JP2009088699A - Manufacturing method of piezoelectric device and piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a piezoelectric device and a piezoelectric device capable of easily obtaining a structure which prevents chipping or cracking. <P>SOLUTION: The manufacturing method of the piezoelectric device is provided with: a piezoelectric element mounting process for mounting a plurality of piezoelectric elements on a mounting board; a board joint process for joining a cover board to the mounting board in such a way as storing and sealing the respective piezoelectric elements in individual spaces; a divided groove forming process for forming divided grooves in a cross section almost V shape for individuation every piezoelectric element on the surface of the mounting board and the cover board; and a division individuation process for performing division by a line connecting a divided groove bottom part of one of the boards formed on the surface of the mounting board and the cover board and a divided groove bottom of the other board so as to perform individuation. Thus, the piezoelectric device can prevent chipping or cracking. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a piezoelectric device and a piezoelectric device.

  Many of the recent electronic devices have a microcontroller or the like in their control unit, and a piezoelectric device such as a piezoelectric vibrator or a piezoelectric oscillator is an indispensable electronic component for generating the reference clock.

  Among electronic devices, cellular phones, in particular, require high-density mounting of electronic circuit boards for miniaturization and high functionality, and electronic components such as piezoelectric devices used therefor are constantly required to be miniaturized. .

  For example, a piezoelectric oscillator generally has a structure in which a piezoelectric vibrating piece and an oscillation circuit are housed in a ceramic package and hermetically sealed with a lid made of metal or glass. For this reason, due to the limitation of the size reduction of the oscillation circuit and the restriction of the strength of the package for housing the oscillation circuit, the size reduction by the current general configuration is approaching the limit.

  In view of the situation as described above, Patent Document 1 discloses a piezoelectric vibrator that realizes a small size and a low profile and a manufacturing method thereof. In the invention disclosed in Patent Document 1, a plurality of piezoelectric elements are mounted on a wafer-like substrate, and a wafer-like lid substrate in which a recess is formed corresponding to each piezoelectric element is joined to the substrate, and then separated into individual pieces. A small piezoelectric vibrator is obtained.

  FIG. 3 is a cross-sectional view showing a manufacturing process of a conventional piezoelectric vibrator. First, a plurality of piezoelectric elements 11 are mounted on a mounting pattern 13 provided on one main surface of the substrate wafer 12. The mounting pattern 13 is electrically connected to the external mounting pattern 14 via a lead pattern (not shown) made of a through hole or the like. (Fig. 3 (a))

  After mounting the piezoelectric element 11, a lid wafer 16 having a plurality of recesses 15 is prepared and bonded to the substrate wafer 12 so that the piezoelectric element 11 is accommodated in the recess 15. As the bonding means, metal fusion bonding performed through a metal film applied to the bonding surface, direct bonding performed by using the same material for the substrate wafer and the lid wafer and planarizing each bonding surface, or the like is used. (Fig. 3 (b))

  After the substrate wafer 12 and the lid wafer 16 are joined, the piezoelectric vibrator 17 is completed by dicing at a predetermined position (cutting line in FIG. 3B) and dividing the wafer into individual pieces. (Fig. 3 (c))

JP 2006-339896 A

  However, the piezoelectric device manufactured by the above-described conventional manufacturing method is a box-shaped chip having a rectangular shape in plan view, and is manufactured while leaving corners on the outer peripheral portion thereof. In such a configuration, an impact applied by dropping or the like, and chipping or chipping at a corner portion are likely to occur during mounting on an external substrate, leading to a decrease in reliability as a product.

  As countermeasures against chipping and chipping, the chip corners may be processed and chamfered in advance, but the chiped device is very small, and chamfering of the corners is performed after the chip formation. This involves very difficult work, and if this is carried out, an increase in man-hours and an increase in cost are inevitable.

  In view of the above problems, an object of the present invention is to provide a piezoelectric device manufacturing method and a piezoelectric device that can easily obtain a structure that prevents chipping, chipping, and the like.

  A mounting substrate on which a plurality of piezoelectric elements are mounted; and a lid substrate that is bonded to the mounting substrate and accommodates and seals each of the plurality of piezoelectric elements in a separate space. The mounting substrate and the lid substrate are bonded to each other. After that, a piezoelectric device manufacturing method for obtaining individual piezoelectric devices by dividing each piezoelectric element, wherein at least a piezoelectric element mounting step for mounting the piezoelectric element on the mounting substrate, and the lid on the mounting substrate A substrate bonding step for bonding the substrate so that each of the piezoelectric elements is accommodated and sealed in a separate space, and a cross section for separating each piezoelectric element on the surface of the mounting substrate and the lid substrate A dividing groove forming step for forming a substantially V-shaped dividing groove, and a line connecting the dividing groove bottom of the one substrate and the dividing groove bottom of the other substrate formed on the surface of the mounting substrate and the lid substrate; Divide and divide into pieces And extent, the method for manufacturing a piezoelectric device comprising a.

  The dividing groove forming step is a method for manufacturing a piezoelectric device that is performed before the piezoelectric vibrating element mounting step for the mounting substrate side and before the substrate bonding step for the lid substrate side.

  The division groove forming step is a method for manufacturing a piezoelectric device that is performed after the substrate bonding step on both the mounting substrate side and the lid substrate side.

  The mounting substrate and the lid substrate are made of silicon, which is a piezoelectric device manufacturing method.

  The dividing groove forming step is a method for manufacturing a piezoelectric device formed by etching.

  One of the mounting substrate and the lid substrate is a flat substrate, and the other is constituted by a substrate having a concave portion for accommodating the piezoelectric element, and the piezoelectric device is accommodated in the concave shape space. Thus, a manufacturing method of a piezoelectric device to be joined is provided.

  A piezoelectric device manufactured by the manufacturing method, wherein the outer peripheral corner portion of the piezoelectric device is chamfered.

  According to the present invention, a piezoelectric device having a chamfered outer peripheral corner portion of the piezoelectric device can be manufactured without man-hours and costs, and a piezoelectric device having a structure that prevents chipping and chipping can be easily obtained.

  A piezoelectric element mounting step of mounting a plurality of piezoelectric elements on a mounting substrate; a substrate bonding step of bonding the lid substrate to the mounting substrate so that each of the piezoelectric elements is housed and sealed in a separate space; and the mounting A split groove forming step of forming a split groove having a substantially V-shaped cross section for separating each piezoelectric element on the surface of the substrate and the lid substrate, and forming on the surface of the mounting substrate and the lid substrate And a divided singulation step of dividing the substrate into pieces by dividing the divided groove bottom of the one substrate from the divided groove bottom of the other substrate. As a result, a piezoelectric device having a structure in which chipping or chipping is prevented is obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are diagrams showing a manufacturing process of a piezoelectric device according to the present invention, in which FIG. 1A shows a state before a mounting substrate and a lid substrate are joined, and FIG. 1B shows a state where the mounting substrate and the lid substrate are joined. (C) shows a state of being divided for each piezoelectric element. FIG. 2 is a partial top view of a lid substrate according to the method for manufacturing a piezoelectric device of the invention.

  Reference numeral 1 is a mounting substrate, and 2 is a lid substrate. The mounting substrate 1 is provided with a plurality of recesses 1a in a matrix, which serves as a region for accommodating and arranging the piezoelectric elements 3 individually. The piezoelectric element 3 is formed with excitation electrodes (not shown) on the front and back surfaces and connection electrodes (not shown) for external connection connected thereto. These electrodes are formed by means such as metal vapor deposition. After mounting the piezoelectric element 3 on the mounting substrate 1, the lid substrate 2 is joined, and the piezoelectric element 3 is hermetically sealed in the recess 1a. Finally, each piezoelectric device is completed by dividing each piezoelectric element 3. The general flow of the manufacturing process is the same as that of the prior art, but will be described in detail along the manufacturing process.

  First, the mounting substrate 1 and the lid substrate 2 are prepared, and the divided grooves 1b and 2a having a V-shaped cross section are formed on the surfaces opposite to the bonding surfaces of the both substrates. As shown in FIG. 2, the dividing groove 2 a is provided so as to extend on a dividing line when being separated. The dividing groove 1b is also formed so as to be in a positional relationship facing the dividing groove 2a. Note that the portion indicated by a broken line in FIG. 2 indicates the positional relationship of the piezoelectric element 3 and the like when bonded to the mounting substrate 1.

  The dividing grooves 1a and 2a can be easily formed by machining or etching using a dicing saw or the like. When the etching method is used, the mounting substrate 1 and the lid substrate 2 are made of silicon, and, for example, a V-groove with an apex angle of 70 ° can be easily formed by crystal anisotropic etching of silicon using a crystal orientation 1.0.0 plane. Can be formed.

  Subsequently, the piezoelectric element 3 is mounted in the recess 1 a of the mounting substrate 1. An electrode pad 4 is provided in the recess 1 a, and a connection electrode (not shown) of the piezoelectric element 3 and the electrode pad 4 are fixed through a conductive adhesive 5. The electrode pad 4 is connected to an external terminal 6 provided outside the mounting substrate 1 through a through hole (not shown).

  Subsequently, the lid substrate 2 is joined above the mounting substrate 1 on which the piezoelectric elements 3 are mounted so as to accommodate and seal each of the piezoelectric elements 3 in individual spaces. Further, the divided grooves 1b formed on the mounting substrate 1 and the divided grooves 2a formed on the lid substrate 2 are aligned and joined so as to face each other. The bonding means is performed by metal fusion bonding performed through a metal film applied to the bonding surfaces, direct bonding performed by flattening each bonding surface, or the like.

  Subsequently, the substrate is divided by a line (cut line in FIG. 1) connecting the divided groove bottom of the one substrate to the divided groove bottom of the other substrate formed on the surface of the mounting substrate 1 and the lid substrate 2. Divide into pieces. Division into individual pieces can be performed using a laser dicer or the like.

  The piezoelectric device manufactured through the above-described steps is completed with a configuration in which corner portions are chamfered inevitably because the outer peripheral portion thereof is located at a position corresponding to the inclined portion of the V-shaped dividing groove. The piezoelectric device thus configured can prevent chipping, chipping, and the like.

  Note that the formation of the dividing groove in the manufacturing process described above can also be performed after the mounting substrate 1 and the lid substrate 2 are joined.

  Further, the mounting substrate 1 employed in the description of the manufacturing process described above is a substrate having a concave portion and the lid substrate 2 is described as a flat substrate, but the mounting substrate 1 is a flat substrate and the lid substrate 2 is concave. It is good also as a board | substrate which has a part.

It is sectional drawing which shows the manufacturing process of the piezoelectric device of this invention, (a) is a figure which shows the state before a mounting board | substrate and a lid | cover board | substrate are joined, (b) is the state where the mounting board | substrate and the lid | cover board | substrate were joined. The figure shown, (c) is a figure which shows the state divided | segmented for every piezoelectric element. FIG. 2 is a top view of a lid substrate according to the method for manufacturing a piezoelectric device of the invention. Sectional drawing which shows the manufacturing process of the conventional piezoelectric vibrator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounting substrate 1a Concave 1b Dividing groove 2 Lid substrate 2a Dividing groove 3 Piezoelectric element 4 Electrode pad 5 Conductive adhesive 6 External terminal 11 Piezoelectric element 12 Substrate wafer 13 Mounting pattern 14 External mounting pattern 15 Concave 16 Lid wafer 17 Piezoelectric vibrator

Claims (7)

A mounting substrate on which a plurality of piezoelectric elements are mounted; and a lid substrate that is bonded to the mounting substrate and accommodates and seals each of the plurality of piezoelectric elements in a separate space. The mounting substrate and the lid substrate are bonded to each other. After that, a piezoelectric device manufacturing method for obtaining individual piezoelectric devices by dividing each piezoelectric element,
at least,
A piezoelectric element mounting step of mounting a piezoelectric element on the mounting substrate;
A substrate bonding step of bonding the lid substrate to the mounting substrate so as to accommodate and seal each of the piezoelectric elements in a separate space;
On the surface of the mounting substrate and the lid substrate, a split groove forming step of forming a split groove having a substantially V-shaped cross section for individualization for each piezoelectric element;
A split singulation step for dividing and dividing into pieces by a line connecting a split groove bottom of the other substrate from a split groove bottom of the one substrate formed on the surface of the mounting substrate and the lid substrate;
A method for manufacturing a piezoelectric device comprising:   2. The piezoelectric device according to claim 1, wherein the dividing groove forming step is performed before the piezoelectric vibrating element mounting step for the mounting substrate side and before the substrate bonding step for the lid substrate side. Device manufacturing method.   The method for manufacturing a piezoelectric device according to claim 1, wherein the dividing groove forming step is performed after the substrate bonding step on both the mounting substrate side and the lid substrate side.   The method for manufacturing a piezoelectric device according to claim 1, wherein a material of the mounting substrate and the lid substrate is silicon.   The method for manufacturing a piezoelectric device according to claim 4, wherein the dividing groove forming step is formed by etching.   One of the mounting substrate and the lid substrate is a flat substrate, and the other is composed of a substrate having a concave portion for accommodating the piezoelectric element, and the piezoelectric element is accommodated in the concave portion space. The method for manufacturing a piezoelectric device according to claim 1, wherein the piezoelectric device is bonded as described above.   A piezoelectric device manufactured by the manufacturing method according to claim 1, wherein an outer peripheral corner portion of the piezoelectric device is chamfered.

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