TW202043163A - Method for protecting quartz wafer electrode - Google Patents

Abstract

The invention discloses a method for protecting a quartz wafer electrode, which comprises the following steps: S1, cleaning a quartz wafer, and then dehydrating and drying the quartz wafer; S2, depositing upper bonding metal layers on the upper surface and the lower surface of the quartz wafer; S3, uniformly depositing an upper metal electrode layer on the bonding metal layer; and S4, depositing protective layers which completely cover the metal electrode layers on the upper surface and the lower surface of the quartz wafer. According to the method, the protective layer is deposited on the quartz wafer, and the quartz wafer is removed through the alkaline solution or other corrosive liquid when used later, so that the quality of the metal electrode layer can be protected during storage and transportation of the quartz wafer, and oxidation, abrasion and other undesirable conditions of the metal electrode layer are prevented. When the quartz wafer is used later, the quartz wafer can be removed by an alkaline solution, so that the quality of a metal electrode on the quartz wafer is not damaged, and the assembly operation of the quartz crystal oscillator can be smoothly carried out.

Description

A method for protecting quartz wafer electrodes

The invention relates to the field of electronic technology, in particular to a method for protecting quartz wafer electrodes.

As a device that generates stable oscillation signals, quartz crystal oscillators are widely used in communications, radar, precision calculations, precision balances, mobile phones, aviation, electronic watches, automobiles and other fields. The quartz crystal oscillator is composed of a quartz wafer with electrodes and a package shell with leads. Its structure is shown in Figure 1.

At present, the electrode materials of quartz wafers generally use metal materials such as gold, silver, and aluminum. Before depositing these metal electrode materials, one or more bonding metal layers are generally deposited. The bonding metal layers include manganese, nickel, chromium, titanium, and tungsten. And other materials. However, among the electrode materials, in addition to gold metal, other metal electrode materials are prone to chemical reactions with substances in the air under normal atmospheric conditions. When these chemically reacted metals are used as the electrodes of the quartz wafer, the electrical properties of the quartz wafer will deteriorate, resulting in the final device not working properly. In addition, the quartz wafer with the metal electrode layer directly exposed will collide during transportation and damage the metal electrode layer. At the same time, the thickness of the metal electrode layer is extremely small, usually several hundred nanometers, and direct collisions can easily cause the metal electrode layer to be scratched. Therefore, how to prevent the metal electrode material on the quartz wafer from being damaged by collisions during transportation and the chemical reaction not to occur during the storage and transportation of the quartz wafer has become very important.

In view of this, our inventors devoted themselves to further research, and proceeded to develop and improve, in the hope of a better design to solve the above problems, and after continuous experimentation and modification, the present invention came out.

The purpose of the present invention is to provide a method for protecting quartz wafer electrodes, which solves the problem of how to prevent the metal electrode material on the quartz wafer from being damaged by collision and the technology that does not cause chemical reaction during the storage and transportation of the quartz wafer problem.

The technical scheme adopted by the present invention is as follows:

A method for protecting quartz wafer electrodes includes the following steps:

S1. Wash the quartz wafer, and then dehydrate and dry;

S2, deposit one or several bonding metal layers on the upper and lower surfaces of the quartz wafer;

S3, depositing a layer or base metal electrode layer on the bonding metal layer obtained in step S2;

S4. Depositing a protective layer that completely covers the metal electrode layer on both the upper and lower surfaces of the quartz wafer;

S5. Before encapsulating the quartz wafer into a quartz crystal oscillator device, the protective layer is removed by physical or chemical means, the quartz wafer is cleaned and dried, and finally, the quartz wafer with electrode patterns is encapsulated into a quartz crystal oscillator device.

The metal material of the metal electrode layer has poor adhesion to quartz. Therefore, on the basis of ensuring the use of metal with high electrical properties as the metal electrode layer, it is necessary to provide an intermediate transition layer between the metal electrode layer with such high electrical properties and the quartz. That is, the metal bonding layer. The adhesion between the metal bonding layer and the quartz is good. By setting the metal bonding layer to support the metal electrode layer, it can not only improve the stability of the metal electrode layer, prevent the metal electrode layer from falling off, but also ensure high electrical performance.

After the metal electrode layer is covered with a protective layer, it isolates the water, oxygen, nitrogen, dust and other substances in the air from chemical reaction with the metal electrode, and avoids the situation that it causes the electrical performance of the metal electrode to fail. Then, the quartz wafer with the protective layer is stored or transported to a specific place. In this process, although the quartz wafer will shake or collide, due to the setting of the protective layer, the metal electrode layer will not be scratched or hit in the collision, maintaining the inherent properties of the metal electrode and ensuring the metal electrode layer High quality and integrity of quartz wafers.

When quartz wafers need to be used, physical or chemical methods are used to remove the protective layer of different materials. Preferably, the protective layer is removed by an alkaline solution. The alkaline solution includes sodium hydroxide, potassium hydroxide or Sodium carbonate. After removing the protective layer, the quartz wafer is cleaned and dried. Finally, the quartz wafer with electrode patterns is packaged into a quartz crystal oscillator device. Although the cleaning and drying process after removing the protective layer before packaging will also degrade the electrical performance of the electrode, due to the short exposure time of the electrode during this process, this part of the electrical performance degradation can be ignored.

In the present invention, by depositing a protective layer on the quartz wafer, and removing it by alkaline solution or other etching solutions when the quartz wafer is used later, this can not only protect the quality of the metal electrode layer when the quartz wafer is stored and transported, but also Prevent the metal electrode layer from oxidation and abrasion; it can also be removed by alkaline solution when the quartz wafer is used in the later stage, which will not damage the quality of the metal electrode on the quartz wafer, but also can smoothly assemble the quartz crystal oscillator .

Due to the adoption of this technical solution, the beneficial effects of the present invention are:

1. The present invention is a method for protecting quartz wafer electrodes. The adhesion between the metal material of the metal electrode layer and the quartz is poor. Therefore, on the basis of ensuring that the metal with high electrical performance is used as the metal electrode layer, it is necessary to An intermediate transition layer is set between the metal electrode layer and the quartz, that is, the metal bonding layer; the adhesion between the metal bonding layer and the quartz is better, and the metal bonding layer is provided to support the metal electrode layer, which not only improves the stability of the metal electrode layer, but also prevents The metal electrode layer falls off, which can ensure high electrical performance;

2. The present invention is a method for protecting quartz wafer electrodes. After the metal electrode layer is covered with a protective layer, it isolates the water, oxygen, nitrogen, dust and other substances in the air from chemical reaction with the metal electrode, thereby avoiding the electrical properties of the metal electrode. Failure occurs. Then, the quartz wafer with the protective layer is stored or transported to a specific place. In this process, although the quartz wafer will shake or collide, due to the setting of the protective layer, the metal electrode layer will not be scratched or hit in the collision, maintaining the inherent properties of the metal electrode and ensuring the metal electrode layer High quality and integrity of quartz wafers;

3. A method of protecting quartz wafer electrodes of the present invention. When quartz wafers are used later, they are removed by alkaline solution or other etching solutions. This does not damage the quality of the metal electrodes on the quartz wafers, and can smoothly perform the quartz crystal oscillation Assembly operations.

Regarding the technical means of our inventors, several preferred embodiments are described in detail below in conjunction with the drawings, so as to provide a thorough understanding and approval of the present invention.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and not to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and illustrated in the drawings herein may be arranged and designed in various different configurations.

Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person with ordinary knowledge in the technical field of the present invention without making progressive work shall fall within the protection scope of the present invention.

All the features disclosed in this specification, or all disclosed methods or steps in the process, except for mutually exclusive features and/or steps, can be combined in any manner.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 to 5.

Example 1

A method for protecting quartz wafer electrodes includes the following steps:

S1. Wash the quartz wafer, and then dehydrate and dry;

S2, deposit a bonding metal layer on the upper and lower surfaces of the quartz wafer;

S3, depositing a metal electrode layer on the bonding metal layer obtained in step S2;

S4. Depositing a protective layer that completely covers the metal electrode layer on both the upper and lower surfaces of the quartz wafer;

S5. Before encapsulating the quartz wafer into a quartz crystal oscillator device, the protective layer is removed by physical or chemical means, the quartz wafer is cleaned and dried, and finally, the quartz wafer with electrode patterns is encapsulated into a quartz crystal oscillator device.

The metal material of the metal electrode layer has poor adhesion to quartz. Therefore, on the basis of ensuring the use of metal with high electrical properties as the metal electrode layer, it is necessary to provide an intermediate transition layer between the metal electrode layer with such high electrical properties and the quartz. That is, the metal bonding layer, as shown in Figure 2. The adhesion between the metal bonding layer and the quartz is good. By setting the metal bonding layer to support the metal electrode layer, it can not only improve the stability of the metal electrode layer, prevent the metal electrode layer from falling off, but also ensure high electrical performance.

After the metal electrode layer is covered with a protective layer, it isolates the water, oxygen, nitrogen, dust and other substances in the air from chemical reaction with the metal electrode, and avoids the situation that it causes the electrical performance of the metal electrode to fail. Then, the quartz wafer with the protective layer is stored or transported to a specific place. In this process, although the quartz wafer will shake or collide, due to the setting of the protective layer, the metal electrode layer will not be scratched or hit in the collision, maintaining the inherent properties of the metal electrode and ensuring the metal electrode layer High quality and integrity of quartz wafers.

When quartz wafers need to be used, physical or chemical methods are used to remove them according to the protective layer of different materials. After removing the protective layer, the quartz wafer is cleaned and dried. Finally, the quartz wafer with electrode patterns is packaged into a quartz crystal oscillator device. Although the cleaning and drying process after removing the protective layer before packaging will also degrade the electrical performance of the electrode, due to the short exposure time of the electrode during this process, this part of the electrical performance degradation can be ignored.

The removal of the protective layer is preferably removed by an alkaline solution. When it is removed by a chemical method, at this time, the selection of the protective layer requires a large reaction rate between the protective layer and the alkaline solution, and the alkaline solution The reaction speed with the bonding metal layer, the electrode layer and the wafer is very slow, far less than the reaction rate of the alkaline solution and the protective layer. Based on the above requirements, the alkaline solution can be sodium hydroxide, potassium hydroxide or sodium carbonate. The protective layer material is a material with a specific functional group.

When the protective layer is physically removed, the selection of the protective layer is not limited to the chemical properties between the protective layer, the bonding metal layer, the electrode layer, and the wafer.

In the present invention, by depositing a protective layer on the quartz wafer, and removing it by alkaline solution or other etching solutions when the quartz wafer is used later, this can not only protect the quality of the metal electrode layer when the quartz wafer is stored and transported, but also Prevent the metal electrode layer from oxidation and abrasion; it can also be removed by alkaline solution when the quartz wafer is used in the later stage, which will not damage the quality of the metal electrode on the quartz wafer, but also can smoothly assemble the quartz crystal oscillator .

Example 2

This embodiment is a specific implementation description of the material of the protective layer.

In the present invention, the material of the protective layer is a polymer material.

Preferably, the material of the protective layer is one or more of the following materials: plastic, rubber, fiber, paint, adhesive, polymer-based composite material, and the material of the protective layer includes but is not limited to the above-mentioned materials.

Preferably, the protective layer is a film, specifically a photosensitive adhesive.

Further, the S4 adopts one of the following processes to deposit a protective layer on the surface of the metal electrode: photolithography, printing, coating, chemical synthesis, and physical bonding.

When photosensitive glue is used, after step S4, step S5 is set to expose the photosensitive glue and irradiate with ultraviolet light to speed up the fixing of the protective layer, so as to quickly carry out subsequent inventory or transportation operations of the quartz wafer.

The photosensitive glue is irradiated by light, and the corresponding chemical reaction principle is shown in Figure 3.

When the photosensitive glue is removed, the corresponding chemical reaction principle is shown in Figure 4 and Figure 5. The photosensitive glue first reacts with water, and the product reacts with alkali to dissolve it in the lye and remove the photosensitive adhesive deposited on the wafer. Glue removal.

Example 3

This embodiment is an implementation description of the material of the bonding metal layer.

In the present invention, the material of the bonding metal layer is one or more of the following materials: manganese, nickel, chromium, titanium, and tungsten. The material of the bonding metal layer includes but is not limited to the above-mentioned materials.

Example 4

This embodiment is an implementation description of the material of the metal electrode layer.

In the present invention, the material of the metal electrode layer is one or more of the following materials: gold, silver, and aluminum. The material of the metal electrode layer includes but is not limited to the above-mentioned materials.

Example 5

This embodiment is an implementation description of the material of the metal electrode layer.

In the present invention, n layers of bonding metal layers are deposited on both the upper and lower surfaces of the quartz wafer, where n≥1.

Further, x layers of electrode metal layers are deposited on the upper and lower surfaces of the quartz wafer, where x≧1.

Example 6

This embodiment illustrates the specific implementation of the overall technical solution of the present invention.

The protection steps of the present invention for 24MHz, AT-cut 3225 quartz wafer are as follows:

S1. Clean the 24MHz, AT-cut 3225 quartz wafer, and then dehydrate and dry it;

S2, deposit a layer of 100 nanometer thick chromium film with a specific pattern on both the upper surface and the lower surface of the quartz wafer, and the specific pattern is consistent with the electrode pattern to be deposited on the wafer;

S3. Deposit a silver electrode with the required electrode pattern with a thickness of 500 nm on the chromium film, and deposit the silver film with the same thickness on both sides of the quartz wafer;

S4. Make a layer of photosensitive glue on the surface of the metal electrode by photolithography, and the photosensitive glue just completely covers the metal pattern.

S5. Transport the wafer with photosensitive adhesive to the packaging factory;

S6. After the packaging factory removes the photosensitive glue, immediately encapsulate the quartz wafer with metal electrodes; after the packaging is completed, a quartz crystal oscillator device is formed.

S7. Perform sealing test, electrical performance test, aging test, etc. on the quartz crystal oscillator device, and then select qualified products for packaging and shipping.

The above are only the preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field of the present invention with ordinary knowledge may not make progress within the technical scope disclosed by the present invention. Any changes or replacements thought of by sex work shall be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the patent application.

In summary, the technical means disclosed in the present invention can effectively solve the conventional problems and achieve the expected purpose and effect. It has not been seen in the publications, has not been used publicly, and has long-term progress before the application. The patent law claims that the invention is correct. Yan filed an application in accordance with the law and prayed that Jun Shanghui would give a detailed examination and grant a patent for invention.

However, the above are only a few preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the description of the invention are all It should still fall within the scope of the invention patent.

〔this invention〕 1: Quartz wafer 2: Encapsulation shell 3: Insulator 4: crystal seat 5: Wiring 6: Bonding metal layer 7: Metal electrode layer

Figure 1 is a schematic diagram of the principle structure of a quartz crystal oscillator. Fig. 2 is a cross-sectional view of the quartz wafer of the present invention. Figure 3 is a schematic diagram of the chemical reaction when the photosensitive adhesive is exposed to light. 4 and 5 are schematic diagrams of the chemical reaction between the photosensitive adhesive obtained after curing and the alkaline solution.

1: Quartz wafer

6: Bonding metal layer

7: Metal electrode layer

Claims (10)

A method for protecting quartz wafer electrodes, which is characterized in that it comprises the following steps: S1. Wash the quartz wafer, and then dehydrate and dry; S2, deposit a bonding metal layer on the upper and lower surfaces of the quartz wafer; S3, depositing a metal electrode layer on the bonding metal layer obtained in step S2; S4. Depositing a protective layer that completely covers the metal electrode layer on both the upper and lower surfaces of the quartz wafer; S5. Before the quartz wafer is packaged into a quartz crystal oscillator device, the protective layer is removed by physical or chemical means, the quartz wafer is cleaned and dried, and finally the quartz wafer is packaged into a quartz crystal oscillator device. A method for protecting quartz wafer electrodes as described in item 1 of the scope of patent application, wherein when the protective layer is removed by the chemical method, an alkaline solution is used to remove the protective layer at room temperature, and a reaction between the alkaline solution and the protective layer is required The rate is large, but the reaction rate of the alkaline solution with the bonding metal layer, the electrode layer and the wafer is very slow, far less than the reaction rate of the alkaline solution and the protective layer. As described in the first item of the scope of patent application, a method for protecting a quartz wafer electrode, wherein the material of the protective layer is one or more of the following materials: plastic, rubber, fiber, paint, adhesive, polymer base Composite materials. The method for protecting quartz wafer electrodes as described in item 3 of the scope of patent application, wherein the protective layer is a thin film. As described in the third item of the scope of patent application, a method for protecting quartz wafer electrodes, wherein the step S4 adopts any one of the following processes to deposit a protective layer on the surface of the metal electrode: photolithography, printing, coating, chemical synthesis , Physical bonding. The method for protecting quartz wafer electrodes as described in any one of items 1 to 5 in the scope of the patent application, wherein the material of the bonding metal layer is one or more of the following materials: manganese, nickel, chromium, titanium, Tungsten. The method for protecting quartz wafer electrodes as described in any one of items 1 to 5 of the scope of patent application, wherein the material of the metal electrode layer is one or more of the following materials: gold, silver, and aluminum. As described in any one of items 1 to 5 of the scope of patent application, a method for protecting a quartz wafer electrode, wherein n layers of bonding metal are deposited on both the upper and lower surfaces of the quartz wafer, and the n≥1. A method for protecting quartz wafer electrodes as described in any one of items 1 to 5 of the scope of patent application, wherein x layers of electrode metal layers are deposited on both the upper and lower surfaces of the quartz wafer, and the x≥1. The method for protecting quartz wafer electrodes as described in item 2 of the scope of patent application, wherein the alkaline solution includes sodium hydroxide, potassium hydroxide or sodium carbonate.

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