 21 (A), LiNb0.
Wafer 1 made from a single crystal of LiTa03v+
AujN? 12 is deposited.

Next, as shown in FIG. 2(b), AuM12 was selectively etched and dissolved away using photolithographic technology.
Ladder-shaped A with multiple opposing 7-8 immortals 3 connected in two rows
U pattern 13, that is, a pattern 13 in which a plurality of pairs of electrodes 3 forming 21 connected to the lead-out patterns 3a/i facing each other are connected in a direction orthogonal to the lead-out pattern 3a at each electrode main part.
to form. However, the patterns 13 formed on the front and back surfaces of the wafer 11 are provided in the same direction and in a staggered pattern when viewed from the side, and the portions of the patterns 13 that correspond to the electrode main portions face the front and back sides of the wafer 11.

Next, as shown in Fig. 2 (c) of the wafer 11, the conductor patterns 14, which will become the dedicated layer 4 on the opposite main surface of the wafer 11, are formed facing each other by screen printing technology, that is, the plurality of conductor layers 4 are formed in the width direction and the length direction. A strip-like pattern 141 connected to the longitudinal center of the Au pattern 13 and the wafer main surface V on the opposite side are formed to face each other.

Next, along the center line of the conductor pattern 14,
And when the Au pattern 13 is cut by dicing along the connection line of the electrode main part, as shown in FIG. 2),
A chip 1a is completed in which a pair of opposing electrodes 3 and two pairs of conductor layers 4 are formed on the chip 2.

The vibrating element 1a created in this way is mounted on the substrate of the square package, and the vibrating element 1a is mounted on the board of the chip 2.
The pair of conductor layers 4 may be connected by the conductive contact for mounting, but as shown in FIG. By completing the vibrating element 1, the chip 2 can be made smaller and the energy attenuated at the end face can be reduced.

However, the main surfaces of the wafers 7 and 110 facing each other are finished with a mirror surface, and the conductor layer 4 formed on the mirror surface has insufficient adhesive strength and is difficult to increase the adhesive area, so it does not move due to thermal shock. 1. fdl OBJECT OF THE INVENTION An object of the present invention is to provide a vibrating element f that eliminates the above-mentioned problems.

tel The purpose of the invention is to process the opposing end of the piezoelectric chip where the terminal η1 and the pole are formed, and then process the opposing main surface of the chip...'
This is achieved by a method for manufacturing a vibrating element characterized by forming 11 and M'i notes.

Embodiments of the Invention Below, a vibrating element according to an embodiment of the present invention will be explained with reference to the drawings.

FIG. 3 is a side view showing an example of a vibration resonator made by the method of the present invention, FIG. 4 is a cross-sectional view showing an example of a grindstone for chamfering the end face of a chip, and FIG. 5 is a vibration element shown in FIG. 3. Mass production example'f
: Rust, for clarity, is a VC diagram showing the entire process order of the main process.

In FIG. 3, the vibrating element 21 has opposing electrodes 23 formed on opposing main surfaces of a chip 22 that is rectangular in plan view, and a terminal electrode 24 for external connection is provided at the longitudinal end of the rectangle. However, prior to forming the electrode 23, the end portion is chamfered to form a slope 22a.

Note that the chamfering process may be performed on the upper surface edge and the lower surface edge of the chip 22 in separate processes, but as shown in FIG.
, or a diamond grindstone in which a groove 33 having a U-shaped cross section is formed as shown in FIG. 34f, if the width of the groove 33 is approximately the same as the thickness of the chip 22, the main surface near the end face of the chip 22 will be roughened by the grindstone 34 and chips from the chamfering process, and the terminal electrode 24 will be roughened. The adhesive strength will be strengthened.

In FIG. 5(a), a strip 41 cut from a wafer made of piezoelectric material has a width that is the same as the length of the chip 22 (for example, about 5 m), and a thickness of the strip 41. The thickness of the chip 22 is the same as, for example, 500/zm).

Therefore, using a diamond grindstone as shown in FIG. 4, as shown in FIG. 5(b), the end faces of the strips 41 in the width direction are chamfered to form two pairs of slopes 42 by grinding.

Next, as shown in FIG.
T! ;+: An L-a tooth-shaped Au pattern 43 is formed by photolithographic technology, etc., but a part of the Au pattern 43 corresponding to the tip of the electrode lead pattern 23a (FIG. 3) is formed on the slope 42 and the side surface. 45 and a part of the opposite surface.

Next, as shown in FIG. 5), a pair of conductor layers 44t in which terminal electrodes 24 are connected in parallel are formed along the chamfered end surface of the strip 41 by screen printing technology. When the A1 pattern 43 is divided into each comb tooth as shown by the single point @ line and cut, several comb teeth are cut as shown in Fig. 3 (the figure shows 16
) vibrating elements 21 are completed at the same time. Note that the method of cutting the wafer into strips 41 and into the vibrating elements 21 is the same as the cutting method used in the conventional method.

tg+ Effects of the Invention As explained above, according to the method of the present invention, the terminal electrode of the vibration @11 element is chamfered and the adhesive force between the chip and the terminal electrode is Not only is it strengthened and can withstand conventional thermal shocks, but the chamfering refracts the reflection of elastic waves at the end face of the chip, which has an extremely significant effect in reducing spurious waves.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the configuration of a vibrating element, FIG. 2 is a diagram illustrating the main steps of the conventional method for mass-producing the vibrating element, and FIG. 3 is an example of a vibrating element according to the method of the present invention. The side view shown in FIG. 4 is the tip end v1 of the vibrating element shown in FIG. 3.
A sectional view showing the main parts of an example of a grindstone for chamfering.
FIG. 3 is a diagram showing the main steps for explaining an example of lid production of the vibrating element shown in the figure. In the figure, 1ela, 21 is a vibration element, 2.2
2 is a nap, 22a is a chamfered slope, 3.23 is a counter electrode, 3a, 23 & is a drawer turn, 6° 24 is a terminal...
'pole, 13.43 is a set of counter electrode turns, 14.
Reference numeral 24 indicates an aggregate pattern of terminal electrodes, and 41 indicates a strip.

Claims (2)

[Claims] (1) LiNb0. Opposing main surfaces of a chip cut out from a wafer made of piezoelectric material = vc''C form opposing leading patterns extending from one side, and one of the leading patterns is connected to the opposite end of the chip, respectively. In the oscillator element C, the terminal electrode of the chip 2 is
After chamfering the opposing end wells of the
A method for manufacturing a oscillating element, characterized by forming poles and terminals IL. (2) The wafer from which an accumulated number of chips are cut out in a matrix arrangement is cut into strips whose width is the length of the opposing ends, and the strips are cut into a plurality of strips after chamfering the end faces in the width direction. forming a terminal electrode with the opposing camellia of the pair;
A method for imitating a wave f# element described in a patent, characterized in that the above-mentioned chip is then cut.