Glass cover-ceramic tube shell airtight packaging structure

Abstract

The utility model provides a glass cover-ceramic tube shell airtight packaging structure, and relates to the technical field of packaging structures. Comprising a ceramic tube shell with a cavity and a glass cover suitable for covering an opening of the cavity. Wherein the bottom of the glass cover is connected with the upper end part of the ceramic tube shell through a conductive silver adhesive, and the edge of the glass cover is hermetically connected with the ceramic tube shell through an organic silicon epoxy composite adhesive. According to the scheme, the sealing requirement can be better met.

Description

Technical Field

[0001] This utility model relates to the field of packaging structure technology, and more specifically, to a glass cover-ceramic tube shell hermetically sealed package. Background Technology

[0002] Metal-ceramic hermetic surface-mount devices (Surface Mount Devices) replace the plastic-packaged Zener diodes of the same type, improving the quality level of surface-mount products and meeting the requirements of military and high-reliability products. They offer advantages such as high versatility, high reliability, and direct replacement of plastic-packaged devices on printed circuit boards. However, existing hermetic metal-ceramic encapsulation requires high-temperature soldering, which has limitations and is not suitable for encapsulating non-metallic caps with ceramic components. Furthermore, current chip-to-base bonding uses eutectic bonding, while most chip-to-base bonding uses conductive or non-conductive adhesives, making this encapsulation method not universally applicable. Existing non-metallic caps and ceramic housings are generally sealed with non-conductive epoxy resin. However, during high-temperature curing, the increased pressure within the ceramic housing cavity can cause pores or cracks in the epoxy resin, leading to leakage and compromising hermeticity. This also fails to guarantee hermeticity after reflow soldering at approximately 250°C. Moreover, the non-conductive epoxy resin is prone to flow during curing, potentially seeping into the ceramic housing and causing defects. Utility Model Content

[0003] This utility model discloses a glass cap-ceramic tube shell hermetically sealed structure, which aims to improve the problems mentioned above.

[0004] The present invention adopts the following solution:

[0005] A glass cap-ceramic shell hermetic encapsulation structure includes: a ceramic shell with a cavity and a glass cap suitable for covering the opening of the cavity; wherein the bottom of the glass cap is connected to the upper end of the ceramic shell by conductive silver paste, and the edge of the glass cap is sealed to the ceramic shell by an organosilicon epoxy composite adhesive.

[0006] Furthermore, the ceramic tube shell is provided with a multi-layer ceramic structure, and the surface at the top that connects with the glass cover is provided with a gold-plated layer. The surface of the glass cover is provided with a gold-plated layer that matches the ceramic tube shell to increase the bonding strength of the connection.

[0007] Furthermore, an IC is attached to the bottom of the ceramic tube cavity and connected to an electrode via a gold wire; a light-emitting IC is disposed in the central area of ​​the glass cover surface, opposite to the IC, and the light-emitting IC is connected to an electrode via a gold wire.

[0008] Furthermore, the center of the IC reflective region coincides with the center of the light-emitting IC.

[0009] Furthermore, the IC and the light-emitting IC are disposed on the gold-plated layer.

[0010] Beneficial effects:

[0011] This application achieves a seal between the glass cover edge and the ceramic tube shell using a silicone-epoxy composite sealant. This ensures the airtightness between the ceramic tube shell cavity and the glass cover meets requirements and also solves the problem of flow. The silicone-epoxy composite sealant has a surface drying time of 10 minutes at room temperature and can be fully cured after 24 hours at room temperature, requiring no heating and reducing process costs. The silicone-epoxy composite sealant has a surface hardness of 35~45 degrees (Shore hardness), which is relatively soft and can, to some extent, offset or buffer the pressure generated by the increased temperature of the ceramic tube shell cavity during reflow soldering, thus maximizing its airtightness. At the same time, the silicone-epoxy composite sealant has an applicable temperature range of -60℃ to 250℃, which can meet most application scenarios. Attached Figure Description

[0012] Figure 1 This is a cross-sectional structural schematic diagram of a glass cover-ceramic tube shell airtight packaging structure according to an embodiment of the present invention;

[0013] Figure 2 This is a cross-sectional structural diagram of a ceramic tube shell with a glass cover-ceramic tube shell airtight sealing structure according to an embodiment of the present invention.

[0014] Figure 3 This is a schematic diagram of the internal structure of a ceramic tube shell in an embodiment of the present invention, which is a glass cover-ceramic tube shell airtight packaging structure.

[0015] Icons: 1. Glass cover; 2. Ceramic tube shell; 3. IC; 4. Light-emitting IC; 5. Conductive silver paste; 6. Organosilicon epoxy composite adhesive; 7. Gold plating layer; 8. Electrode. Detailed Implementation

[0016] Combination Figure 1 This embodiment provides a glass cap-ceramic tube shell hermetic packaging structure, including: a ceramic tube shell 2 with a cavity and a glass cap 1 suitable for covering the opening of the cavity; wherein, the bottom of the glass cap 1 is connected to the upper end of the ceramic tube shell 2 by conductive silver paste 5, and the edge of the glass cap 1 is sealed to the ceramic tube shell 2 by an organosilicon epoxy composite adhesive 6.

[0017] Combination Figures 1 to 3As shown, in this embodiment, the ceramic shell 2 is formed by stacking multiple layers of ceramic, and the multiple ceramic structures are fixedly connected by metallization. A gold-plated layer 7 is provided on the surface of the top of the ceramic shell 2 that connects with the glass cover 1, the purpose of which is to increase the bonding force between the ceramic shell 2 and the glass. The bottom pad of the ceramic shell 2 is connected to its internal circuitry, and the cavity of the ceramic shell 2 has a gold-plated layer 7 for mounting the IC3, which is connected to the electrode 8 via gold wires. The connection between the pad and the internal circuitry is prior art and not the focus of this application, so it will not be elaborated here. A cavity is formed inside the ceramic shell 2, and the glass cover 1 is adapted to cover the opening of the cavity. Specifically, the glass cover 1 is positioned above the ceramic shell 2, and its edges are located inside the shell edge at the top of the ceramic shell 2. The surface of the glass cover 1 is provided with a gold-plated layer 7 that matches the ceramic shell 2 to increase the bonding force. Through this sealing connection scheme, it can be ensured that the airtightness is not compromised after reflow soldering at approximately 250°C, and that it can withstand immersion at 125°C. It does not leak air for 1 minute in a fluorinated liquid at a depth of 200mm, meeting the sealing requirements.

[0018] An IC3 is mounted on the bottom of the ceramic housing 2 cavity and connected to an electrode 8 via a gold wire. A light-emitting IC4, opposite to the IC3, is disposed in the central area of ​​the glass cover 1 surface, and the light-emitting IC4 is connected to the electrode 8 via a gold wire. Preferably, the center of the reflective area of ​​the IC3 coincides with the center of the light-emitting IC4. Here, the IC3 and the light-emitting IC4 are respectively disposed on the gold plating layer 7 at the bottom of the ceramic housing 2 cavity and on the gold plating layer 7 of the glass cover 1. The gold plating layer, IC3, and light-emitting IC4 are connected to the electrode 8 inside the cavity via gold wires. The electrode 8 is then connected to the pads at the bottom of the ceramic housing 2, thus eliminating the need for internal wiring to the outside and improving sealing performance.

[0019] During assembly, first apply silver paste to the inside of the ceramic tube shell 2 and attach IC3. Then apply conductive silver paste 5 to the glass cover 1 and attach the light-emitting IC4. Next, solder IC3 and the light-emitting IC4 to the electrode 8 with gold wire. Then align and assemble the glass cover 1 and the ceramic tube shell 2. Finally, apply silicone epoxy composite adhesive 6 to connect and cure to form a seal.

[0020] The sealing solution in this embodiment achieves a seal between the edge of the glass cover 1 and the ceramic tube shell 2 using a silicone epoxy composite sealant. This ensures that the airtightness between the ceramic tube shell 2 cavity and the glass cover 1 meets the requirements and also solves the problem of flow. The silicone epoxy composite sealant has a surface drying time of 10 minutes at room temperature and can be fully cured after 24 hours at room temperature without heating, which can reduce process costs. The silicone epoxy composite sealant has a surface hardness of 35~45 degrees (Shore hardness), which is relatively soft and can, to some extent, offset or buffer the pressure generated by the temperature rise of the ceramic tube shell 2 cavity during reflow soldering, thus protecting its airtightness to the greatest extent. At the same time, the silicone epoxy composite sealant has an applicable temperature range of -60℃ to 250℃, which can meet most application scenarios.

[0021] It should be understood that the above are only preferred embodiments of the present utility model, and the protection scope of the present utility model is not limited to the above embodiments. All technical solutions that fall within the scope of the present utility model are protected by the present utility model.

[0022] The accompanying drawings used in the above description of the embodiments only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

Claims

1. A glass cap-ceramic tube shell hermetically sealed structure, characterized in that, include: A ceramic tube shell with a cavity and a glass cover suitable for covering the opening of the cavity; wherein the bottom of the glass cover is connected to the upper end of the ceramic tube shell by conductive silver paste, and the edge of the glass cover is sealed to the ceramic tube shell by an organosilicon epoxy composite adhesive.

2. The glass cap-ceramic tube shell hermetically sealed structure according to claim 1, characterized in that, The ceramic tube shell has a multi-layer ceramic structure, and the surface at the top that connects with the glass cover has a gold-plated layer. The surface of the glass cover has a matching gold-plated layer to increase the bonding strength of the connection.

3. The glass cap-ceramic tube shell hermetically sealed structure according to claim 2, characterized in that, An IC is attached to the bottom of the ceramic tube cavity and connected to an electrode via a gold wire; a light-emitting IC is disposed in the central area of ​​the glass cover surface, opposite to the IC, and the light-emitting IC is connected to an electrode via a gold wire.

4. The glass cap-ceramic tube shell hermetically sealed structure according to claim 3, characterized in that, The center of the IC reflection area coincides with the center of the light-emitting IC.

5. The glass cap-ceramic tube shell hermetically sealed structure according to claim 3, characterized in that, The IC and the light-emitting IC are disposed on the gold-plated layer.

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