A sealing method for an ultra-thick high-low frequency metal shell

Abstract

The application discloses a sealing method of an ultra-thick high-low frequency metal shell, which comprises the following steps: pre-oxidation and pre-plating of raw materials, cleaning of a mold; pre-oxidation and pre-plating of the raw materials to obtain a shell, a lead wire and glass; a section of glass is assembled with the shell and the lead wire, a graphite column is sleeved on the lead wire to press the glass, and the whole is placed in a selected atmosphere to perform first sealing at 800-1200 DEG C. After the first sealing, the mold and the graphite column are removed, the sealed metal shell is treated in diluted hydrofluoric acid for dozens of seconds, a second section of glass is assembled, and the assembled shell is placed at 800-1200 DEG C to perform second sealing. The plating mode of the high-low frequency metal shell is gold plating, copper plating, nickel plating or the like. The application uses step-by-step sealing to replace conventional one-step sealing, and meets the use requirements of high insulation and voltage resistance of the metal shell; and provides technical support for mass production of other types of ultra-thick metal shells.

Description

Technical Field

[0001] This invention relates to the field of glass sealing and electronic packaging technology, and more specifically to a sealing method for an ultra-thick high- and low-frequency metal casing. Background Technology

[0002] With the rapid development of communication technology, electronic devices and systems are becoming increasingly integrated. This has led to higher demands on metal housings, including miniaturization, integration, and modularity. Hybrid glass-sealed metal housings and high-low frequency hybrid connectors are now widely used in various fields.

[0003] During the sealing process, sealing metal casings with a standard sealing thickness (1-2.5mm) is relatively easy. However, once the sealing thickness exceeds 4mm, the sealing difficulty increases significantly. Typically, multiple glass preforms are used in combination, or glass tubes are used for sealing. However, sealing multiple glass preforms in combination can easily lead to severe glass overflow, while glass tubes often fail to meet the required weight and height. This frequently results in situations where the height is appropriate but the weight is insufficient, causing the glass to sink after sealing. Conversely, when the required weight is met, assembly and sealing may be impossible due to the height exceeding the acceptable range.

[0004] Therefore, it is necessary to develop a sealing method for ultra-thick high and low frequency metal shells to solve the above-mentioned technical problems. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a sealing method for ultra-thick high and low frequency metal shells, laying the foundation for the production and manufacturing of ultra-thick high and low frequency metal shells and other metal shells.

[0006] The technical solution adopted by this invention to solve the technical problem is: a sealing method for an ultra-thick high- and low-frequency metal shell, wherein the sealing method involves assembling the shell, leads, and glass and then placing them in a selected atmosphere; specifically, it includes the following steps:

[0007] Step 1) Pre-oxidize and inspect the raw materials to obtain the shell, leads and glass to be assembled;

[0008] Step 2) First, assemble a section of glass with the shell and lead wire. Then, put the graphite column on the lead wire and apply pressure to the glass. After assembly, place the whole assembly in the selected atmosphere and perform the first sealing at 800-1200℃.

[0009] Step 3) After the first sealing is completed, remove the mold and graphite column, and treat the sealed high and low frequency metal shells in diluted hydrofluoric acid for several tens of seconds.

[0010] Step 4) Assemble the second glass section onto the high and low frequency metal shell after the treatment in Step 3). After assembly, place it in the selected atmosphere and perform a second sealing at 800-1200℃.

[0011] Step 5) Plate the sealed high and low frequency metal shells.

[0012] Furthermore, the shell is made of 4J29 Kovar alloy, 4J33 Kovar alloy, carbon steel, stainless steel, or titanium.

[0013] Furthermore, the lead wire is made of 4J29 Kovar alloy, 4J29 copper core composite, 4J50 alloy, or 4J50 copper core composite.

[0014] Furthermore, the glass is BH glass, ELAN glass, or CORN glass.

[0015] Furthermore, in steps 2) and 4), the selected atmosphere gas is any one or a combination of two or more of nitrogen, helium, hydrogen, and oxygen.

[0016] Furthermore, in step 2), the first sealing time is 10-40 minutes; in step 4), the second sealing time is 10-40 minutes.

[0017] Furthermore, in step 5), the plating method of the high- and low-frequency metal shell is any one or a combination of two or more of gold plating, nickel plating, and copper plating.

[0018] The beneficial effects of this invention are as follows: Compared with the prior art, the sealing method for an ultra-thick high- and low-frequency metal shell provided by this invention has the following advantages:

[0019] 1) The sealing method for ultra-thick high and low frequency metal shells provided by this invention uses two glass sections for step-by-step sealing instead of the conventional one-step sealing of two glass sections. The process is simple, with good appearance and performance, and low defect rate. During step-by-step sealing, the resistance test after one-step sealing shows continuity, and there is a cavity between the two glass sections after sample cutting. This is because the organic polymers in the glass blank become gaseous and volatilize at high temperature. When sealing one glass section, the gas will escape through the top and bottom of the glass at the same time, thus ensuring that the gas is fully discharged. After the sealing of one glass section is completed, the sealing of the second glass section is carried out, which can avoid the formation of such cavities, thereby ensuring high insulation resistance and breakdown voltage, and effectively improving the quality of high and low frequency metal shells.

[0020] In existing two-section glass sealing processes, gas escape is obstructed at the junction of the two glass sections, preventing complete gas discharge and creating a cavity. This gas may be CH4. x CO y (x and y are, but are not limited to, integers). Because these possible gases have different electrical conductivity, they exhibit different phenomena (resistance decrease or conduction, withstand voltage breakdown).

[0021] 2) The sealing method for ultra-thick high and low frequency metal shells provided by this invention can provide technical support for the production and preparation of other ultra-thick metal shells. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the sealing method provided in the embodiment.

[0023] Figure 2 The image shows a cross-section of a metal casing obtained by the sealing method provided in the embodiment.

[0024] Figure 3 A structural schematic diagram of the sealing method provided for comparison.

[0025] Figure 4 The image shows a cross-section of a metal casing obtained by the sealing method provided for comparison.

[0026] Among them, 1-lead wire; 2-graphite column; 3-shell; 4-glass. Detailed Implementation

[0027] The present invention will be further illustrated below with specific embodiments. However, these examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] Example

[0029] like Figure 1 As shown, a sealing method for an ultra-thick high- and low-frequency metal casing is described. The sealing method involves assembling the casing, leads, and glass, and then placing them in a selected atmosphere. Specifically, it includes the following steps:

[0030] Step 1) Pre-oxidize and inspect the raw materials to obtain the shell, leads and glass to be assembled;

[0031] Step 2) First, assemble a section of glass with the shell and lead wire. Then, put the graphite column on the lead wire and apply pressure to the glass. After assembly, place the whole assembly in the selected atmosphere and perform the first sealing at 800-1200℃.

[0032] Step 3) After the first sealing is completed, remove the mold and graphite column, and treat the sealed high and low frequency metal shells in diluted hydrofluoric acid for several tens of seconds; this is to remove the graphite that adhered to the glass surface during the first sealing process, so as to prevent it from melting into the glass during the second sealing, which would cause a decrease in resistance or conduction.

[0033] Step 4) Assemble the second glass section onto the high and low frequency metal shell after the treatment in Step 3). After assembly, place it in the selected atmosphere and perform a second sealing at 800-1200℃.

[0034] Step 5) Plate the sealed high and low frequency metal shells.

[0035] The housing is made of 4J29 Kovar alloy, 4J33 Kovar alloy, carbon steel, stainless steel, or titanium. The lead wires are made of 4J29 Kovar alloy, 4J29 copper core composite, 4J50 alloy, or 4J50 copper core composite. The glass is BH glass, ELAN glass, or CORN glass.

[0036] In steps 2) and 4), the selected atmosphere gas is any one or a combination of two or more of nitrogen, helium, hydrogen, and oxygen.

[0037] In step 2), the first sealing time is 10-40 minutes; in step 4), the second sealing time is 10-40 minutes.

[0038] In step 5), the plating method of the high- and low-frequency metal shell is any one or a combination of two or more of gold plating, nickel plating, and copper plating.

[0039] The high- and low-frequency metal casings obtained by the above method have good appearance, and there are no voids between the glass sections after cross-section (e.g.) Figure 2 As shown), the resistance and withstand voltage tests both meet the requirements (DC500V 1GΩ, AC 1000V leakage current not exceeding 1mA).

[0040] Comparative Example

[0041] A sealing method for an ultra-thick high- and low-frequency metal casing includes: assembling the casing, leads, and glass, and then sealing them in a selected atmosphere; pre-oxidizing and inspecting the raw materials to obtain the casing, leads, and glass to be assembled; wherein the casing material is 4J29 Kovar alloy, 4J33 Kovar alloy, carbon steel, stainless steel, or titanium; the lead material is 4J29 Kovar alloy, 4J29 copper core composite, 4J50 alloy, or 4J50 copper core composite; and the glass is BH glass, ELAN glass, or CORN glass; the sealing temperature is 800–1200℃, and the time is 10–40 min; the plating method of the high- and low-frequency metal casing is any one or a combination of two or more of gold plating, copper plating, and nickel plating.

[0042] The sealing method is a one-step sealing of two glass sections; the one-step sealing is as follows: Figure 3 As shown, after assembling the two glass sections with the housing and leads simultaneously, they are placed in a selected atmosphere and sealed at 800–1200°C. The selected atmosphere is any one or a combination of two or more of nitrogen, helium, hydrogen, and oxygen.

[0043] The high- and low-frequency metal casings obtained by the method have good appearances, but after sectioning, gaps appear between the glass layers, as shown in the image. Figure 4The hole shown in the figure exhibits conductivity after resistance testing (DC500V 1GΩ) and breakdown after withstand voltage testing (AC 1000V leakage current not exceeding 1mA).

[0044] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims.

Claims

1. A sealing method for an ultra-thick high- and low-frequency metal casing, characterized in that, The sealing method involves assembling the housing, leads, and glass, and then placing them in a selected atmosphere; specifically, it includes the following steps: Step 1) Pre-oxidize and inspect the raw materials to obtain the shell, lead wires and glass to be assembled; Step 2) First, assemble a section of glass with the shell and lead wire. Then, put the graphite column on the lead wire and apply pressure to the glass. After assembly, place the whole assembly in the selected atmosphere and perform the first sealing at 800~1200 °C. Step 3) After the first sealing is completed, remove the mold and graphite column, and treat the sealed high and low frequency metal shells in diluted hydrofluoric acid for several tens of seconds. Step 4) Assemble the second glass section onto the high and low frequency metal shell after step 3), and place it in the selected atmosphere for a second sealing at 800~1200 °C. Step 5) Plate the sealed high and low frequency metal shells.

2. The sealing method for an ultra-thick high- and low-frequency metal casing as described in claim 1, characterized in that: The shell is made of 4J29 Kovar alloy, 4J33 Kovar alloy, carbon steel, stainless steel, or titanium.

3. The sealing method for an ultra-thick high- and low-frequency metal casing as described in claim 1, characterized in that: The lead wire is made of 4J29 Kovar alloy, 4J29 copper core composite, 4J50 alloy, or 4J50 copper core composite.

4. The sealing method for an ultra-thick high- and low-frequency metal casing as described in claim 1, characterized in that: In steps 2) and 4), the selected atmosphere gas is any one or a combination of two or more of nitrogen, helium, hydrogen, and oxygen.

5. The sealing method for an ultra-thick high- and low-frequency metal casing as described in claim 1, characterized in that: In step 2), the first sealing time is 10 to 40 minutes; in step 4), the second sealing time is 10 to 40 minutes.

6. The sealing method for an ultra-thick high- and low-frequency metal casing as described in claim 1, characterized in that: In step 5), the plating method of the high- and low-frequency metal shell is any one or a combination of two or more of gold plating, nickel plating, and copper plating.

Images