JP5288920B2 - Method for manufacturing element for crystal vibration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an element for a crystal oscillator capable of simply manufacturing a crystal chip to the edge of which bevel processing is performed. <P>SOLUTION: When the element for the crystal oscillator is manufactured, processes of: applying a resist film 20 to a wafer W, performing exposure and development to form a resist mask 21 for forming a bevel part 2 of the crystal chip 1; heating, softening the resist mask 21 to round the edge 22 of the resist mask 21; performing grinding processing by sand blast 15 to the wafer W to which the resist mask 21 is formed, and transferring the cross-sectional shape of the edge 22 of the resist mask 21 to the wafer W to form the bevel part 2 to the crystal chip 1 are performed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a technique for manufacturing a crystal resonator element in which an edge of a crystal piece is beveled.

  2. Description of the Related Art Conventionally, there is a crystal vibration element using a crystal piece having a so-called bevel shape in which a crystal piece is beveled and a chamfered outer edge. The purpose of providing this bevel shape is to prevent the crystal piece from being lost due to contact with the edge when assembling to the case, etc., concentrating the vibration energy at the center of the crystal piece, and setting the crystal impedence (CI) value. There are lowering, etc.

  There are, for example, the following three methods as a method of manufacturing the crystal piece of the crystal resonator element. In Patent Document 1, a plurality of rectangular AT plate crystal pieces are vertically arranged from an AT-cut crystal substrate, and each is bonded with an adhesive having low hardness, and the side surface of the rectangular AT plate crystal piece and an adhesive layer are bonded to the upper surface. A quartz crystal that forms an AT plate block that is alternately arranged, sprays abrasive grains from the top of the AT plate block, and performs bevel processing using the difference in the cutting speed between the adhesive layer and the rectangular AT plate crystal piece. A method for manufacturing a vibrator is described. Further, Patent Document 2 discloses a piezoelectric vibration element that uses a crystal anisotropy to form a chamfered portion at the edge of a crystal piece by etching and cuts the bottom of the chamfered portion to separate the crystal piece into pieces. A manufacturing method is described. Further, Patent Document 3 discloses a method of manufacturing a piezoelectric device in which a chamfered portion is formed by blasting by injecting abrasive grains, the chamfered portion is finished by etching, and then a crystal piece is separated into pieces by dicing to form a piezoelectric device. Have been described.

  On the other hand, in the case of obtaining a complicated bevel shape, the method of performing etching at the time of the bevel processing in Patent Document 2 and Patent Document 3 limits the bevel shape due to the anisotropy of the quartz crystal. It is necessary to perform bevel processing. However, in order to obtain a complicated bevel shape by this method, it is necessary to first form the crystal resonator element and separate it from the crystal substrate, and then rotate the crystal resonator element or tilt the abrasive grain injection angle. It was. In addition, in order to obtain a crystal piece having a bevel shape, it is necessary to perform two steps, a step of performing bevel processing on the edge of the crystal piece and a step of dividing the crystal piece into pieces. Due to the above two problems, the conventional manufacturing method has poor workability.

Japanese Patent Laid-Open No. 08-330876 (paragraph numbers 0018 to 0021) Japanese Unexamined Patent Publication No. 2003-110388 (paragraph numbers 0019 and 0020) JP 2007-165503 A (paragraph numbers 0034 and 0035)

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing a crystal resonator element capable of easily manufacturing a crystal piece having a beveled edge.

In the method for manufacturing a crystal resonator element of the present invention,
In a method of manufacturing a crystal resonator element by forming an electrode on a crystal piece formed from a crystal substrate,
Applying a resist film to a quartz substrate, performing exposure and development, and forming a resist mask for forming a bevel on the quartz piece;
Heating and softening the resist mask, rounding the edge of the resist mask;
Next, grinding with a blasting machine is performed on the quartz substrate on which the resist mask is formed, and a cross-sectional shape of the edge of the resist mask is transferred to the quartz substrate to form a bevel portion on the quartz piece. seen including,
The step of forming the resist mask is performed after the outer shape of the crystal piece is formed from the crystal substrate .

  According to the present invention, the resist mask formed on the quartz substrate is heated and softened, the edge of the resist mask is curved, and the quartz substrate is ground to change the curved shape of the edge to the edge of the quartz piece. I am trying to transcribe to. Therefore, it is possible to obtain a crystal piece having a bevel shape that approximates the shape of the edge of the resist mask at the edge only by performing grinding so as to cut the resist mask without tilting the crystal piece or the blasting machine. The step of forming the crystal piece from the crystal substrate can be performed with a blasting machine simultaneously with the formation of the bevel shape, and the number of steps can be reduced.

[First Embodiment]
A method for manufacturing a crystal resonator element according to an embodiment of the present invention will be described with reference to FIGS. First, as shown in FIG. 1A, a resist film 20 is formed on one surface 11 and the other surface 12 of the crystal wafer W forming the crystal piece 1 respectively. Next, as shown in FIG. 1B, the resist film 20 at a position corresponding to the edge of the crystal piece 1 is removed by photolithography, and a resist mask 21 is formed. As shown in FIG. 2, a plurality of sections 10 for forming the crystal piece 1 are provided on the wafer W, and a resist mask 21 for forming the crystal pieces 1 is formed in all the sections 10. . The cross-sectional view of the wafer W shown in FIG. 1 shows a cross section taken along the line AA shown in FIG.

  Next, as shown in FIG. 1C, the resist mask 21 is heated and softened at, for example, 150 ° C., which is not as high as the glass transition temperature, and the edge 22 of the resist mask 21 is rounded. The softened resist mask 21 is deformed by its own weight until it is in a state of being balanced with the surface tension, and spreads toward the quartz exposed region 24 of the resist mask 21. As a result, the edge 22 has a curved shape such that the rounded portion swells outward. In the present embodiment, since the edge portion 22 extends in the direction of the exposed region 24, the edge portion 22 is arranged so that the position of the edge portion of the crystal piece 1 to be formed matches the position of the tip of the edge portion 22 after deformation. Thus, the resist mask 21 is formed in consideration of the deformation amount, and thereby the crystal piece 1 having a desired size is formed.

  After the edge portion 22 is curved, as shown in FIG. 3, grinding is sequentially performed on one surface and the other surface of the wafer W by a sand blast 15 which is a kind of blast processing machine. The sand blast 15 has a plurality of nozzles 16 for emitting abrasive grains in the X-axis direction shown in the drawing, and the sand blast 15 is moved in the Z-axis direction while firing abrasive grains from all the nozzles 16 of the sand blast 15. Thus, it is possible to uniformly grind the wafer W on which the resist mask 21 is formed. Then, by grinding the one surface 11 and the other surface 12 of the wafer W, it is possible to simultaneously perform the external shape formation and bevel processing of the crystal piece 1 as shown in FIG.

  Next, the manner in which the crystal piece 1 is ground will be described in detail with reference to FIG. 4. When abrasive grains are supplied from the nozzle 16, the exposed region 24 and the resist mask 21 that are not covered with the resist mask 21 are ground. . In the present embodiment, the resist film 20 is made of a material whose grinding speed by the sandblast 15 is approximately 1: 1 compared with the grinding speed of quartz. For this reason, the crystal portion covered with the curved edge portion 22 is exposed by grinding the resist of the edge portion 22 and the curved shape of the edge portion 22 is transferred (FIG. 4). (A) thru | or FIG.4 (c)). Thereby, bevel processing is performed on a portion corresponding to the edge of the crystal piece 1 on one surface side of the wafer W, and the bevel portion 2 is formed.

  Thereafter, the wafer W is turned over and the other surface 12 is subjected to the same grinding process, so that one surface 11 and the other surface of the crystal piece 1 of the wafer W are shown in FIG. 1 (d) and FIG. 4 (d). The bevel portion 2 is formed at a position corresponding to the edge portion of the surface 12, and thereafter the outer shape of the crystal piece 1 is formed by grinding only to the position corresponding to the exposed region 24 by the sandblast 15 as shown in FIG. To complete. Thereby, the crystal piece 1 having a bevel shape in which the bevel portion 2 is formed at the edge portion is formed. The crystal piece 1 is formed in a state of being connected and supported on the wafer W by the connection support portion 25.

  Next, as shown in FIG. 5A, a metal film 34 and a resist film 35 are formed on the entire surface of the crystal piece 1 that is connected to and supported by the wafer W, as shown in FIG. ), A mask pattern of the metal film 34 corresponding to the shapes of the excitation electrodes 30 and 31 and the extraction electrodes 32 and 33 is formed on the entire surface of the crystal piece 1 by photolithography and etching with a KI solution. Then, the metal film 34 is etched as shown in FIG. 5C to form excitation electrodes 30 and 31 and extraction electrodes 32 and 33, and the resist film 35 is removed as shown in FIG. 5D. A crystal resonator element is formed. Then, the crystal support element 25 shown in FIG. 6 is formed by cutting the connection support portion 25 with the sandblast 15 to separate the crystal oscillator elements into individual pieces.

  As shown in FIGS. 6A and 6B, the crystal resonator element has an excitation electrode 30 formed on one surface 11a of the crystal piece 1 and an excitation electrode 31 formed on the other surface 12a. An extraction electrode 33 is connected to the extraction electrode 32 and the excitation electrode 31, respectively. The lead electrodes 32 and 33 extend from the one surface 11a on which the connected excitation electrodes 30 and 31 are formed and the other surface 12a to the side surface 14 on which the connection support portion 25 is formed. Is extended to one surface 11a and the other surface 12a that face each other. Therefore, the extraction electrodes 32 and 33 are formed to be aligned on the side surface 14.

  Next, a crystal resonator 70 using the crystal resonator element of the present embodiment will be described with reference to FIG. As shown in FIGS. 7A and 7B, the crystal resonator 70 is electrically connected to a pair of electrodes 72 provided in an exterior body (container) 71 with lead electrodes 32 and 33 of the crystal resonator element. It mounts by adhering in the aspect electrically connected with the adhesive agent 73. FIG. And the external electrode 74 and the electrode 72 provided in the lower part of the exterior body 71 are electrically connected via the wiring in the exterior body 71, By connecting this external electrode 74 with the electrode of an electronic device, The crystal resonator element is electrically connected to the electronic component.

  According to the present embodiment described above, the resist mask 21 formed on the wafer W is heated and softened, and the edge portion 22 is deformed into a curved shape bulging toward the outside. Grinding with sandblast 15 is performed uniformly. As a result, the shape of the edge 22 is transferred to the portion corresponding to the edge of the crystal piece 1 simply by grinding with the sandblast 15 so as to remove the resist mask 21, so that the crystal piece 1 and the sandblast 15 are not inclined. The crystal piece 1 having the bevel portion 2 that approximates the shape of the edge portion 22 formed at the edge portion can be formed. In this embodiment, since the bevel portion 2 is first formed by the sandblast 15, the quartz in the exposed region 24 is also cut accordingly. Therefore, it becomes possible to form the outer shape of the crystal piece 1 simultaneously with the formation of the bevel portion 2, and the crystal piece 1 having the bevel portion 2 formed on the edge portion can be easily formed only by grinding with the sand blast 15. The number of steps can be reduced.

  In the present invention, a resist mask is formed, the edge is curved by heating and softening the resist mask, the shape of the curved edge is transferred to the crystal piece by blasting, and the crystal piece and the blasting machine are Since the desired bevel portion is formed without tilting or rotating, the shape of the edge portion is changed on both the one surface and the other surface of the wafer so that the shapes of the bevel portions on the one surface and the other surface are different from each other. You can also In addition, the shape of the bevel portion is not necessarily a curved shape, and may be a planar shape. Since the shape of the bevel portion approximates the shape of the edge portion, it can be freely changed by changing the shape of the edge portion. Also, adjust the resist film thickness, viscosity, resist film material, heating conditions, etc. to adjust the shape of the edge so that the outer shape of the crystal piece is finished at the same time as the beveled parts on one side and the other side of the wafer are finished. May be adjusted. In the present embodiment, the resist pattern is formed of a material such that the grinding speed of the resist film and the grinding speed of the crystal are approximately 1: 1. However, as an embodiment of the present invention, the grinding speed of the resist film is as follows. Since the thickness of the resist film can be adjusted according to the ratio of the grinding speed of quartz and the quartz, a desired bevel portion can be formed regardless of the use of the resist film of any material.

[Second Embodiment]
Further, the embodiment of the present invention may be the embodiment shown in the second embodiment. A method for manufacturing the crystal resonator element of this embodiment will be described with reference to FIGS. The cross-sectional views of the wafer W1 shown in FIGS. 8 and 9 show the cross section taken along the line AA in FIG. 2 as in the first embodiment. First, as shown in FIG. 8A, a metal film 40 made of Cr (chrome) and Au (gold) and a resist film 41 are formed on one surface 11 and the other surface 12 of the wafer W1, respectively, and resist is formed by photolithography. The mask 42 is formed and the metal film 40 is etched with a KI (potassium iodide) solution to form an outer mask pattern 42 for forming the outer shape of the crystal piece 1 on both upper and lower surfaces of the wafer W1. Etching is performed by immersing the wafer W1 in a hydrofluoric acid solution to form the crystal piece 1 as shown in FIG. The crystal piece 1 is formed in a state of being connected and supported by the connection support portion 43 to the wafer W1 as in the first embodiment.

  Next, as shown in FIG. 8C, a metal film 44 and a resist film 45 are formed on the entire surface of the crystal piece 1 while being connected to and supported by the wafer W1, and photolithography and KI are performed. A mask pattern corresponding to the shapes of the excitation electrodes 30 and 31 and the extraction electrodes 32 and 33 is formed on the entire surface of the crystal piece 1 by etching with a solution. Then, as shown in FIG. 8D, the metal film 44 is etched so that the excitation electrodes 30 and 31 and the extraction electrodes 32 and 33 are formed in the same manner as the crystal resonator of the first embodiment. At the same time, the resist film 45 is removed to form a crystal resonator element.

  Next, as shown in FIG. 9A, a resist film 20 is formed on one surface 11 a and the other surface 12 a of the crystal resonator element so as to cover the excitation electrodes 30 and 31 and the extraction electrodes 32 and 33. Then, the resist film 20 is heated to round the edge 23 of the resist film 20. The softened resist mask 21 is deformed by its own weight until it is balanced with the surface tension, and spreads toward the edge of the crystal piece 1. And like 1st Embodiment, let the edge part 23 be a curved shape so that the rounded site | part may bulge outside.

  After curving the edge portion 23 of the resist film 20, the bevel portion 2 is formed on the outer edge of the crystal piece 1 as shown in FIG. By peeling off the resist film 20, a crystal resonator element having a bevel shape in which a bevel portion 2 is formed on the outer edge as shown in FIG. 9D is formed. Then, the crystal support element 43 shown in FIG. 10 is formed by cutting the connection support portion 43 with the sandblast 15 to separate the crystal oscillator elements. In the present embodiment, the cutting with the sandblast 15 is not performed so that the extraction electrodes 32 and 33 are not cut at the position where the extraction electrodes 32 and 33 are formed.

  Also in such an embodiment, a desired bevel portion 2 can be formed without tilting the crystal piece 1 or the sandblast 15 as in the first embodiment. Further, simultaneously with the formation of the bevel portion 2, it is possible to perform a process of separating the crystal resonator element from the wafer W1. Accordingly, the crystal resonator element having the bevel portion 2 formed on the edge portion can be formed by grinding with the sandblast 15. In the present invention, a resist mask is formed, the edge is curved by heating and softening the resist mask, the shape of the curved edge is transferred to the crystal piece by blasting, and the crystal piece and the blasting machine are Since a desired bevel portion is formed without tilting or rotating, when forming a crystal piece, a rectangular crystal piece is formed by sandblasting instead of etching to form an excitation electrode and an extraction electrode, thereby forming a crystal piece. A vibrator element may be formed.

It is explanatory drawing for demonstrating the manufacturing method of the crystal piece 1 which concerns on this embodiment. It is a top view of the wafer W for forming the crystal piece 1 which concerns on this embodiment. 4 is a perspective view for explaining the relationship between a wafer W and a sandblast 15; FIG. It is explanatory drawing for demonstrating the grinding process at the time of formation of the crystal piece. It is explanatory drawing for demonstrating the manufacturing method of the element for crystal oscillators of this embodiment. It is a perspective view for demonstrating the element for crystal oscillators of this embodiment. It is explanatory drawing for demonstrating the crystal oscillator which concerns on this embodiment. It is the 1st explanatory view for explaining the manufacturing method of crystal piece 1 concerning a 2nd embodiment. It is 2nd explanatory drawing for demonstrating the manufacturing method of the crystal piece 1 which concerns on 2nd Embodiment. It is a perspective view for demonstrating the element for crystal oscillators of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crystal piece 2 Bevel part 10 Section 11, 11a One side 12, 12a Other side 15 Sand blast 16 Nozzle 20 Resist film 21 Resist mask 22, 23 Edge 24 Exposed area | region 25, 43 Connection support part 30, 31 Excitation electrode 32, 33 Pull-out Electrode 34, 44 Metal film 35, 45 Resist film W, W1 Wafer

Claims (1)

In a method of manufacturing a crystal resonator element by forming an electrode on a crystal piece formed from a crystal substrate,
Applying a resist film to a quartz substrate, performing exposure and development, and forming a resist mask for forming a bevel on the quartz piece;
Heating and softening the resist mask, rounding the edge of the resist mask;
Next, grinding with a blasting machine is performed on the quartz substrate on which the resist mask is formed, and a cross-sectional shape of the edge of the resist mask is transferred to the quartz substrate to form a bevel portion on the quartz piece. Including
The method of manufacturing a crystal resonator element, wherein the step of forming the resist mask is performed after an outer shape of a crystal piece is formed from a crystal substrate.

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