Multi-layer composite board airtight package and preparation method thereof

Abstract

The invention relates to the technical field of radar communication, and provides a multilayer composite board airtight package and a preparation method thereof. Comprising a multi-layer composite board and a metal shielding cover, the multi-layer composite board comprises a high-frequency circuit layer, a power supply layer, a signal processing control layer and a ground layer, the high-frequency circuit layer and the stratum, the stratum and the power supply layer, and the stratum and the signal processing control layer are connected in a press fit mode. An opening of the metal shielding cover faces downwards, and the edge of the opening of the metal shielding cover is connected with the upper surface of the first high-frequency circuit layer through soldering tin; the CMOS chip is located in the metal shielding cover and connected with the high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer. According to the invention, the defects of large volume, heavy weight and low integration level of a metal shell in the prior art can be effectively overcome.

Description

Technical Field

[0001] The present invention relates to the field of radar communication technology, and in particular to a multi-layer composite plate airtight package and a preparation method thereof. Background Art

[0002] As the application field of radar communication equipment continues to expand, its use environment is also becoming increasingly diverse, which puts higher requirements on the protection level and use conditions of the equipment. Traditional packaging methods mostly use metal materials as sealing carriers. Although it can meet certain sealing requirements, traditional metal packaging generally has problems such as large size, heavy weight, and low integration, which cannot meet the needs of modern equipment for lightness, compactness, and versatility. Therefore, there is an urgent need for a solution that can improve the airtightness of the package, light weight, and high structural integration to meet the use requirements in complex environments.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the conventional hermetic packaging has a large mass and a low integration level.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] In the first aspect, a multi-layer composite board airtight package is proposed, comprising: a multi-layer composite board and a metal shielding cover; the multi-layer composite board comprises: a high-frequency circuit layer located on the first and third layers, a power supply layer located on the first, fifth and seventh layers, a signal processing control layer located on the first, ninth and eleventh layers, and a ground layer located on the first, second, fourth, sixth, eighth and tenth layers; the high-frequency circuit layer and the ground layer, the ground layer and the power supply layer, and the ground layer and the signal processing control layer are all connected by pressing; the opening of the metal shielding cover faces downward, and the edge of the opening of the metal shielding cover is soldered to the upper surface of the high-frequency circuit layer located on the first layer; the CMOS chip is located in the metal shielding cover, and the CMOS chip is respectively connected to the high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer.

[0007] Furthermore, the multi-layer composite board also includes: a plugging and sealing layer; the plugging and sealing layer is arranged on each side wall of the multi-layer composite board in a copper-plated and gold-plated plugging manner.

[0008] Furthermore, the high-frequency circuit layer on the first layer is connected to the ground layers on the second layer, the fourth layer, the sixth layer, the eighth layer and the tenth layer by using a blind hole process.

[0009] Furthermore, an isolation ground hole is provided between the high-frequency circuit layer on the first layer and the signal processing control layer on the ninth and eleventh layers; and conformal coating is added on the upper surface and side walls of the high-frequency circuit layer on the first layer by copper plating.

[0010] Furthermore, the material of the metal shielding cover is Kovar alloy; the surface of the metal shielding cover includes a gold-plated layer.

[0011] In a second aspect, a method for preparing a hermetic package of a multilayer composite board is proposed, comprising the following steps: selecting eleven composite boards and numbering each composite board in sequence; processing the first composite board into a high-frequency circuit layer, a power supply layer, a signal processing control layer and a ground layer, processing the third composite board into a high-frequency circuit layer, processing the fifth composite board and the seventh composite board into a power supply layer, processing the ninth composite board and the eleventh composite board into a signal processing control layer, and processing the second composite board, the fourth composite board, the sixth composite board, the eighth composite board and the tenth composite board into a ground layer; stacking and pressing the high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer in the corresponding numbering order to obtain a multilayer composite board; placing a CMOS chip on the upper surface of the multilayer composite board, and connecting the CMOS chip to the high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer respectively; placing a metal shielding cover upside down on the upper surface of the multilayer composite board so that the COMOS chip is located in the metal shielding cover, and soldering the edge of the opening of the metal shielding cover to the upper surface of the composite board.

[0012] Furthermore, the method for preparing the multi-layer composite board airtight package further comprises the following steps: laying a plugging and sealing layer on each side wall of the multi-layer composite board by means of copper-plated and gold-plated plugging holes.

[0013] Furthermore, the method for preparing the multi-layer composite plate airtight package also includes the following steps: using a blind hole process to connect the first composite plate with the second composite plate, the fourth composite plate, the sixth composite plate, the eighth composite plate and the tenth composite plate respectively.

[0014] Furthermore, the method for preparing the multi-layer composite panel airtight package also includes the following steps: setting isolation ground holes between the first composite panel and the ninth composite panel and between the first composite panel and the eleventh composite panel, respectively; adding conformal coating on the upper surface of the first composite panel and each side wall of the first composite panel by copper plating.

[0015] Furthermore, the method for preparing the multi-layer composite plate airtight package further comprises the following steps: gold plating on the surface of the metal shielding cover.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] 1. Organically combine multi-layer composite board structure and multiple sealing technologies. On the one hand, the use of multi-layer composite board to replace metal materials as the outer frame achieves airtight effect. Compared with traditional airtight packaging, it is lighter in weight under the same external dimensions. On the other hand, the composite board is made of multi-layer composite materials pressed together, and each layer is designed in layers according to its function. The signal transmission between layers is connected by cross-staggered feeding, which improves the product integration and realizes the high sealing, lightweight and integrated improvement of radar communication equipment.

[0018] 2. The gaps between the layers on the side of the composite board are sealed by copper plating and gold plugging, which reduces the airtight leakage rate between layers; and the shielding cover is made of high-strength Kovar alloy material and then gold-plated and connected to the multi-layer composite board surface with tin to achieve sealing between the shielding cover and the multi-layer composite board, reducing the airtight leakage rate after sealing.

[0019] 3. The high-frequency circuit layer on the surface of the composite board is connected to the internal layers using a blind hole process to increase the continuity between ground layers and expand the heat dissipation area and heat dissipation path.

[0020] 4. The inter-layer signal transmission adopts the cross-staggered feeding connection, and a ground layer is added around the feeding port to effectively isolate the mutual interference of signals between layers and holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic structural diagram of a multi-layer composite plate airtight package provided in an embodiment of the present invention.

[0023] Marks and corresponding parts names in the attached drawings:

[0024] 1- multi-layer composite board, 2- metal shielding cover, 11- high frequency circuit layer, 12- power supply layer, 13- signal processing control layer, 14- ground layer, 15- plugging and sealing layer, 21- gold-plated layer. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0026] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other embodiments, in order to avoid obscuring the present invention, well-known structures, circuits, materials, or methods are not specifically described.

[0027] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] In the description of the present invention, the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, “vertical”, “horizontal”, “high”, “low”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.

[0029] Embodiment: Provide a multi-layer composite plate airtight package, the airtight package as Figure 1 shown.

[0030] 1. Basic structure

[0031] In a possible embodiment, the multilayer composite board airtight package includes a multilayer composite board 1 and a metal shielding cover 2. The multilayer composite board 1 is composed of a high-frequency circuit layer 11, a power supply layer 12, a signal processing control layer 13 and a ground layer 14. Specifically, the high-frequency circuit layer 11 is located on the first and third layers, the power supply layer 12 is located on the first, fifth and seventh layers, the signal processing control layer 13 is located on the first, ninth and eleventh layers, and the ground layer 14 is located on the first, second, fourth, sixth, eighth and tenth layers. The layers are connected by a pressing process to ensure the airtightness and stability between the layers. The opening of the metal shielding cover 2 faces downward, and its edge is sealed and connected to the upper surface of the high-frequency circuit layer 11 of the first layer by soldering. A CMOS chip 3 is installed inside the shielding cover 2, and the CMOS chip 3 is electrically connected to the high-frequency circuit layer 11, the power supply layer 12, the signal processing control layer 13 and the ground layer 14 in the multilayer composite board.

[0032] The airtight package ensures stable operation of radar communication equipment in harsh environments through the rational arrangement of multi-layer composite plate structures and the application of multiple sealing technologies, combined with metal shielding covers and protective coatings. The high-integration, lightweight seal achieves interlayer isolation and mutual shielding of the high-frequency circuit layer, power supply layer, signal processing control layer and the ground layer, effectively improving the protection level of the airtight package.

[0033] 2. Sealing layer structure

[0034] Based on the above basic structure, the airtight packaged multi-layer composite board 1 further includes a plugging sealing layer 15. The plugging sealing layer 15 is arranged on the side wall of the multi-layer composite board 1 in the form of copper-plated gold-plated plug holes.

[0035] Between the layers of the multi-layer composite board, the side gaps are sealed by copper plating and gold plugging process, which effectively improves the airtightness. The sealing treatment between the layers makes the interlayer airtight leakage rate reach less than 1×10 -10 Pa.m3 / s, suitable for high-demand radar communication equipment. This airtight design not only prevents the penetration of air and moisture, but also prevents the influence of external corrosive gases on the internal circuit, significantly improving the durability of the equipment.

[0036] 3. Application of blind hole process

[0037] This embodiment further optimizes the connection structure between the high-frequency circuit layer 11 and the ground layer 14. Specifically, the high-frequency circuit layer 11 on the first layer is connected to the second, fourth, sixth, eighth and tenth ground layers 14 using a blind hole process.

[0038] The ground layer in the multi-layer composite board is connected to the outer high-frequency circuit layer through the blind hole process. The application of the blind hole process not only reduces the mutual interference between the circuit layers, but also improves the stability and reliability of signal transmission. In addition, the blind hole structure also enhances the continuity of the ground layer, expands the area of ​​the heat dissipation channel, and optimizes the heat dissipation path of the equipment, which is particularly suitable for the heat dissipation requirements of high-power circuits. It not only effectively reduces the operating temperature, but also ensures the stability of the equipment under high-temperature working conditions.

[0039] 4. Isolation design and three-proof treatment

[0040] In order to further improve the isolation effect of each circuit layer, an isolation ground hole is set between the first high-frequency circuit layer 11 and the ninth and eleventh signal processing control layers 13. At the same time, a three-proof paint is added to the upper surface and side wall of the high-frequency circuit layer 11.

[0041] Signal transmission is achieved between the layers inside the multi-layer composite board through staggered feeding, and a ground layer is added around the feeding interface. This structure can significantly reduce mutual interference between signals and effectively isolate signal transmission between different layers and holes, thereby improving the signal stability and transmission efficiency of the device. This innovative structure of staggered feeding has great technical advantages in high-frequency signal transmission and ensures the reliability of the device under high-density wiring conditions.

[0042] 5. Materials and surface treatment of metal shielding cover

[0043] In this embodiment, the metal shielding cover 2 is made of Kovar alloy material, and a gold-plated layer 21 is plated on its surface to improve the corrosion resistance and oxidation resistance of the shielding cover, and also further improve its electromagnetic shielding effect.

[0044] The metal shield is made of high-strength Kovar alloy and is gold-plated on its surface to enhance its anti-oxidation and anti-corrosion capabilities. The gold-plated layer design not only improves the durability of the shield, but also ensures airtightness and shielding performance. The shield is sealed with solder to the multi-layer composite board, and the airtightness after sealing is less than 1×10 -9 Pa.m 3 / s, suitable for long-term work in a vacuum environment.

[0045] In addition, the application of the three-proof coating can isolate the impact of moisture, corrosive gases and mold on the equipment, further extending the service life of the composite board. This physical isolation design ensures the protection ability of the composite board, making it suitable for use in harsh environments such as humidity and high salt fog.

[0046] According to the above structure, the method for preparing the multi-layer composite plate airtight package of the present invention comprises the following steps:

[0047] Step 1: Select eleven composite panels and number each composite panel sequentially.

[0048] Step 2: Process the first composite board into a high-frequency circuit layer, a power supply layer, a signal processing control layer and a ground layer, process the third composite board into a high-frequency circuit layer, process the fifth composite board and the seventh composite board into a power supply layer, process the ninth composite board and the eleventh composite board into a signal processing control layer, and process the second composite board, the fourth composite board, the sixth composite board, the eighth composite board and the tenth composite board into a ground layer.

[0049] Step 3: Stack and press the high-frequency circuit layer, power supply layer, signal processing control layer and ground layer together in the corresponding numbering order to obtain a multi-layer composite board.

[0050] Step 4: Place the CMOS chip on the upper surface of the multi-layer composite board, and connect the CMOS chip to the high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer respectively.

[0051] Step 5: Place the metal shield cover upside down on the upper surface of the multi-layer composite board so that the COMOS chip is located inside the metal shield cover, and connect the edge of the opening of the metal shield cover to the upper surface of the composite board by soldering.

[0052] Improvement of the preparation method: Based on the above method, the following steps may be further included: a sealing layer is laid on each side wall of the multi-layer composite board, and the high-frequency circuit layer of the first layer is connected to the second composite board, the fourth composite board, the sixth composite board, the eighth composite board and the tenth composite board through a blind hole process. In addition, isolation holes are set between the first composite board and the ninth composite board and between the first composite board and the eleventh composite board, and the surface of the metal shielding cover is gold-plated to improve its anti-oxidation performance and corrosion resistance, and a three-proof paint treatment is added to the upper surface and side wall of the high-frequency circuit layer.

[0053] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-layer composite plate airtight package, characterized in that: include: A multilayer composite plate (1) and a metal shielding cover (2); The multilayer composite board (1) comprises: a high-frequency circuit layer (11) located on the first and third layers, a power supply layer (12) located on the first, fifth and seventh layers, a signal processing control layer (13) located on the first, ninth and eleventh layers, and a ground layer (14) located on the first, second, fourth, sixth, eighth and tenth layers; the high-frequency circuit layer (11) and the ground layer (14), the ground layer (14) and the power supply layer (12), and the ground layer (14) and the signal processing control layer (13) are all connected by pressing; the opening of the metal shielding cover (2) faces downward, and the edge of the opening of the metal shielding cover (2) is solder-connected to the upper surface of the high-frequency circuit layer (11) located on the first layer; a CMOS chip (3) is located in the metal shielding cover (2), and the CMOS chip (3) is respectively connected to the high-frequency circuit layer (11), the power supply layer (12), the signal processing control layer (13) and the ground layer (14).

2. The multi-layer composite plate airtight package according to claim 1, characterized in that: The multilayer composite board (1) further comprises: a plugging sealing layer (15); the plugging sealing layer (15) is arranged on each side wall of the multilayer composite board (1) in a copper-plated and gold-plated plugging manner.

3. A multi-layer composite plate airtight package according to claim 1 or 2, characterized in that: The high-frequency circuit layer (1) located on the first layer and the ground layers (14) located on the second layer, the fourth layer, the sixth layer, the eighth layer and the tenth layer are connected by a blind hole process.

4. A multi-layer composite plate airtight package according to claim 1 or 2, characterized in that: An isolation ground hole is provided between the high-frequency circuit layer (11) located on the first layer and the signal processing control layer (13) located on the ninth layer and the eleventh layer; and conformal coating is added to the upper surface and side wall of the high-frequency circuit layer (11) located on the first layer by copper plating.

5. A multi-layer composite plate airtight package according to claim 1 or 2, characterized in that: The material of the metal shielding cover (2) is Kovar alloy; the surface of the metal shielding cover (2) includes a gold-plated layer (21).

6. A method for preparing a multi-layer composite plate airtight package, characterized in that: The following steps are involved: Select eleven composite boards and number each composite board sequentially; Processing the first composite board into a high-frequency circuit layer, a power supply layer, a signal processing control layer and a ground layer, processing the third composite board into a high-frequency circuit layer, processing the fifth composite board and the seventh composite board into a power supply layer, processing the ninth composite board and the eleventh composite board into a signal processing control layer, and processing the second composite board, the fourth composite board, the sixth composite board, the eighth composite board and the tenth composite board into a ground layer; The high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer are stacked and pressed together in the corresponding numbering sequence to obtain a multi-layer composite board; Placing the CMOS chip on the upper surface of the multi-layer composite board, and connecting the CMOS chip to the high-frequency circuit layer, the power supply layer, the signal processing control layer and the ground layer respectively; Place the metal shield cover upside down on the upper surface of the multi-layer composite board, so that the COMOS chip is located inside the metal shield cover, and connect the edge of the opening of the metal shield cover to the upper surface of the composite board by soldering.

7. The method for preparing a multi-layer composite plate airtight package according to claim 6, characterized in that: The following steps are also included: A plugging and sealing layer is laid on each side wall of the multi-layer composite board by means of copper-plated gold-plated plugging holes.

8. The method for preparing a multi-layer composite plate airtight package according to claim 6 or 7, characterized in that: The following steps are also included: The first composite board is connected to the second composite board, the fourth composite board, the sixth composite board, the eighth composite board and the tenth composite board respectively by using a blind hole process.

9. The method for preparing a multi-layer composite plate airtight package according to claim 6 or 7, characterized in that: The following steps are also included: Isolation holes are respectively provided between the first composite plate and the ninth composite plate and between the first composite plate and the eleventh composite plate; The three-proof coating is added on the upper surface of the first composite board and each side wall of the first composite board by copper plating.

10. The method for preparing a multi-layer composite plate airtight package according to claim 6 or 7, characterized in that: The following steps are also included: The surface of the metal shield is plated with gold.

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