Three-dimensional ceramic packaging structure

Abstract

The utility model discloses a three-dimensional ceramic packaging structure, which comprises a ceramic shell and a chip set, the ceramic shell is provided with a circle of cofferdam which is vertically upward, a core cavity is formed in the ceramic shell, the chip set comprises a horizontal chip set and a vertical chip set, the horizontal chip set is attached to the bottom of the core cavity and is horizontally arranged, and the vertical chip set is attached to the bottom of the core cavity. The vertical chip set is attached to an L-shaped ceramic substrate and is electrically connected with the L-shaped ceramic substrate, the substrate is attached to the inner wall of the cofferdam to enable the vertical chip set to be vertically arranged, the L-shaped ceramic substrate comprises a horizontal part and a vertical part, the horizontal part is attached to the inner wall of the cofferdam, the vertical part is attached to the bottom of the core cavity, and the vertical part is electrically connected with the ceramic shell through a bonding wire. And a sealing cover plate is arranged at the top of the ceramic shell and covers the core cavity. Bare core packaging is adopted in the packaging circuit, the substrate in the vertical direction is of an L-shaped structure, supporting in two directions is achieved, the problem that the precision of the circuit is affected by large deformation and the like is avoided, and the requirements for high precision, reliability and air tightness are met.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging technology, and more specifically to a three-dimensional ceramic packaging structure. Background Technology

[0002] In common ceramic packages, internal components such as chips and resistors / capacitors are typically mounted in the same orientation inside the casing. However, for sensor chips, such as inertial sensors, unidirectional mounting only allows sensing information in that single direction. In practical applications, to accurately capture X, Y, and Z-axis directional information, corresponding sensing chips need to be mounted in each of the three directions. Furthermore, to achieve sensing in both forward and reverse X, Y, and Z directions, two sets of circuitry are required in each direction, totaling six sets of circuitry across the three directions. This significantly complicates circuit application and assembly, and also increases assembly space requirements.

[0003] Ceramic packaging is widely used in high-reliability applications because it allows for hermetic sealing. Furthermore, the cavity structure of ceramic packaging is beneficial for achieving optimal sensor performance. Therefore, by using ceramic packaging to implement X, Y, and Z-axis sensors within a single ceramic shell, a single circuit can achieve sensing in different directions along all three axes, greatly simplifying circuit applications.

[0004] Common ceramic three-dimensional encapsulation structures, such as Figure 1 As shown, a sensor chip 103 is mounted on the bottom ceramic substrate 101 for Z-direction sensing; while X (or Y) direction sensing is achieved by the sensor chip 103 mounted on the ceramic substrate 102. The vertical ceramic substrate 102 and the horizontal ceramic substrate 101 are usually soldered together with solder 104 to provide electrical connection and structural fixation. The main disadvantages of this packaging structure are: 1) Due to the relative difficulty of vertical assembly, the sensor chip 103 often uses pre-packaged finished circuits, which means that the bare chip has already been packaged once, and this is equivalent to a second packaging, which increases the circuit cycle and cost; 2) The interconnection between the substrate 102 and the substrate 101 is achieved by solder 104. The solder needs to achieve electrical connection and also serve as a major structural component. When the substrate 102 is subjected to repeated stress in different directions, there is not enough support in the two directions perpendicular to the substrate 101, which can easily lead to connection failure; and when the substrate 102 in the vertical direction is supported on only one side, the sensing accuracy of the circuit may be affected in the opposite direction; 3) This structure is also not easy to achieve hermetic packaging. Utility Model Content

[0005] To address the aforementioned issues, this invention provides a three-dimensional ceramic packaging structure. It utilizes a bare chip to achieve three-dimensional ceramic packaging, and the vertical substrate employs an L-shaped structure to provide support in both directions, thus avoiding large deformations that could affect circuit accuracy and meeting requirements for high precision, reliability, and airtightness.

[0006] According to one aspect of the present invention, a three-dimensional ceramic packaging structure is provided, including a ceramic shell and a chipset encapsulated within the ceramic shell;

[0007] The ceramic outer shell has a vertically upward-facing surrounding dam, and the interior of the surrounding dam forms a core cavity;

[0008] The chipset includes a horizontal chipset and a vertical chipset. The horizontal chipset is mounted on the bottom of the cavity and is arranged horizontally. The horizontal chipset is electrically connected to the ceramic shell through bonding wires. The vertical chipset is mounted on a substrate and is electrically connected. The substrate is mounted on the inner wall of the dam so that the vertical chipset is arranged vertically and is close to the bottom of the cavity. The substrate is electrically connected to the ceramic shell through bonding wires.

[0009] The top of the ceramic shell is provided with a sealing cover plate, which covers the core cavity.

[0010] Therefore, the horizontal and vertical chipsets are mounted inside the core cavity of the ceramic housing, using bare-die packaging, which can shorten the product cycle and save costs; the top of the ceramic housing with a dam is equipped with a sealing cover to ensure the airtightness of the package, making the packaged product suitable for high-reliability application scenarios such as high humidity and high temperature; and the vertical substrate is connected to the ceramic housing by wire bonding, with the bonding wires playing the role of electrical connection, rather than relying on structural connectors, which can significantly improve the reliability of the connection.

[0011] In some embodiments, the substrate is an L-shaped ceramic substrate, which includes a horizontal portion and a vertical portion. The horizontal portion is mounted on the inner wall of the containment dam, and the vertical portion is mounted on the bottom of the core cavity. The vertical chipset is mounted on the horizontal portion and forms an electrical connection, while the vertical portion forms an electrical connection with the ceramic shell. Thus, by using an L-shaped ceramic substrate in the vertical direction, the substrate is supported in both directions when subjected to stress or acceleration in different directions. That is, the back of the L-shaped ceramic substrate is supported by the containment dam, and the front is supported by the bottom of the L-shaped ceramic substrate, avoiding problems such as large deformation that could affect the accuracy of the circuit.

[0012] In some implementations, the substrate is composed of multiple layers of stacked ceramics. This can be achieved using conventional high-temperature co-fired (HTCC) and low-temperature co-fired (LTCC) processes, which are conventional and existing technologies that can be implemented with low process risk.

[0013] In some implementations, the height of the vertical portion is at least 0.2 mm higher than the height of the vertical chipset after it is mounted on the horizontal portion. This satisfies the bonding process requirements between the substrate and the ceramic housing.

[0014] In some embodiments, the vertical portion of the substrate has pads for bonding the bonding wires, and the surface flatness of the pads in the vertical portion is ≤30μm. This ensures the surface flatness of the pads in the vertical portion to meet subsequent bonding requirements.

[0015] In some embodiments, the vertical chipset mounted on the substrate is provided in one, two, three, or four groups, each respectively mounted on the inner walls of the surrounding dam. Thus, depending on the actual product requirements, up to four L-shaped ceramic substrates can be mounted on the four sides of the ceramic shell's surrounding dam, allowing for a more flexible design of the chipset inside the product.

[0016] In some implementations, a welding frame is provided above the cofferdam, and a sealing cover is installed on the welding frame. Thus, the welding frame facilitates the installation of the sealing cover to seal the entire circuit.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: The three-dimensional ceramic packaging structure provided by this utility model adopts a ceramic shell with a core cavity. The internal packaging circuit adopts bare core packaging, and the chip group in the vertical direction is pre-installed on the L-shaped ceramic substrate. Then, the L-shaped ceramic substrate with the chip group is mounted inside the ceramic shell. One side of the L-shaped ceramic substrate is closely attached to the dam, and the adjacent side is closely attached to the bottom of the core cavity, forming support in both directions. In this way, when the product is subjected to stress or acceleration in different directions, it can avoid large deformation and other problems, ensuring that the accuracy of the circuit is not affected. The ceramic shell has a welding frame to facilitate the installation of the sealing cover. This three-dimensional ceramic packaging structure can shorten the product cycle, save costs, and has good airtightness, which can adapt to high reliability application scenarios and meet the current market demand for high precision, reliability, and airtightness. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a ceramic packaging structure in the prior art;

[0019] Figure 2 This is a schematic diagram of one embodiment of a three-dimensional ceramic packaging structure according to this utility model;

[0020] Figure 3 This is a schematic diagram of a vertically mounted chipset on a substrate, where 3A is the front view, 3B is the top view, and 3C is the side view.

[0021] Figure 4 This is a schematic diagram of the substrate structure. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments.

[0023] like Figure 2 and 3 As shown, a three-dimensional ceramic packaging structure according to one embodiment of the present invention includes a ceramic shell 1, a chipset encapsulated in the ceramic shell 1, and a sealing cover plate 5 installed on the top of the ceramic shell 1.

[0024] The ceramic shell 1 is a cuboid in shape. The ceramic shell 1 has a bottom surface and a vertically upward-facing surrounding dam 11 around its perimeter. The interior of the surrounding dam 11 forms a core cavity 12.

[0025] The chipset includes a horizontal chipset 2 and a vertical chipset 3. The horizontal chipset 2 is mounted to the bottom of the cavity 12 by adhesive or soldering. The horizontal chipset 2 is horizontally positioned, and its pads are electrically connected to the ceramic housing 1 by bonding wires. The vertical chipset 3 is mounted on a substrate 4, and the vertical chipset 3 is electrically connected to the substrate 4. The substrate 4 is mounted on the inner wall of the containment dam 11, and the vertical chipset 3 is vertically positioned. After mounting, the bottom of the substrate 4 is in close contact with the bottom of the cavity 12, and the substrate 4 is electrically connected to the ceramic housing 1 by bonding wires.

[0026] The ceramic housing 1 has a metal welding frame 13 above the cofferdam 11. The sealing cover 5 is installed on the welding frame 13. After the sealing cover 5 is installed, it covers the core cavity 12, thus sealing the entire circuit.

[0027] In this embodiment, as Figure 3 and 4 As shown, substrate 4 is an L-shaped ceramic substrate, which includes a horizontal portion 41 and a vertical portion 42. Substrate 4 is composed of multiple layers of ceramic stacks and can be achieved through conventional high-temperature co-firing (HTCC) and low-temperature co-firing (LTCC) processes. These processes are conventional and existing, and can be implemented based on existing technology, resulting in low process risk. The vertical chipset 3 is attached to the horizontal portion 41 with adhesive or solder to form an electrical connection, and then the L-shaped ceramic substrate 4 is attached. The horizontal portion 41 is bonded to the inner wall of the dam 11 with adhesive 6, and the vertical portion 42 is bonded to the bottom of the core cavity 12 with adhesive 6. The vertical portion 42 is electrically connected to the ceramic shell 1 by wire bonding with bonding wire 7. In this way, substrate 4 in the vertical direction uses an L-shaped ceramic substrate, which provides support in both directions when subjected to stress or acceleration in different directions. That is, the back of the L-shaped ceramic substrate is supported by the dam 11, and the front is supported by the bottom of the L-shaped ceramic substrate, avoiding large deformation and other problems that may affect the accuracy of the circuit.

[0028] To meet the bonding process requirements between the substrate 4 and the ceramic shell 1, the height of the vertical portion 42 of the L-shaped ceramic substrate must be at least 0.2 mm higher (H) than the height of the vertical chip assembly 3 after it is mounted on the horizontal portion 41. Furthermore, the surface flatness of the pads 421 on the vertical portion 42 of the substrate 4, i.e., the pads 421 used for bonding wires, is ≤30 μm. The surface pads 411 on the horizontal portion 41 of the substrate 4 have a conventional structure.

[0029] The number of vertical chip groups 3 mounted on the substrate 4 is set according to the actual product design requirements, and can be one, two, three, or four groups. These vertical chip groups 3 are all mounted on the substrate 4 and then respectively mounted on the four inner walls of the surrounding dam 11. There can be up to four L-shaped ceramic substrates with vertical chip groups 3 mounted on them, which are respectively mounted on the four sides of the surrounding dam 11 of the ceramic shell 1, making the design of the internal chip group of the product quite flexible.

[0030] The overall packaging sequence of the three-dimensional ceramic packaging structure is as follows: (1) First, the horizontal chip group 2 is electrically connected to the ceramic shell 1 by welding with glue or solder, and the vertical chip group 3 is electrically connected to the L-shaped ceramic substrate by welding with glue or solder. These assembly connections are completed separately. When assembling the vertical chip group 3 and the L-shaped ceramic substrate, the L-shaped ceramic substrate needs to be placed horizontally. The vertical chip group 3 is installed on the horizontal part 41 of the substrate 4. The surface of the horizontal part 41 also has bonding pads 411 for electrical connection between the vertical chip group 3 and the substrate 4. (2) The L-shaped ceramic substrate with the vertical chip group 3 assembled is glued and fixed to the inside of the ceramic shell 1 by glue 6. In addition to covering the bottom surface of the vertical part 42 of the L-shaped ceramic substrate, the glue 6 also needs to cover a certain amount on the back of the adjacent horizontal part 41 so that the two sides of the L-shaped ceramic substrate are fixed to the ceramic shell as a whole. (3) The vertical part 42 of the L-shaped ceramic substrate 4 is connected to the ceramic shell 1 by bonding wire 7 to form a vertical electrical connection between the substrate 4 and the ceramic shell 1. (4) Install the sealing cover plate 5 onto the welding frame 13 to seal the entire circuit.

[0031] In this embodiment, the vertical substrate 4 and the ceramic shell 1 are connected by wire bonding. The bonding wire 7 serves as an electrical connection instead of relying on structural connectors, which can significantly improve the reliability of the connection.

[0032] The three-dimensional ceramic packaging structure provided by this utility model adopts a ceramic shell 1 with a core cavity 12. The internal packaging circuit uses bare-core packaging, and the vertically mounted chipset is pre-installed on an L-shaped ceramic substrate 4. Then, the L-shaped ceramic substrate 4 with the chipset is mounted inside the ceramic shell 1. One side of the L-shaped ceramic substrate 4 is tightly attached to the cofferdam 11, and the adjacent side is tightly attached to the bottom of the core cavity 12, forming support in both directions. In this way, when the product is subjected to stress or acceleration in different directions, it can avoid large deformation and other problems, ensuring that the accuracy of the circuit is not affected. The ceramic shell 1 has a solder frame 13 to facilitate the installation of the sealing cover 5. This three-dimensional ceramic packaging structure can shorten the product cycle, save costs, and has good airtightness, making it suitable for high-reliability applications, such as high-humidity and high-temperature applications, meeting the current market's requirements for high precision, reliability, and airtightness.

[0033] The above descriptions are merely some embodiments of this utility model. It should be noted that those skilled in the art can make other modifications and improvements without departing from the inventive concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A three-dimensional ceramic packaging structure, comprising a ceramic shell (1) and a chipset encapsulated within the ceramic shell (1), characterized in that: The ceramic shell (1) has a vertically upward-facing circumferential dam (11), and the interior of the dam (11) forms a core cavity (12); The chipset includes a horizontal chipset (2) and a vertical chipset (3). The horizontal chipset (2) is mounted on the bottom of the cavity (12) and is arranged horizontally. The horizontal chipset (2) is electrically connected to the ceramic shell (1) through bonding wires. The vertical chipset (3) is mounted on a substrate (4) and forms an electrical connection. The substrate (4) is mounted on the inner wall of the dam (11) so that the vertical chipset (3) is arranged vertically. The substrate (4) is close to the bottom of the cavity (12). The substrate (4) is electrically connected to the ceramic shell (1) through bonding wires. The top of the ceramic shell (1) is provided with a sealing cover plate (5), which covers the core cavity (12).

2. The three-dimensional ceramic packaging structure according to claim 1, characterized in that, The substrate (4) is an L-shaped ceramic substrate, which includes a horizontal portion (41) and a vertical portion (42). The horizontal portion (41) is attached to the inner wall of the dam (11), and the vertical portion (42) is attached to the bottom of the core cavity (12). The vertical chip group (3) is attached to the horizontal portion (41) and forms an electrical connection. The vertical portion (42) forms an electrical connection with the ceramic shell (1).

3. The three-dimensional ceramic packaging structure according to claim 2, characterized in that, The substrate (4) is made of multiple layers of ceramic stacked together.

4. The three-dimensional ceramic packaging structure according to claim 3, characterized in that, The height of the vertical portion (42) is at least 0.2 mm higher than the height of the vertical chip assembly (3) after it is mounted on the horizontal portion (41).

5. The three-dimensional ceramic packaging structure according to claim 4, characterized in that, The vertical portion (42) of the substrate (4) has a pad (421) for bonding the bonding wire, and the surface flatness of the pad (421) of the vertical portion (42) is ≤30μm.

6. The three-dimensional ceramic encapsulation structure according to any one of claims 1 to 5, characterized in that, The vertical chip group (3) mounted on the substrate (4) has one, two, three or four groups, and each group is mounted on the inner wall of the surrounding dike (11).

7. The three-dimensional ceramic packaging structure according to claim 6, characterized in that, A welding frame (13) is provided above the cofferdam (11), and the sealing cover plate (5) is installed on the welding frame (13).

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