JP2003218420A - Method of manufacturing electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electronic component with high productivity. <P>SOLUTION: This manufacturing method comprises a first process of forming a plurality of electronic elements 13 on a surface of a board 1, a second process of cutting a groove 9 in the surface of the board 1 along the peripheries of the electronic elements 13, and a third process of removing a part of the board 1 from the rear as far as the groove 9 so as to separate the electronic elements 13 from each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing various electronic components, and more particularly to a method for manufacturing electronic components that are compatible with miniaturization.

[0002]

2. Description of the Related Art As a conventional method of manufacturing an electronic component, there are the following methods, for example.

That is, an element of an electronic component is an electronic circuit formed by sequentially laminating and patterning a material such as a metal, a dielectric or a semiconductor on the surface of a material on a flat plate such as a silicon substrate or a glass substrate. It was done,
Usually, in order to form a plurality of electronic elements at the same time, for example, a plurality of electronic elements are collectively formed on the surface of a silicon substrate, and then each electronic element is cut into individual pieces using a dicing blade or the like. is doing.

[0004]

According to the above manufacturing method, when miniaturizing electronic components, a thin substrate is used to collectively form electronic elements on the surface thereof, and then each electronic element is formed into a dicing blade or the like. Will be cut into individual pieces. However, since each electronic element is cut into individual pieces, there is a problem that productivity is poor as a result.

Therefore, an object of the present invention is to provide a method of manufacturing an electronic component with high productivity.

[0006]

In order to achieve this object, the invention according to claim 1 of the present invention comprises a first step of forming a plurality of electronic elements on the surface of a substrate, and a step of forming the electronic elements. A second step of forming a groove on the front surface side of the substrate along the outer circumference, and a third step of separating the plurality of electronic elements from each other by removing a part of the substrate from the back surface side of the substrate until the groove is reached. It is a method of manufacturing an electronic component having the steps of, and by removing a part of the substrate from the back surface side of the substrate, it is possible to separate the electronic elements formed on the substrate into individual pieces, so that the production can be performed efficiently. There is an effect that it can.

In addition, since the substrate has a sufficient thickness in the step of forming an electronic element on the substrate, the substrate is made to have a desired thickness by removing a part of the substrate from the back side of the substrate later. Even with a small-sized electronic element having a small thickness, cracking defects can be reduced, and as a result, it is possible to contribute to improvement in productivity.

In the second aspect of the invention, the second step is
The method of manufacturing an electronic component according to claim 1, further comprising: a step of forming a resist mask except a surface of the substrate on which the groove is formed, a step of performing dry etching, and a step of removing the resist mask. There is an effect that the groove can be efficiently formed on the surface of the substrate.

The invention according to claim 3 is the method of manufacturing an electronic component according to claim 2, wherein the step of removing the resist mask is performed after the third step, and the resist is used in the step of removing a part of the substrate. The electronic device under the mask can be protected from damage and contamination.

The invention according to claim 4 is the method of manufacturing an electronic component according to claim 2 or 3, wherein the dry etching is performed using at least two kinds of gas. Since the etching state can be changed depending on the type of gas, there is an effect that the shape of the groove can be controlled.

According to a fifth aspect of the invention, at least one type of gas used for dry etching is a gas that promotes etching, and the other at least one type is a gas that suppresses etching. It is a method of manufacturing a component, and by using a gas that promotes etching and a gas that suppresses etching, it is possible to partially strengthen or weaken the etching of the groove. It is a complement.

According to a sixth aspect of the present invention, etching is performed using a mixed gas of a gas that promotes etching and a gas that suppresses etching, and the gas that promotes etching is mixed as a groove is deeply dug from the surface of the substrate. The method for manufacturing an electronic component according to claim 5, wherein the etching is performed at a high ratio, and when the etching is strongly performed as the substrate is deeply dug, the inner angle between the bottom surface and the side surface of the groove becomes an acute angle. This has the effect of strengthening the bonding strength when the substrate and the dummy substrate are bonded via the adhesive layer in a later step, and in addition, in the step of removing a part of the substrate, grinding is performed. When performing, chipping is less likely to occur at the side surface of the groove and the corner portion of the ground surface.

According to a seventh aspect of the present invention, etching is performed by alternately switching between a gas that promotes etching and a gas that suppresses etching, and the gas that promotes etching is switched as the groove is dug deeper from the surface of the substrate. The method for manufacturing an electronic component according to claim 5, wherein etching is performed for a long time, and when the etching is strongly performed as the substrate is deeply dug, the inner angles of the bottom surface and the side surface of the groove are acute angles. The same effect as that of the sixth aspect is achieved.

The invention according to claim 8 is the method for producing an electronic component according to claim 2 or 3, wherein after dry etching is performed, xenon difluoride is further used as gas. When xenon difluoride is used as a gas for dry etching, it has an effect that it is possible to partially widen the inner wall of the groove, and chipping occurs during grinding in the step of removing a part of the substrate. This is effective when it is desired not to raise it or when it is desired to form the side surface of the groove perpendicular to the back surface of the substrate.

According to a ninth aspect of the present invention, as a method of removing a part of the substrate in the third step, a dummy substrate is used to connect at least the surface of the electronic element and the dummy substrate through an adhesive layer. The method of manufacturing an electronic component according to claim 1, wherein the back side of the substrate is ground, and the strength of the substrate is strengthened by connecting the dummy substrate, and a part of the substrate can be removed by grinding. Has the effect of facilitating. In addition, since the plurality of elements are separated from each other because they are connected by the adhesive layer, there is an effect that each electronic element can be easily taken out when mounted on the mounted body.

According to a tenth aspect of the present invention, there is provided a method of manufacturing an electronic component according to the ninth aspect, wherein an adhesive layer is formed on the surface of the electronic element and at least the outer peripheral surface of the electronic element. By forming it on the outer peripheral surface of the element, the electronic element is firmly bonded to the dummy substrate, and when grinding is performed to remove a part of the substrate from the back side of the substrate, the dummy substrate and the electronic element are prevented from shifting. As a result, there is an effect that the substrate can be removed uniformly.

Further, by forming an adhesive layer also on the side surface of the groove, the strength of the above-mentioned bonding is further improved, so that the above-mentioned function and effect can be further enhanced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing an electronic component of the present invention will be described below with reference to embodiments and the drawings. An angular velocity sensor was used as the electronic component.

FIG. 1 is a perspective view of an angular velocity sensor according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the same. A buffer layer 2, a lower electrode layer 3, a piezoelectric layer 4, an upper electrode layer 5, and an auxiliary electrode 6 are sequentially provided on a tuning fork-shaped substrate 1.

Now, the operation when the angular velocity sensor detects the angular velocity will be briefly described with reference to FIGS. 1 and 2.

The upper electrode layer 5 shown in FIGS. 1 and 2 is divided into an excitation electrode 5A and a detection electrode 5B, which face each other so as to sandwich the piezoelectric layer 4 together with the lower electrode layer 3. When a voltage is applied between the excitation electrode 5A and the lower electrode layer 3, the portion of the piezoelectric layer 4 sandwiched between the excitation electrode 5A and the lower electrode layer 3 expands and contracts, and thus the two arms provided on the substrate 1 The shapes of the parts 10A and 10B are distorted, and as a result, vibration occurs in the horizontal direction of the tuning fork. At this time, when an angular velocity about the direction parallel to the arm of the tuning fork is generated, the arm 10A,
Deflection occurs in 10B in a direction perpendicular to both the axis and the vibration direction. Since the piezoelectric layer 4 is charged according to the amount of this deflection, the magnitude of the angular velocity can be detected by detecting this amount of charge by the detection electrode 5B.

Next, the manufacturing method of the present embodiment will be described with reference to FIGS.

FIG. 3 is a diagram showing a flow of a method of manufacturing an angular velocity sensor according to the present embodiment, and FIGS. 4 to 20 are a sectional view and a perspective view showing a manufacturing process, respectively.

First, in FIG. 4, a buffer layer 2 made of any one of nickel oxide, cobalt oxide, magnesium oxide, and titanium is formed on the surface of the substrate 1 (FIG. 3).
A). As a forming method, a MOCVD method can be mentioned. For example, when the buffer layer 2 of nickel oxide is formed, it can be obtained by using a gas obtained by sublimating and vaporizing nickel acetylacetonate. When titanium is used, a sputtering method can be used in addition to the above method.

Next, the lower electrode layer 3 is formed on the surface of the buffer layer 2 in FIG. 5 (FIG. 3B). Pt is used as a material and is formed by a method such as sputtering or vacuum deposition.

Then, the piezoelectric layer 4 is formed on the surface of the lower electrode layer 3 in FIG. 6 (FIG. 3C). As the material, for example, a piezoelectric material such as lead zirconate titanate (hereinafter referred to as PZT) is used and is formed by sputtering.

Next, FIG. 7 shows that the upper electrode layer 5 was formed on the surface of the piezoelectric layer 4 by using gold as a material by a method such as sputtering or vacuum deposition (FIG. 3D). PZT here
The adhesion strength between the piezoelectric layer 4 and the upper electrode layer 5 can be further improved by forming a titanium or chromium layer between the piezoelectric layer 4 made of gold and the upper electrode layer 5 made of gold.
That is, the above materials have excellent adhesion to PZT, and
Since gold forms a strong diffusion layer, the adhesion strength can be improved. In the experiments by the inventors, for example, when titanium was used, sufficient adhesion could be obtained by forming a layer having a film thickness of about 20 to 100 Å.

Next, FIG. 8 to FIG. 16 show particularly the arm portions 10A, 1
0B shows a cross-sectional view.

First, in FIG. 8, the excitation electrode 5 of the upper electrode layer 5 is
A, the element forming resist film 7 is formed on the portion where the detection electrode 5B is formed (FIG. 3E). As a method of forming this, a general photolithography method using a photosensitive resin can be used.

Next, in FIG. 9, the upper electrode layer 5 and the piezoelectric layer 4 in the region other than the region covered with the element forming resist film 7 are removed by dry etching to remove the excitation electrode 5A.
And the detection electrode 5B is formed (FIG. 3F). At this time, the removal solvent used in the next step of removing the element forming resist film 7 and the lower electrode layer 3 are exposed to prevent the interface between the lower electrode layer 3 and the piezoelectric layer 4 from being attacked in a later step. The removal of the piezoelectric layer 4 is ended immediately before reaching the bottom surface of the piezoelectric layer 4 so as not to do so.

Then, the element forming resist film 7 is removed in FIG. 10 (FIG. 3G). As a result, the upper electrode layer 5 is separated into the excitation electrode 5A and the detection electrode 5B.

As a solvent for removing the element forming resist film 7, an organic solvent or an alkaline solution can be used. Also, a method such as oxygen ashing can be used.

Next, referring to FIG. 11, an element forming resist film 7 is formed.
A resist mask 8 is formed below the excitation electrode 5A, the detection electrode 5B, and the piezoelectric layer 4, which are covered with the above, so as to cover the surface portions of the excitation electrode 5A and the detection electrode 5B that remain outside from the vertical lower side (FIG. 3H). . At this time, the outer periphery of the resist mask 8 is not connected to any other electronic element 13 so that the individual electronic elements 13 are separated as shown in FIG. As a result, the following operational effects are achieved.
That is, since the resist mask 8 is not connected to the other electronic elements 13, the substrate 1 can be transferred from the back surface side of the substrate 1 in a later step.
When a part of is removed, the electronic element 13 is connected to the other electronic element 13 only through the adhesive layer 12 described later. Therefore, by removing the adhesive layer 12, the electronic elements 13 can be separated at once.

The method for forming the resist mask 8 is the same as that for the element forming resist film 7.

Subsequently, in FIG. 12, the piezoelectric layer 4, the lower electrode layer 3 and the buffer layer 2 are removed by dry etching (FIG. 3I).

Further, as shown in FIG. 13, the substrate 1 is dry-etched. At this time, dry etching uses at least two kinds of gases. The two kinds of gas are gases whose etching conditions change, and for example, SF ₆ is used as a gas for promoting etching and C ₄ F ₈ is used as a gas for suppressing etching.

At the time of etching, these gases are mixed at the same time, or the gases are alternately switched and gradually etched. When the gases are mixed at the same time, the suppression and promotion of etching are controlled by the mixing ratio, so that the etching does not progress or partially proceeds. If this is controlled well, the etching will proceed only vertically downward, and the inner angles of the bottom surface and the side surface of the groove 9 can be made substantially right angles.

Further, the inner angle between the bottom surface and the side surface of the groove 9 can be made acute by increasing the mixing ratio of the etching promoting gas as the etching progresses.

On the other hand, when these two kinds of gases are alternately switched to alternately switch the etching promotion and the etching suppression, the shape of the groove 9 can be similarly controlled by controlling the switching ratio.

Here, the etching amount of the substrate 1 is set to be larger than the finally required thickness of the substrate 1. In this way, as shown in FIG. 13, the back sides of the arms 10A and 10B have a trapezoidal shape with a narrower width.

Next, as shown in FIG. 14, the dummy substrate 11
And the substrate 1 are bonded (FIG. 3J). At this time, the substrate 1 without removing the resist mask 8 formed when forming the groove 9
And the dummy substrate 11 are bonded. That is, the resist mask 8 is not removed after the step of FIG. 13 and is connected to the dummy substrate 11 via the adhesive layer 12 as shown in FIG. After removing a part of the substrate 1 in a later step, the resist mask 8 is removed. At this time, if necessary, the residue of the adhesive layer 12 attached to the electronic element 13 is also removed.

According to the above manufacturing process, the upper electrode layer 5 forming the excitation electrode 5A and the detection electrode 5B is covered with the resist mask 8 until it is separated into individual electronic elements 13 in a later process. Therefore, damage and contamination of the upper electrode layer 5 can be reduced.

The step of removing the resist mask 8 (FIG. 3M) is attached to the dummy substrate 11 (FIG. 3).
It is also possible to do it before J).

The adhesive layer 12 is formed on the surface of the electronic element 13 and at least on the outer peripheral surface of the electronic element 13. Here, in order to further improve the bonding strength between the substrate 1 and the dummy substrate 11, it is desirable that the adhesive layer 12 sufficiently penetrates between the trapezoidal arms 10A and 10B (groove 9). After the adhesive layer 12 is fixed, the trapezoidal arms 10A and 10B are fixed so as to bite into the adhesive layer 12 as shown in FIG. 14, so that the bonding strength can be further improved.

Although FIG. 14 shows one of the electronic elements, in practice, as shown in FIG. 17, the dummy substrate 11 and the surface of the substrate 1 on which the electronic elements are formed face each other by the adhesive layer 12. It is fixed.

The dummy substrate 11 may be any one as long as it has a flat surface and is strong enough to withstand the mechanical stress caused by the removal of the substrate 1. For example, glass, silicon substrate, A SUS substrate or the like can be used.

Next, as shown in FIG. 15, a part of the substrate 1 is removed from the back surface side of the substrate 1 (FIG. 3K). Grinding is mentioned as this method, and the thickness of the substrate 1 can be controlled with high accuracy. At this time, as shown in FIG. 13, the amount of grinding is set so as to be the amount finally required by the substrate 1. By doing so, the etching process of the upper electrode layer 5, the piezoelectric layer 4, the lower electrode layer 3, the buffer layer 2 and the substrate 1 which applies a load such as stress to the substrate 1 in the manufacturing process can be processed in a thick state of the substrate 1. Therefore, cracking of the substrate 1 can be reduced as much as possible.

This grinding needs to be carried out to some extent until the predetermined substrate thickness is reached even if the amount of grinding progresses and the groove 9 penetrates. 13 surface and at least the electronic device 1
Since it is fixed to the outer peripheral surface of the substrate 3, the individual electronic devices 13 are separated from each other as shown in FIG. 18 even if grinding is continued for a while to further adjust the thickness of the substrate 1. Will never fall apart.

Further, as described above, the outer periphery of the substrate 1 on the side where the grinding is advanced has a trapezoidal shape smaller than that on the opposite side, so that even if the grinding is further performed after the groove 9 penetrates, the side surface of the groove 9 and the grinding are performed. It is less likely that the corner portion of the surface (a portion in FIG. 15) will be damaged.

In the case where the substrate 1 having a trapezoidal shape has an adverse effect on the frequency characteristics of the angular velocity sensor and the like, the following process is performed. That is, FIG.
As shown in FIG. 3, when the substrate 1 is etched vertically downward, and when the etching progresses to a point just before the finally required thickness, the etching conditions are changed so that the etching is performed on the side wall of the substrate 1. It is performed so that it spreads (a portion in FIG. 19). As a result, even if grinding is advanced from the back surface side of the substrate 1 and the groove 9 penetrates, damage to the side surface of the groove 9 and the corner portion (a portion in FIG. 19) of the ground surface can be reduced, and most of the substrate 1 It can be a solid with a vertical surface.
As a result, there is an operational effect that it is difficult for inconveniences such as adversely affecting the frequency characteristics to occur. As a method of changing the etching conditions so that the etching spreads to the side wall of the substrate 1, there is a method of using xenon difluoride as an etching gas. It becomes possible to spread to the side wall side like.

Then, the dummy substrate 11 is removed (see FIG.
L), the resist mask 8 is removed as shown in FIG. 16 (FIG. 3M) by the same method as the method for removing the element forming resist film 7 to obtain the angular velocity sensor 15.
If necessary, as shown in FIG. 20, it is mounted on the mounted body, for example, the outer case 14 (FIG. 3N).

Although the angular velocity sensor is used as the electronic component in the above description, the electronic component is not limited to this.
For example, electronic parts such as a chip resistor, a vibrator, and an actuator also have similar effects.

[0053]

As described above, according to the present invention, the first step of forming a plurality of electronic elements on the surface of the substrate and the second step of forming the groove on the surface side of the substrate along the outer periphery of the electronic element. And a third step of separating the plurality of electronic elements from each other by removing a part of the substrate from the back side of the substrate until the groove is reached, and the back side of the substrate By removing a part of the substrate, a plurality of electronic elements formed on the substrate can be separated into individual pieces, so that there is an effect that efficient production can be achieved.

In addition, in the step of forming an electronic element on the substrate, the substrate has a sufficient thickness, and the substrate is made to have a desired thickness by removing a part of the substrate from the back side of the substrate later. Even with a small-sized electronic element having a small thickness, cracking defects can be reduced, and as a result, it is possible to contribute to improvement in productivity.

[Brief description of drawings]

FIG. 1 is a perspective view of an angular velocity sensor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a flowchart showing a manufacturing process of the angular velocity sensor according to the embodiment of the present invention.

FIG. 4 is a sectional view showing a part of the manufacturing process.

FIG. 5 is a sectional view of the same.

FIG. 6 is a sectional view of the same.

FIG. 7 is a sectional view of the same.

FIG. 8 is a sectional view of the same.

FIG. 9 is a sectional view of the same.

FIG. 10 is a sectional view of the same.

FIG. 11 is a sectional view of the same.

FIG. 12 is a sectional view of the same.

FIG. 13 is a sectional view of the same.

FIG. 14 is a sectional view of the same.

FIG. 15 is a sectional view of the same.

FIG. 16 is a sectional view of the same.

FIG. 17 is a perspective view showing a part of the manufacturing process.

FIG. 18 is a perspective view of the same.

FIG. 19 is a sectional view showing a part of the manufacturing process.

FIG. 20 is a perspective view after mounting the angular velocity sensor according to the embodiment of the present invention.

[Explanation of symbols]

1 substrate 2 buffer layers 3 Lower electrode layer 4 Piezoelectric layer 5 Upper electrode layer 5A excitation electrode 5B detection electrode 6 auxiliary electrodes 7 Element forming resist film 8 Resist mask 9 grooves 10A arm 10B arm 11 Dummy substrate 12 Adhesive layer 13 electronic devices 14 Outer case 15 Angular velocity sensor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michihiko Hayashi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 2F105 BB15 CC01 CD02 CD06

Claims (10)

[Claims] 1. A first step of forming a plurality of electronic elements on a front surface of a substrate, a second step of forming a groove on the front surface side of the substrate along an outer periphery of the electronic element, and a back surface side of the substrate. A method for manufacturing an electronic component, comprising a third step of separating a part of the substrate until reaching the groove to separate the plurality of electronic elements from each other. 2. The second step includes the step of forming a resist mask except for the surface of the substrate on which the groove is formed, the step of performing dry etching, and the step of removing the resist mask. A method for manufacturing the described electronic component. 3. The method of manufacturing an electronic component according to claim 2, wherein the step of removing the resist mask is performed after the third step. 4. The method of manufacturing an electronic component according to claim 2, wherein the dry etching is performed using at least two kinds of gases. 5. The method of manufacturing an electronic component according to claim 4, wherein at least one kind of gas used for dry etching is a gas that promotes etching, and at least another kind of gas is a gas that suppresses etching. 6. The etching is performed using a mixed gas of a gas that promotes etching and a gas that suppresses etching,
The method of manufacturing an electronic component according to claim 5, wherein the etching is performed by increasing the mixing ratio of the gas that promotes the etching as the groove is deeply dug from the surface of the substrate. 7. The etching is repeated by alternately switching between a gas that promotes etching and a gas that suppresses etching, and as the groove is deeply digged from the surface of the substrate, the time for switching the gas that promotes etching is increased to perform etching. The method for manufacturing an electronic component according to claim 5, which is performed. 8. The method of manufacturing an electronic component according to claim 2, wherein after the dry etching is performed, the dry etching is further performed using xenon difluoride as a gas. 9. A method of removing a part of a substrate in the third step, wherein a dummy substrate is used to connect at least the front surface of the electronic element and the dummy substrate via an adhesive layer, and grinding is performed from the rear surface side of the substrate. The method for manufacturing an electronic component according to claim 1, which is performed by. 10. The method of manufacturing an electronic component according to claim 9, wherein the adhesive layer is formed on the surface of the electronic element and at least on the outer peripheral surface of the electronic element.