CN112367060A

CN112367060A - Adhering method for metal-packaged EMI filter

Info

Publication number: CN112367060A
Application number: CN202011325295.1A
Authority: CN
Inventors: 卢鹏程; 孙江超; 张昊; 王远才; 冀兴军
Original assignee: Beijing Aerospace Micro Electronics Technology Co Ltd
Current assignee: Beijing Aerospace Micro Electronics Technology Co Ltd
Priority date: 2020-11-23
Filing date: 2020-11-23
Publication date: 2021-02-12

Abstract

The invention relates to a cementing method of a metal-encapsulated EMI filter, which comprises the following steps: s1: coating an adhesive at a set position of a product, and curing the adhesive at 120-130 ℃; s2: placing the pipe cap and the product subjected to the step S1 in an inert gas atmosphere, and heating to remove moisture; s3: sealing the product and the cap subjected to the step S2 under an inert gas atmosphere. The method of three procedures of high-temperature curing, air washing to remove moisture and nitrogen sealing of the tube realizes the high-reliability cementation of the metal-packaged EMI filter, can effectively improve the production quality and reduce the water vapor content in the product. The method has the characteristics of simplicity, easiness in operation, low production cost, high yield, wide application range and strong universality.

Description

Adhering method for metal-packaged EMI filter

Technical Field

The invention belongs to the field of filter packaging, and particularly relates to a cementing method of a metal-packaged EMI filter.

Background

In the process of developing aerospace electronic products, a large amount of adhesive is used as anti-vibration reinforcing materials for components, wires and the like, so that the construction is convenient and the operation is simple.

The detailed requirements on the cementation process are also explicitly provided in standards of QJ2829 Universal technical requirement for potting and cementation of aerospace electronic and electrical products, QJ3258 technical requirement for silicon rubber cementing and potting of aerospace electronic and electrical products and the like. Among them, the above-mentioned technical requirements are also required to be satisfied in the case of a metal-encapsulated EMI filter (electromagnetic interference filter). In order to ensure the water vapor content and the atmosphere environment in the sealed product, the requirement on the adhesive is high.

However, in the prior art, the through groove for metal packaging of the EMI filter applies an adhesive at normal temperature to directly seal the tube, and most of the adhesive, except for the expensive space-level low-outgassing adhesive, releases gas and water vapor during the curing process, which causes the water vapor content and atmosphere environment inside the packaged and sealed product, and further affects the reliability of the product.

Disclosure of Invention

In order to solve the technical problem, the invention provides a method for adhering a metal-encapsulated EMI filter.

The technical scheme for solving the technical problems is as follows: a method of adhesively bonding a metal-encapsulated EMI filter, comprising the steps of:

s1: coating an adhesive at a set position of a product, and curing the adhesive at 120-130 ℃;

s2: placing the pipe cap and the product subjected to the step S1 in an inert gas atmosphere, and heating to remove moisture;

s3: sealing the product and the cap subjected to the step S2 under an inert gas atmosphere.

The beneficial effect of this application is: the method of three procedures of high-temperature curing, air washing to remove moisture and nitrogen sealing of the tube realizes the high-reliability cementation of the metal-packaged EMI filter, can effectively improve the production quality and reduce the water vapor content in the product. The method has the characteristics of simplicity, easiness in operation, low production cost, high yield, wide application range and strong universality.

Further, the adhesive is silicon rubber. Silicone rubber is a common adhesive, and has low price and good adhesion.

Further, the curing time is greater than 24 hours. The curing time is set to be more than 24h, and the steam in the adhesive can be fully discharged.

Further, in step S2, the inert gas is nitrogen. The nitrogen has inactive chemical property and can react with hydrogen to generate ammonia gas under the conditions of high temperature, high pressure and catalyst, so that the moisture can be removed in the nitrogen atmosphere, and the adhesive can be prevented from reacting.

Further, in the step S2, the heating and dehumidifying temperature is 120 to 130 ℃, and the heating and dehumidifying time is more than 2 hours. The moisture is removed by the high-temperature gas washing of the inert gas, so that the water vapor content of the product before tube sealing is ensured.

Further, in step S3, the inert gas is nitrogen. The nitrogen has inactive chemical property and can react with hydrogen to generate ammonia gas under the conditions of high temperature, high pressure and catalyst, so that the tube is sealed under the nitrogen atmosphere, the reaction of an adhesive can be prevented, and components and parts are protected.

Further, in step S3, the product and the cap are sealed by an energy storage welding and tube sealing machine. The energy storage welding pipe sealing machine stores energy by using a capacitor, when the energy can melt a small-area welding point, the capacitor instantaneously discharges, and the welding time of the energy storage welding machine is generally 3 thousandth of a second.

Drawings

FIG. 1 is a left side view of an X-ray of a metal encapsulated EMI filter obtained by sealing tubes in example 2 of the present application;

FIG. 2 is a schematic process flow diagram of the present application;

Detailed Description

The principles and features of this application are described below in conjunction with the following drawings, the examples of which are set forth to illustrate the application and are not intended to limit the scope of the application.

In the description of the present specification, it is to be understood that the terms "center", "length", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "inner", "outer", "peripheral side", "circumferential", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present specification.

In the description of the present specification, "a plurality" means at least two, e.g., two, three, etc., unless explicitly defined otherwise.

In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

The terms used in the present specification are those general terms currently widely used in the art in consideration of functions related to the present disclosure, but they may be changed according to the intention of a person having ordinary skill in the art, precedent, or new technology in the art. Also, specific terms may be selected by the applicant, and in this case, their detailed meanings will be described in the detailed description of the present disclosure. Therefore, the terms used in the specification should not be construed as simple names but based on the meanings of the terms and the overall description of the present disclosure.

Flowcharts or text are used herein to illustrate the operational steps performed in accordance with embodiments of the present application. It should be understood that the operational steps in the embodiments of the present application are not necessarily performed in the exact order recited. Rather, the various steps may be processed in reverse order or simultaneously, as desired. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

The following discloses many different embodiments or examples for implementing the subject technology described. While specific examples of one or more arrangements of features are described below to simplify the disclosure, the examples should not be construed as limiting the present disclosure, and a first feature described later in the specification in conjunction with a second feature can include embodiments that are directly related, can also include embodiments that form additional features, and further can include embodiments in which one or more additional intervening features are used to indirectly connect or combine the first and second features to each other so that the first and second features may not be directly related.

Example 1

As shown in fig. 2, the present application discloses an embodiment of a method for attaching a metal-encapsulated EMI filter, comprising the steps of:

s1: based on a design drawing, coating an adhesive at a set position of a product, and curing the adhesive. Specifically, in the embodiment disclosed by the application, GD414 type silicon rubber is adopted as the adhesive, and the product is cured at a high temperature of 120 ℃ for 24 hours before the tube is sealed.

S2: and placing the tube cap and the product subjected to the step S1 in a nitrogen atmosphere, and heating to remove moisture. Specifically, the product and the cap to be used are put into an oven and dehumidified for 2h at 120 ℃ under the condition of nitrogen gas washing.

S3: the product and the cap subjected to the step S2 are subjected to tube sealing under a nitrogen gas atmosphere. Specifically, the product after dehumidification and the pipe cap pass through a glove box together, and are transferred into an energy storage welding pipe sealing machine in nitrogen atmosphere in a sealing environment for pipe sealing.

Example 2

s1: coating adhesive at a set position of a product, and curing the adhesive. Specifically, in the embodiment disclosed by the application, GD414 type silicon rubber is adopted as the adhesive, and the product is cured at a high temperature of 130 ℃ for 24 hours before the tube is sealed.

S2: and placing the tube cap and the product subjected to the step S1 in a nitrogen atmosphere, and heating to remove moisture. Specifically, the product and the cap to be used were put into an oven and dehumidified at 130 ℃ for 2 hours under a nitrogen gas purge.

The final product prepared in this application is shown in figure 1.

Example 3

s1: coating adhesive at a set position of a product, and curing the adhesive. Specifically, in the embodiment disclosed by the application, GD414 type silicon rubber is adopted as the adhesive, and the product is cured at a high temperature of 125 ℃ for 24 hours before the tube is sealed.

S2: and placing the tube cap and the product subjected to the step S1 in a nitrogen atmosphere, and heating to remove moisture. Specifically, the product and the cap to be used were put into an oven and dehumidified at 125 ℃ for 2 hours under a nitrogen gas purge.

The results of the tests performed in the above examples 1 to 3 all meet the corresponding requirements of QJ2829 and QJ 3258.

As can be seen from figure 1, the product after the pipe sealing of the invention has no bubble generation and good sealing property.

According to the method, before tube sealing, the adhesive is cured at high temperature at 120-130 ℃, so that most compounds generated by a colloid reaction can be released while the curing reaction of the adhesive is accelerated.

The method and the device have the advantages that the step of adding moisture removal under the inert atmosphere is added, and the water vapor content and the atmosphere environment before the product is sealed are guaranteed through inert gas washing.

This application is through sealing the pipe under inert gas atmosphere, and the reaction between other gases can effectual suppression in the inert gas environment, inside solder joint of protection product and components and parts.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of adhesively bonding a metal-encapsulated EMI filter, comprising the steps of:

2. A method of affixing a metal-encapsulated EMI filter according to claim 1, wherein said adhesive is silicone rubber.

3. A method of securing a metal-encapsulated EMI filter as recited in claim 2, wherein said curing time is greater than 24 hours.

4. A method of attaching a metal-encapsulated EMI filter as set forth in any one of claims 1 to 3, wherein in said step S2, said inert gas is nitrogen.

5. A method for adhering a metal-encapsulated EMI filter according to claim 4, wherein in the step S2, the temperature for removing moisture by heating is 120 to 130 ℃, and the time for removing moisture by heating is more than 2 hours.

6. A method of attaching a metal-encapsulated EMI filter as set forth in any one of claims 1 to 3, wherein in said step S3, said inert gas is nitrogen.

7. A method of attaching a metal-encapsulated EMI filter as set forth in claim 6, wherein said product and said cap are sealed by an energy storage tube sealing machine in said step S3.