Airtight packaging method for double-sided interconnection ceramic packaging SiP

Abstract

The invention discloses a double-sided interconnection ceramic package SiP airtight packaging method. The method comprises the following steps: providing a planar ceramic cover plate and a three-dimensional ceramic bottom plate; manufacturing a limiting solder mask layer at the bottom end of the planar ceramic cover plate; a solder layer limited by the limited solder mask layer is preset at the bottom end of the planar ceramic cover plate at low temperature; and oppositely stacking the planar ceramic cover plate and the three-dimensional ceramic bottom plate to enable the enclosure frame structure and the plurality of cylindrical structures to abut against the solder layer, and then carrying out eutectic soldering to obtain an airtight double-sided interconnected ceramic package SiP product. According to the method, a limiting solder mask mode is adopted, the limiting solder mask layer is manufactured on the planar ceramic cover plate, the solder layer is limited, and meanwhile, the overflow state of the molten solder layer can be effectively controlled, so that a welding cavity caused by displacement and overflow of the solder layer is avoided, and the preset precision of the solder layer and the airtight performance of a ceramic package SiP are improved; the welding flux layer is fixed in a low-temperature preset mode, and the problem of displacement of the welding flux layer is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronic packaging, and in particular relates to a double-sided interconnected ceramic package SiP hermetic packaging method. Background Art

[0002] With the rapid development of electronic information technology, high-density integration and miniaturization of devices and circuits have become important development trends. Three-dimensional integration technology based on SiP (System-in-Package) is a key approach to achieving miniaturization and multifunctionality in electronic systems. Ceramic SiPs utilize a vertical stacking process to integrate multiple chips, devices, and passive components within a single ceramic package. This highly integrated and airtight SiP is the most widely used high-reliability packaging structure.

[0003] A ceramic SiP package consists of a base plate and a cover plate, both of which are ceramic substrates. Both ends of the base plate and cover plate have interconnecting circuit patterns and pads, and double-sided interconnection is achieved through interconnecting copper pillars and BGA balls. For example, patent publication number CN114597176A discloses a double-sided interconnected three-dimensional ceramic package structure. The package shell primarily comprises a planar ceramic substrate and a three-dimensional ceramic substrate. The three-dimensional ceramic substrate contains metal micropillars for electrical interconnection between the upper and lower ceramic substrates, and a metal frame for hermetic sealing. Gold-tin solder is used to achieve interconnection and airtightness between the metal micropillars, the metal frame, and the planar ceramic substrate.

[0004] However, the metal micropillars and metal frame are independent, small-sized (0.2-0.6mm), making solder pad shifting a common problem during assembly. This can lead to uneven solder distribution at the interface, and in severe cases, can even create through-hole voids. This means that pre-positioning solder pads is not only a crucial step in ensuring package airtightness but also a major factor impacting production efficiency. Furthermore, overflow from the melted gold-tin solder pad during soldering can lead to uneven solder distribution at the interface and even create voids. Controlling gold-tin solder overflow is also crucial for ensuring airtightness in soldering.

[0005] As ceramic SiPs extend their service life, their airtightness directly impacts the electrical performance and reliability of the product. Therefore, for widespread adoption of ceramic SiPs, pre-positioning solder pads and controlling gold-tin solder overflow have become pressing challenges in achieving hermetic packaging. Summary of the Invention

[0006] In order to overcome the defects of the prior art, the present invention provides a double-sided interconnected ceramic package SiP hermetic packaging method, which can improve the hermetic performance of the ceramic package SiP.

[0007] The object of the present invention is achieved through the following technical solutions: A double-sided interconnected ceramic package SiP hermetic packaging method comprises the following steps: A flat ceramic cover plate and a three-dimensional ceramic base plate are provided, wherein the top of the three-dimensional ceramic base plate is provided with a frame structure and a plurality of cylindrical structures; A limited solder resist layer is formed at the bottom end of the flat ceramic cover plate; A solder layer limited by a limited solder resist layer is pre-set at the bottom end of the planar ceramic cover plate, wherein the working temperature during pre-setting is lower than the melting point of the solder layer; The flat ceramic cover plate and the three-dimensional ceramic bottom plate are stacked relative to each other so that the surrounding frame structure and the plurality of cylindrical structures abut against the solder layer, and then eutectic welding is performed.

[0008] The beneficial effects of adopting the above technical solution are: the limiting solder mask layer limits the solder layer, and at the same time can effectively control the overflow state of the solder layer after melting, so as to avoid welding voids caused by displacement and overflow of the solder layer, thereby helping to improve the airtightness performance of the ceramic package SiP.

[0009] Furthermore, between the formation of the limited solder resist layer at the bottom end of the planar ceramic cover plate and the pre-positioning of the solder layer limited by the limited solder resist layer at the bottom end of the planar ceramic cover plate, the following steps are also included: A plurality of first chips and a plurality of second chips are respectively mounted on the bottom end of the planar ceramic cover plate and the top end of the three-dimensional ceramic base plate; A plurality of first chips are interconnected with the planar ceramic cover plate through gold wires, and a plurality of second chips are interconnected with the three-dimensional ceramic base plate through gold wires.

[0010] Furthermore, forming a limiting solder resist layer at the bottom end of the planar ceramic cover plate includes: Making a plurality of first limiting solder resist rings and second limiting solder resist rings at the bottom end of the planar ceramic cover plate; The solder layer limited by the limited position solder resist layer pre-set at the bottom end of the flat ceramic cover plate includes: A plurality of first welding pieces for eutectic welding cylindrical structures and second welding pieces for eutectic welding frame structures are pre-installed at the bottom end of the planar ceramic cover plate, wherein the first welding pieces are limited by the first limiting solder resist ring and the second welding pieces are limited by the second limiting solder resist ring.

[0011] Furthermore, the second welding piece includes a welding piece body, the horizontal cross-sectional dimension of the welding piece body matches the horizontal cross-sectional dimension of the frame structure, and a plurality of welding piece sacrificial structures are arranged in an array on the inner and outer sides of the welding piece body along the inner circumference direction and the outer circumference direction respectively.

[0012] Furthermore, the horizontal cross-section of the sacrificial structure of the solder tab is semicircular, rectangular or triangular.

[0013] Furthermore, the first solder pad is limited by the first limiting solder resist ring, including: The first limiting solder resist ring limits the outer side of the first solder piece; The second solder tab is limited by the second limiting solder resist ring, including: The second limiting solder resist ring limits the inner side of the second solder piece.

[0014] Furthermore, forming a limiting solder resist layer at the bottom end of the planar ceramic cover plate includes: A limit solder resist layer is screen printed on the bottom of the flat ceramic cover.

[0015] Furthermore, pre-setting a solder layer limited by a limited position solder resist layer at the bottom end of the planar ceramic cover plate includes: On a hot plate with a working temperature lower than the melting point of the solder layer, the solder layer is placed on the bottom end of the flat ceramic cover plate, and pressure is applied to the solder layer to fix the solder layer on the flat ceramic cover plate.

[0016] Furthermore, the planar ceramic cover plate and the three-dimensional ceramic base plate are stacked relative to each other so that the frame structure and the plurality of cylindrical structures abut against the solder layer, and then eutectic welding is performed, including: The flat ceramic cover plate and the three-dimensional ceramic base plate are stacked relative to each other in a welding fixture, and the welding fixture is placed in a vacuum eutectic furnace to eutectic weld the frame structure and several cylindrical structures on the three-dimensional ceramic base plate to the flat ceramic cover plate. Furthermore, circuit patterns and pads are provided at both ends of the planar ceramic cover plate and the three-dimensional ceramic base plate.

[0017] The beneficial effects of the present invention are: A limited solder resist method is used to make a limited solder resist layer on the flat ceramic cover to limit the solder layer. At the same time, it can effectively control the overflow state of the solder layer after melting, so as to avoid solder voids caused by solder layer displacement and overflow, thereby improving the preset accuracy of the solder layer and the airtightness of the ceramic package SiP; The solder layer is fixed by low-temperature presetting, which solves the problem of solder layer displacement. Compared with the method of presetting the solder piece by remelting, it avoids the problem of solder composition change caused by remelting the solder piece, thereby avoiding the impact on the airtight packaging yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein: Figure 1 shows a flow chart of the present invention; Figure 2 Shows a schematic structural diagram of a double-sided interconnected ceramic package SiP product of the present invention; Figure 3 Shows a schematic structural diagram of the three-dimensional ceramic base plate of the present invention; Figure 4Shows a schematic structural diagram of the flat ceramic cover plate of the present invention; Figure 5 It shows a schematic structural diagram of a flat ceramic cover plate after manufacturing a limited solder resist layer according to the present invention; Figure 6 It shows a schematic structural diagram of the three-dimensional ceramic base plate after assembling the second chip of the present invention; Figure 7 It shows a schematic structural diagram of the flat ceramic cover plate after assembling the first chip according to the present invention; Figure 8 It shows a schematic structural diagram of a flat ceramic cover plate after pre-setting a solder layer according to the present invention; Figure 9 A schematic diagram of stacking during eutectic welding of the present invention is shown; Figure 10 A schematic diagram showing a first structure of the second welding piece in the present invention is shown; Figure 11 A second structural schematic diagram of the second welding piece in the present invention is shown; Figure 12 A third structural schematic diagram of the second welding piece of the present invention is shown; In the drawings, like reference numerals are used for like parts, but the drawings are not necessarily true to scale.

[0019] Reference numerals: 1. Three-dimensional ceramic base plate; 2. Flat ceramic cover plate; 3. Frame structure; 4. Cylindrical structure; 5. Position-limiting solder resist layer; 6. Second chip; 7. First chip; 8. First solder pad; 9. Second solder pad; 901. Solder pad body; 902. Solder pad sacrificial structure; 10. Soldering fixture. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] The present invention provides a double-sided interconnected ceramic package SiP hermetic packaging method, such as Figure 1 As shown, it includes the following steps: Provide Figure 4 The flat ceramic cover plate 2 shown and Figure 3 The three-dimensional ceramic base plate 1 shown, wherein a frame structure 3 and a plurality of cylindrical structures 4 are provided on the top of the three-dimensional ceramic base plate 1; like Figure 5 As shown, a limiting solder resist layer 5 is made on the bottom end of the planar ceramic cover plate 2, wherein the bottom end of the planar ceramic cover plate 2 and the top end of the three-dimensional ceramic base plate 1 are both welding surfaces and are arranged relative to each other after eutectic welding; like Figure 8As shown, a solder layer limited by a limited position solder resist layer 5 is preset at the bottom end of the flat ceramic cover plate 2, wherein the working temperature during the preset is lower than the melting point of the solder layer, and the solder layer is gold-tin solder; like Figure 9 As shown, the flat ceramic cover plate 2 and the three-dimensional ceramic base plate 1 are stacked relative to each other so that the frame structure 3 and the plurality of cylindrical structures 4 abut against the solder layer, and then eutectic welding is performed to obtain Figure 2 The hermetic double-sided interconnected ceramic package SiP product shown.

[0022] It can be understood that a limiting solder resist method is adopted to make a limiting solder resist layer 5 on the flat ceramic cover plate 2 to limit the solder layer. At the same time, it can effectively control the overflow state of the solder layer after melting, so as to avoid welding voids caused by displacement and overflow of the solder layer, thereby helping to improve the preset accuracy of the solder layer and the airtight performance of the ceramic package SiP.

[0023] It should be noted that the planar ceramic cover plate 2 and the three-dimensional ceramic base plate 1 are arranged relative to each other to form an airtight closed chamber by welding, and the bottom and top ends of the planar ceramic cover plate 2 and the three-dimensional ceramic base plate 1 have circuit patterns and pads for double-sided interconnection.

[0024] In one embodiment, Figure 5-8 As shown, between the production of the position-limiting solder resist layer 5 at the bottom end of the planar ceramic cover plate 2 and the pre-positioning of the solder layer limited by the position-limiting solder resist layer 5 at the bottom end of the planar ceramic cover plate 2, the following steps are also included: A plurality of first chips 7 and a plurality of second chips 6 are fixed to corresponding pads at the bottom end of the planar ceramic cover plate 2 and the top end of the three-dimensional ceramic base plate 1 respectively through a micro-assembly process; A plurality of first chips 7 are interconnected with the planar ceramic cover plate 2 through gold wires, and a plurality of second chips 6 are interconnected with the three-dimensional ceramic base plate 1 through gold wires.

[0025] It should be noted that since baking treatment will be performed during the microassembly of the first chip 7 and the second chip 6, the microassembly process of the first chip 7 and the second chip 6 is set before the pre-set solder layer to avoid the temperature during the baking treatment affecting the solder layer.

[0026] In one embodiment, Figure 5 and Figure 8 As shown, the process of making the limiting solder resist layer 5 at the bottom end of the planar ceramic cover plate 2 includes: Make a plurality of first limiting solder resist rings and second limiting solder resist rings at the bottom end of the planar ceramic cover plate 2; The solder layer limited by the limited position solder resist layer 5 is pre-set at the bottom end of the flat ceramic cover plate 2 and includes: A plurality of first welding pieces 8 for eutectic welding of the cylindrical structure 4 and second welding pieces 9 for eutectic welding of the frame structure 3 are pre-installed at the bottom end of the planar ceramic cover plate 2, wherein the first welding pieces 8 are limited by the first limiting solder resist ring and the second welding pieces 9 are limited by the second limiting solder resist ring.

[0027] In one embodiment, Figure 10-12 As shown, the second welding piece 9 includes a welding piece body 901, the horizontal cross-sectional dimensions of the welding piece body 901 match the horizontal cross-sectional dimensions of the frame structure 3, and a plurality of welding piece sacrificial structures 902 are arranged in an array on the inner and outer sides of the welding piece body 901 along the inner circumference direction and the outer circumference direction respectively. The welding piece body 901 and the welding piece sacrificial structure 902 are hollowed out and interconnected; preferably, the horizontal cross-sectional shape of the welding piece sacrificial structure 902 is semicircular, rectangular or triangular; the width of the area where the welding piece sacrificial structure 902 is located on the inner and outer sides of the welding piece body 901 is 10um~80um; such a design can not only ensure that after the welding piece sacrificial structure 902 melts, the solder shrinks and accumulates around the welds on the inner and outer sides of the frame structure 3, thereby solving the problem of through-holes formed on the welding surface of the frame structure 3 due to uneven distribution of solder, ensuring airtight welding, but also avoid the interconnection short circuit problem caused by solder overflow due to excessive solder.

[0028] In one embodiment, the first solder tab 8 is limited by the first limiting solder resist ring including: The first limiting solder resist ring limits the outer side of the first solder piece 8; The second soldering piece 9 is limited by the second limiting solder resist ring including: The second limiting solder resist ring limits the inner side of the second solder piece 9 .

[0029] It should be noted that the outer edge of the bottom end of the planar ceramic cover plate 2 is made of ceramic with a width of 50 μm to 200 μm. During the eutectic process, the ceramic acts as a solder resist and can effectively limit the overflow of the solder.

[0030] In one embodiment, forming a limiting solder resist layer 5 at the bottom end of the planar ceramic cover plate 2 includes: A limiting solder resist layer 5 is screen-printed on the bottom end of the planar ceramic cover plate 2 .

[0031] In one embodiment, the solder layer limited by the limited position solder resist layer 5 is pre-set at the bottom end of the planar ceramic cover plate 2 and includes: On a hot plate with a working temperature lower than the melting point of the solder layer, the solder layer is placed on the corresponding pad at the bottom end of the planar ceramic cover plate 2. The limiting solder resist layer 5 around the pad limits the solder layer, and then a certain pressure is applied to the solder layer to fix the solder layer on the planar ceramic cover plate 2.

[0032] Specifically, the operating temperature of the hot plate should be 20°C to 100°C lower than the melting point of the solder layer. Such a setting can not only ensure that the first soldering piece 8 and the second soldering piece 9 are fixed to the soldering pad under pressure, avoiding the problem of displacement of the first soldering piece 8 and the second soldering piece 9 during assembly, but also avoid the problem of remelting of the first soldering piece 8 and the second soldering piece 9, so as to ensure the airtight effect of welding.

[0033] In addition, the first welding piece 8 and the second welding piece 9 are placed on the corresponding welding pads on the planar ceramic cover plate 2, and the first welding piece 8 and the second welding piece 9 are respectively limited by the first limiting solder mask ring and the second limiting solder mask ring around the welding pads, and then a pressure of 10g~100g is applied to fix the first welding piece 8 and the second welding piece 9 on the corresponding welding pads on the planar ceramic cover plate 2.

[0034] It should be noted that, when pre-depositing the solder layer, the bottom end of the planar ceramic cover plate 2 faces upwards to facilitate placement of the first soldering piece 8 and the second soldering piece 9 .

[0035] It should also be noted that the thickness of the limiting solder resist layer 5 is 20um~90um, the pad area defined by the first limiting solder resist ring is 10um~80um larger than the diameter of the cylindrical structure 4, and the pad area defined by the second limiting solder resist ring is 10um~80um larger than the line width of the frame structure 3; such a design can not only limit the solder layer during the pre-setting process of the solder layer, but also control the overflow of the solder after melting, so that the melted solder is evenly distributed on the edge of the weld, ensuring the welding air tightness and the reliability of electrical interconnection.

[0036] In addition, the thickness of the first solder sheet 8 and the second solder sheet 9 used in the pre-solder layer is 20um~100um. Such a design can avoid both the problem of solder voids caused by insufficient solder and the problem of solder short circuits caused by excessive solder.

[0037] In one embodiment, the planar ceramic cover plate 2 and the three-dimensional ceramic base plate 1 are stacked relative to each other so that the frame structure 3 and the plurality of cylindrical structures 4 abut against the solder layer, and then eutectic welding is performed, including: The planar ceramic cover plate 2 and the three-dimensional ceramic base plate 1 are stacked relative to each other in a welding fixture 10, and the welding fixture 10 is placed in a vacuum eutectic furnace so that the frame structure 3 and the plurality of cylindrical structures 4 on the three-dimensional ceramic base plate 1 are eutectic welded to the planar ceramic cover plate 2.

[0038] It should be noted that the planar ceramic cover plate 2 and the three-dimensional ceramic base plate 1 are stacked relative to each other in the welding fixture 10, with the bottom end of the planar ceramic cover plate 2 facing upward and the top end of the three-dimensional ceramic base plate 1 facing downward, so that the cylindrical structure 4 and the frame structure 3 are in close contact with the first welding plate 8 and the second welding plate 9 respectively under the action of their own gravity, which is conducive to improving the welding performance of the cylindrical structure 4 and the frame structure 3 with the planar ceramic cover plate 2.

[0039] It should also be noted that the maximum temperature during eutectic welding is 10℃~50℃ higher than the melting point of the solder layer.

[0040] Here is a packaging example: Figure 1-9 As shown, it includes the following steps: Step 1: providing a planar ceramic cover plate 2 and a three-dimensional ceramic base plate 1 for airtight packaging, wherein the top of the three-dimensional ceramic base plate 1 has a metal frame structure 3 and a metal micro-column cylindrical structure 4; Step 2: a 40 μm thick position limiting solder resist layer 5 is formed on the bottom of the planar ceramic cover plate 2 by screen printing, wherein the position limiting solder resist layer 5 includes a first annular position limiting solder resist ring and a second annular position limiting solder resist ring; Step 3: Using a micro-assembly process, a plurality of first chips 7 and second chips 6 are fixed to corresponding pads on the bottom end of the planar ceramic cover plate 2 and the top end of the three-dimensional ceramic base plate 1, and the plurality of first chips 7 are interconnected with the planar ceramic cover plate 2 through gold wires, and the plurality of second chips 6 are interconnected with the three-dimensional ceramic base plate 1 through gold wires; Step 4: Pre-deposit a solder layer at low temperature; specifically, the solder layer is gold-tin solder, and the solder layer includes a first solder piece 8 and a second solder piece 9 corresponding to the cylindrical structure 4 and the frame structure 3, and the thickness of the solder layer is 70 μm; on a hot plate below 60°C, which is the melting point of the solder layer, the preformed first solder piece 8 and the second solder piece 9 are placed on the corresponding pads at the bottom end of the flat ceramic cover plate 2, and the positions of the first solder piece 8 and the second solder piece 9 are restricted by the limiting solder resist layer 5 around the pads. At the same time, a certain pressure is applied to the center position of the first solder piece 8 and the four corners of the second solder piece 9 to fix the first solder piece 8 and the second solder piece 9 on the corresponding pads; Step 5: The flat ceramic cover plate 2 and the three-dimensional ceramic base plate 1 with the pre-set low-temperature solder layer are stacked relative to each other in the welding fixture 10, and then the welding fixture 10 is placed in a vacuum eutectic furnace to complete the airtight welding; wherein, the maximum temperature of the eutectic welding is set to 320 ° C, and the maximum temperature is kept for 2 minutes to complete the welding, and then cooled to obtain an airtight double-sided interconnected ceramic package SiP product.

[0041] In summary, the present invention adopts a position-limiting solder resist method to form a position-limiting solder resist layer 5 on a flat ceramic cover plate 2 to limit the solder layer. At the same time, it can effectively control the overflow state of the solder layer after melting, so as to avoid solder voids caused by displacement and overflow of the solder layer, thereby facilitating the improvement of the preset accuracy of the solder layer and the airtightness of the ceramic package SiP, and the operation method is simple. The present invention adopts a sacrificial structure mode, and sets the welding piece sacrificial structure 902 in the non-welding area of ​​the second welding piece 9, so that the welding piece sacrificial structure 902 shrinks and accumulates at the weld after melting, thereby improving reliability and airtight packaging yield rate, and the operation method is simple; The present invention adopts a low-temperature presetting method to fix the solder layer, which solves the problem of solder layer displacement. Compared with the method of presetting the solder piece by remelting, it avoids the problem of solder composition change caused by remelting the solder piece, thereby avoiding the impact on the airtight packaging yield. The operation process is simple and suitable for large-scale mass production.

[0042] In the description of the present invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "left", "right", etc., indicating directions or positional relationships, 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, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0043] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with other described embodiments.

Claims

1. A double-sided interconnected ceramic package SiP hermetic packaging method, characterized in that: The following steps are involved: A planar ceramic cover plate (2) and a three-dimensional ceramic base plate (1) are provided, wherein a frame structure (3) and a plurality of cylindrical structures (4) are provided at the top of the three-dimensional ceramic base plate (1); Making a limiting solder resist layer (5) at the bottom end of the flat ceramic cover plate (2); A solder layer limited by a limited position solder resist layer (5) is pre-set at the bottom end of the planar ceramic cover plate (2), wherein the working temperature during pre-setting is lower than the melting point of the solder layer; The flat ceramic cover plate (2) and the three-dimensional ceramic base plate (1) are stacked relative to each other so that the surrounding frame structure (3) and the plurality of cylindrical structures (4) abut against the solder layer, and then eutectic welding is performed.

2. The method for hermetic packaging of a double-sided interconnected ceramic package SiP according to claim 1, characterized in that: The step of forming the position-limiting solder resist layer (5) at the bottom end of the planar ceramic cover plate (2) and the solder layer pre-positioned at the bottom end of the planar ceramic cover plate (2) to limit the position of the position-limiting solder resist layer (5) further includes the following steps: A plurality of first chips (7) and a plurality of second chips (6) are respectively assembled on the bottom end of the planar ceramic cover plate (2) and the top end of the three-dimensional ceramic base plate (1); A plurality of first chips (7) are interconnected with a planar ceramic cover plate (2) through gold wires, and a plurality of second chips (6) are interconnected with a three-dimensional ceramic base plate (1) through gold wires.

3. A double-sided interconnected ceramic package SiP hermetic packaging method according to claim 1 or 2, characterized in that: The method of producing a limiting solder resist layer (5) at the bottom end of the planar ceramic cover plate (2) comprises: Making a plurality of first limiting solder resist rings and second limiting solder resist rings at the bottom end of the planar ceramic cover plate (2); The solder layer limited by the limited position solder resist layer (5) pre-set at the bottom end of the planar ceramic cover plate (2) comprises: A plurality of first welding pieces (8) for eutectic welding of the cylindrical structure (4) and a plurality of second welding pieces (9) for eutectic welding of the frame structure (3) are pre-set at the bottom end of the planar ceramic cover plate (2), wherein the first welding pieces (8) are limited by a first limiting solder resist ring, and the second welding pieces (9) are limited by a second limiting solder resist ring.

4. The method for hermetic packaging of a double-sided interconnected ceramic package SiP according to claim 3, characterized in that: The second welding piece (9) includes a welding piece body (901), the horizontal cross-sectional dimensions of the welding piece body (901) match the horizontal cross-sectional dimensions of the surrounding frame structure (3), and a plurality of welding piece sacrificial structures (902) are arranged in an array along the inner perimeter direction and the outer perimeter direction of the welding piece body (901).

5. The method for hermetic packaging of a double-sided interconnected ceramic package SiP according to claim 4, characterized in that: The horizontal cross-section of the solder tab sacrificial structure (902) is in the shape of a semicircle, a rectangle or a triangle.

6. The method for hermetic packaging of a double-sided interconnected ceramic package SiP according to claim 3, characterized in that: The first soldering piece (8) is limited by the first limiting solder resist ring and includes: The first limiting solder resist ring limits the outer side of the first soldering piece (8); The second soldering piece (9) is limited by the second limiting solder resist ring and includes: The second limiting solder resist ring limits the inner side of the second soldering piece (9).

7. A double-sided interconnected ceramic package SiP hermetic packaging method according to claim 1 or 2, characterized in that: The method of producing a limiting solder resist layer (5) at the bottom end of the planar ceramic cover plate (2) comprises: A limiting solder resist layer (5) is screen-printed on the bottom end of the planar ceramic cover plate (2).

8. A double-sided interconnected ceramic package SiP hermetic packaging method according to claim 1 or 2, characterized in that: The solder layer limited by the limited position solder resist layer (5) pre-set at the bottom end of the planar ceramic cover plate (2) comprises: On a hot plate with an operating temperature lower than the melting point of the solder layer, the solder layer is placed on the bottom end of the flat ceramic cover plate (2), and pressure is applied to the solder layer to fix the solder layer on the flat ceramic cover plate (2).

9. A double-sided interconnected ceramic package SiP hermetic packaging method according to claim 1 or 2, characterized in that: The process of stacking the planar ceramic cover plate (2) and the three-dimensional ceramic base plate (1) relative to each other so that the frame structure (3) and the plurality of cylindrical structures (4) abut against the solder layer and then performing eutectic welding comprises: The planar ceramic cover plate (2) and the three-dimensional ceramic base plate (1) are stacked relative to each other in a welding fixture (10), and the welding fixture (10) is placed in a vacuum eutectic furnace so that the frame structure (3) and the plurality of cylindrical structures (4) on the three-dimensional ceramic base plate (1) are eutectic welded to the planar ceramic cover plate (2).

10. A double-sided interconnected ceramic package SiP hermetic packaging method according to claim 1 or 2, characterized in that: Circuit patterns and pads are provided at both ends of the planar ceramic cover plate (2) and the three-dimensional ceramic base plate (1).

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