Packaging structure and process

Abstract

The invention provides a packaging structure and process, the packaging structure comprises a substrate and a shell arranged on the substrate, the substrate is connected with the shell, a vacuum cavity is formed between the substrate and the shell through a vacuumizing part, the outer surface of the shell is provided with a sealing layer, and the sealing layer is sealed in the vacuumizing part; therefore, a low-thermal-stress, low-deformation and high-vacuum packaging environment is formed through packaging, high sensitivity, high precision and long-term stable work of the micro-electro-mechanical sensor chip are guaranteed, and packaging difficulty and cost are reduced as much as possible under the condition that high sensitivity, high precision and long-term stable work of the micro-electro-mechanical sensor chip are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging structures, and in particular to a packaging structure and process. Background Art

[0002] MEMS micro-electromechanical sensors such as accelerometers and gyroscopes are susceptible to external changes such as stress, strain, moisture corrosion and air damping, which seriously affect the performance and function of the device itself. Therefore, the chips of such devices need to work in a vacuum state because they need to operate in a vacuum environment.

[0003] In the prior art, for chips that are flip-chip soldered on a substrate, a large area of ​​coating resin material is directly covered on the back of the chip to form a packaging structure. Although the formation of the cavity is achieved to a certain extent, the large area of ​​coating resin material directly covers the back of the chip, which will produce great thermal stress on the chip itself. At the same time, because the film is a resin material that is water-absorbent and not completely airtight, the chip cannot work in a vacuum state. Therefore, this structure cannot meet the packaging requirements of micro-electromechanical sensors such as accelerometers and gyroscopes.

[0004] To this end, one solution is to form a packaging cavity on the chip, reserve a vent hole on the packaging cavity, and use the existing wafer bonding technology for packaging. Then the bonded assembly is placed in a high temperature, high vacuum environment, and the gas in the micro chamber is extracted through the reserved vent hole, so that the pressure of the bonding chamber is the same as the environment. Finally, other processes (such as hot pressing welding) are used to seal the reserved vent hole, so that the bonding chamber has a very high vacuum degree and good air tightness. For example, Druck uses glass tubes to vacuum package pressure sensors based on this principle. However, the vacuuming process requires the bonded assembly to be placed in a high temperature, high vacuum environment, and the vacuuming process environment is relatively high. In addition, the temperature of the hot pressing welding sealing vent hole is as high as 320°C. The high temperature packaging vent hole increases the difficulty of the packaging process, resulting in a high cost of the packaging structure, which limits its scope of use. Summary of the invention

[0005] In order to solve technical problems such as how to package to form a packaging environment with low thermal stress, low deformation and high vacuum, and how to reduce the difficulty and cost of the packaging process to form a packaging environment with low thermal stress, low deformation and high vacuum, the present application provides a packaging structure and process.

[0006] In a first aspect, the present application provides a packaging structure, including: a substrate;

[0007] A shell, wherein the shell cover is disposed on the substrate, and the shell and the substrate define a hollow cavity;

[0008] A vacuum pumping unit, which is disposed on the substrate and / or the housing and is used to extract gas from the hollow cavity;

[0009] The sealing layer, at least a portion of which seals the vacuum portion, so that the housing and the substrate define a vacuum cavity.

[0010] In a specific possible implementation manner, a plurality of welding parts are provided at intervals at the connection between the substrate and the shell, and a vacuum part is formed between every two adjacent welding parts; and / or, a welding part is provided at the connection between the substrate and the shell, and a vacuum part is provided on the welding part.

[0011] In a specific possible implementation manner, an anti-immersion element is provided on the shell, and the anti-immersion element and the vacuum pumping part form an anti-immersion structure to prevent the sealing material that generates the sealing layer from immersing into the vacuum cavity.

[0012] In a specific possible implementation manner, a flow guiding structure is provided on the inner end surface of the vacuuming portion to prevent the sealing material forming the sealing layer from being immersed in the vacuum cavity.

[0013] In a specific embodiment, the sealing layer seals the housing to the substrate.

[0014] In a specific possible implementation manner, an inner end surface of the vacuum pumping portion close to the substrate is a non-horizontal structure or a non-planar structure.

[0015] In a specific possible implementation scheme, chips and / or components are arranged on the base island of the substrate; wherein the chips and / or components are electrically connected to the substrate pads of the base island; the base island is located in the hollow cavity and has a gap with the outer shell.

[0016] In a specific implementation manner, the sealing material includes: epoxy resin and inorganic filler particles, and the weight proportion of the inorganic filler particles is greater than 55%.

[0017] In a specific embodiment, the particle size of the inorganic filler particles is 6 μm-20 μm.

[0018] In a second aspect, the present application provides a packaging process, comprising the following steps:

[0019] Providing a substrate, electrically connecting the chip, and / or, the components to the substrate pads of the substrate;

[0020] Providing a housing, wherein the housing is placed on top of the substrate and defines a hollow cavity with the substrate;

[0021] The gas in the hollow cavity is extracted by the vacuum extraction part;

[0022] The vacuum pumping part is sealed, and the housing and the substrate define a vacuum cavity.

[0023] In a specific embodiment, the vacuum part is sealed, and the process further comprises:

[0024] Providing a first sealing material, wherein the first sealing material forms a pre-seal in the vacuuming portion;

[0025] A second sealing material is provided, the second sealing material sealing the housing to the substrate to form a sealing layer.

[0026] In summary, the packaging structure and process provided by the present application have the following beneficial technical effects:

[0027] The outer surface of the shell is provided with a sealing layer. The method of forming the sealing layer outside the shell can not only achieve the effect of sealing the vacuum part, but also improve the stability of the entire packaging structure, and achieve the beneficial effect of strengthening the packaging structure. The sealing layer melts at a temperature of ≤100°C to seal the vacuum part, thereby reducing the temperature of vacuum melting and sealing, which not only reduces the packaging energy consumption, but also enables the packaging process to be widely used;

[0028] The shell is provided with an anti-immersion element, and the anti-immersion element is arranged corresponding to the vacuum pumping part. The vacuum pumping part is close to an inner end surface of the substrate and is a non-horizontal structure or a non-planar structure. The vacuum pumping part is provided with a flow guide. Selecting any of the above structures can not only ensure that the vacuum pumping part can be sealed by the sealing layer, but also reduce the probability of the sealing material dipping into the vacuum cavity, thereby improving the air tightness of the packaging structure. The sealing material forming the sealing layer is preferably an anti-immersion vacuum cavity sealing material. Further, the anti-immersion vacuum cavity sealing material is preferably a mixture of epoxy resin and inorganic filler particles. The compounding of epoxy resin and inorganic filler particles can further ensure that the vacuum pumping part can be sealed by the sealing layer while reducing the probability of the sealing material dipping into the vacuum cavity.

[0029] The packaging structure and process provided by the present application not only form a packaging environment with low thermal stress, low deformation and high vacuum, thereby ensuring the high sensitivity, high precision and long-term stable operation of the micro-electromechanical sensor chip, but also ensure that the micro-electromechanical sensor chip has high sensitivity, high precision and long-term stable operation while reducing the packaging difficulty and cost as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the packaging structure provided by the present invention (the vacuum pumping part is provided on the shell);

[0031] Figure 2: is a structural schematic diagram of the packaging structure provided by the present invention (the vacuum pumping part is provided on the shell, and a sealing layer is provided on the outer surface of the shell, and the sealing layer seals the vacuum pumping part);

[0032] Figure 3 It is a structural schematic diagram of the packaging structure provided by the present invention (the vacuum pumping part is arranged at the connection between the substrate and the shell);

[0033] Figure 4 It is a structural schematic diagram of the packaging structure provided by the present invention (the vacuum pumping part is arranged at the connection between the substrate and the shell, and the outer surface of the shell is provided with a sealing layer, and the sealing layer seals the vacuum pumping part);

[0034] Figure 5 It is a structural side view of the packaging structure provided by the present invention (the vacuum pumping part is arranged at the connection between the substrate and the shell, and the outer surface of the shell is provided with a sealing layer, which seals the vacuum pumping part);

[0035] Figure 6 It is a partial structural schematic diagram of the packaging structure provided by the present invention;

[0036] Figure numerals: 1-housing; 2-substrate; 3-vacuum part; 4-welding piece; 5-gold wire; 6-substrate pad; 7-sealing layer; 8-chip; 9-vacuum chamber; 10-anti-immersion element. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0038] Embodiment 1

[0039] like Figure 1-5 As shown, the present application provides a packaging structure, including: a substrate 2, a shell 1, a vacuum part 3 and a sealing layer 7; wherein the shell 1 is covered on the substrate 2, and the shell 1 and the substrate 2 define a hollow cavity; the vacuum part 3 is arranged on the substrate 2 and / or the shell 1, and is used to extract the gas from the hollow cavity; at least a portion of the sealing layer 7 seals the vacuum part 3, so that the shell 1 and the substrate 2 define a vacuum cavity 9.

[0040] In one embodiment, a substrate pad 6 is disposed on the substrate 2 , and a chip 8 and / or components are disposed on the substrate pad 6 .

[0041] In one specific embodiment, a plurality of welding parts 4 are provided at intervals at the connection between the substrate 2 and the outer shell 1, and a vacuum extraction part 3 is formed between every two adjacent welding parts 4; and / or, a welding part 4 is provided at the connection between the substrate 2 and the outer shell 1, and a vacuum extraction part 3 is provided on the welding part 4.

[0042] Specifically, a plurality of welding parts 4 are provided at intervals at the connection between the substrate 2 and the shell 1, and a vacuum part 3 is formed between every two adjacent welding parts 4, including: a welding material coating area and a welding material blank area are formed at the connection between the substrate 2 and the shell 1; a retaining wall is provided at the junction of the welding material coating area and the welding material blank area to ensure that the welding material will not overflow into the welding material blank area during the process of melting the welding material to generate the welding parts 4; wherein the height of the retaining wall is not higher than the height of the welding parts 4.

[0043] Furthermore, a welding part 4 is provided at the connection between the substrate 2 and the shell 1, and a process flow of a vacuum pumping part 3 is opened on the welding part 4, including: forming a welding material coating area at the connection between the substrate 2 and the shell 1; melting the welding material in the welding material coating area to form the welding part 4; and opening a vacuum pumping part 3 on the welding part 4 to remove the gas in the hollow cavity defined by the shell 1 and the substrate 2.

[0044] In one embodiment, an anti-immersion element 10 is provided on the housing 1, and the anti-immersion element 10 and the vacuum pump 3 form an anti-immersion structure to prevent the sealing material forming the sealing layer 7 from being immersed in the vacuum cavity 9. Figure 6 As shown, the vacuum part 3 is arranged on the substrate 2 to form a groove, and the anti-immersion element 10 is a convex block provided at the bottom of the housing 1 and adapted to the vacuum part 3, and the groove (vacuum part 3) and the convex block (anti-immersion element 10) form an anti-immersion structure; specifically, when the vacuum part 3 is sealed with a sealing material, the sealing material forming the sealing layer 7 flows along the side groove wall to the bottom of the groove, and the sealing material only needs to fill the gap between the bottom of the groove and the convex part of the convex block to achieve the sealing of the vacuum part 3. Based on the anti-immersion structure as described above, the probability of the sealing material immersing into the vacuum cavity 9 is reduced by reserving redundant space for the sealing material forming the sealing layer 7, thereby reducing the probability of the chip 8 and / or components being contaminated.

[0045] In one embodiment, the inner end surface of the vacuuming portion 3 is provided with a guide structure to prevent the sealing material for forming the sealing layer 7 from being immersed in the vacuum cavity 9. Specifically, the line shape of the inner end surface of the vacuuming portion 3 is set to a folded line shape, that is, the vacuuming portion 3 forms a folded line vacuuming channel, and the probability of the sealing material for forming the sealing layer 7 being immersed in the vacuum cavity 9 is reduced by increasing the immersion route of the sealing material for forming the sealing layer 7 to be immersed in the vacuum cavity 9, thereby reducing the probability of the chip 8 and / or components being contaminated.

[0046] In one embodiment, the sealing layer 7 seals the housing 1 to the substrate 2, which ensures that the vacuum part 3 is completely sealed and the vacuum cavity 9 is airtight, while also facilitating improving the stability of the entire packaging structure.

[0047] In one embodiment, a chip 8 and / or components are arranged on the base island of the substrate 2; wherein the chip 8 and / or components are electrically connected to the substrate pad 6 of the base island; the base island is located in the hollow cavity and has a gap with the housing 1. A gap is set between the base island for arranging the chip 8 and / or components and the housing 1 to reserve redundant space for the sealing material forming the sealing layer 7, thereby reducing and preventing the sealing material from contaminating the chip 8 and / or components.

[0048] In one embodiment, the sealing material comprises: epoxy resin and inorganic filler particles, the weight proportion of the inorganic filler particles is greater than 55%, and the particle size of the inorganic filler particles is 6 μm-20 μm.

[0049] Embodiment 2

[0050] This embodiment provides a packaging process, which includes:

[0051] Step S1, providing a substrate 2, and electrically connecting a chip 8 and / or components to a substrate pad 6 of the substrate 2;

[0052] Step S2, providing a housing 1, and placing the housing 1 on the top of the substrate 2 to define a hollow cavity on the substrate 2;

[0053] Step S3, removing the gas in the hollow cavity through the vacuum pumping part 3;

[0054] Step S4 , sealing the vacuum part 3 , and the housing 1 and the substrate 2 define a vacuum chamber 9 .

[0055] In one embodiment, the process further comprises the following steps: sealing the vacuum part 3, the process further comprises:

[0056] Providing a first sealing material, wherein the first sealing material forms a pre-seal in the vacuuming portion 3;

[0057] A second sealing material is provided, and the second sealing material seals the housing 1 to the substrate 2 to form a sealing layer 7 .

[0058] Embodiment 3

[0059] The present embodiment provides a packaging structure, which includes: a substrate 2 and a shell 1 arranged on the substrate 2, wherein a chip 8 is connected to the substrate 2 by flip-chip connection or wire bonding, and preferably, a plurality of substrate 2 pads 6 are arranged on the substrate 2, and the chip 8 is bonded to the substrate 2 pads 6 by gold wires 5, and the substrate 2 is preferably a ceramic substrate 2, which can reduce the thermal stress of the chip 8 package, and the shell 1 is arranged on the chip 8 and connected with the substrate 2 to define a hollow cavity, and in order to further reduce the thermal stress of the chip 8 package, preferably, the chip 8 is only in contact with the substrate 2, and specifically, the chip 8 is arranged in the hollow cavity, and one end face of the chip 8 is connected to the substrate 2, a first gap is formed between the other end face of the chip 8 and the shell 1, a second gap is formed between one side face of the chip 8 and the shell 1, and a third gap is formed between the other side face of the chip 8 and the shell 1;

[0060] The vacuum part 3 is provided on the shell 1, and a sealing layer 7 is provided on the outer surface of the shell 1. The sealing layer 7 is sealed in the vacuum part 3. The sealing layer 7 on the outer surface of the shell 1 can not only seal the vacuum part 3, but also improve the stability of the entire packaging structure, thereby achieving the beneficial effect of strengthening the packaging structure. The vacuum part 3 is provided on the shell 1, and the air in the hollow cavity is vacuumed by the vacuum part 3 to form a vacuum cavity 9. The melting point of the sealing material forming the sealing layer 7 is not greater than 100°C. Therefore, the present application adopts low-temperature (≤100°C) vacuuming to melt the sealing material to form the sealing layer 7 to seal the vacuum part 3, which not only reduces the temperature of melting the sealed vacuum part 3, but also reduces the packaging energy consumption, and makes the packaging structure widely used;

[0061] Preferably, the vacuum pumping part 3 is opened on the outer shell 1 near one end of the substrate 2. Because if the sealing material forming the sealing layer 7 has fluidity, when the vacuum pumping part 3 is opened on the top of the outer shell 1, the sealing material forming the sealing layer 7 will drip into the vacuum cavity 9 due to its fluidity and inertia, which will increase the probability of contamination of the chip 8 and / or components. Therefore, it is best not to open the vacuum pumping part 3 on the top of the outer shell 1.

[0062] Preferably, the vacuuming part 3 is opened on the housing 1 close to one end of the substrate 2 and as far away from the chip 8 as possible to reduce or prevent the probability of the sealing material entering the vacuum chamber 9 and contaminating the chip 8 .

[0063] Preferably, a guide member (not shown) is provided at the vacuum pumping part 3, and the vacuum pumping part 3 is opened on the outer shell 1 away from one end of the substrate 2. No matter where the vacuum pumping part 3 is opened in the outer shell 1, the sealing material will be immersed in the vacuum cavity 9. Therefore, a guide member (not shown) can be provided at the vacuum pumping part 3 to reduce or prevent the sealing material from being immersed in the vacuum cavity 9. The guide member (not shown) is preferably an annular structure.

[0064] The vacuuming part 3 is preferably a narrow square hole, the length of which is less than 0.3 mm, and the width of which is less than 0.1 mm. In order to facilitate the processing of the shell 1, the vacuuming part 3 can also be a round hole, such as one or more holes of 0.1 mm, and the number of holes is proportional to the size of the vacuum cavity 9.

[0065] The packaging structure described in this embodiment has the following beneficial effects: since the material of the substrate 2 is a ceramic material, and the material of the shell 1 is a metal material, the substrate 2 is connected to the shell 1 and a vacuum chamber 9 is formed between the substrate 2 and the shell 1 through the vacuum pump 3, a chip 8 is arranged in the vacuum chamber 9, and one end face of the chip 8 is connected to the substrate 2, a first gap is formed between the other end face of the chip 8 and the shell 1, a second gap is formed between one side face of the chip 8 and the shell 1, and a third gap is formed between the other side face of the chip 8 and the shell 1, and the chip 8 is only in contact with the substrate 2 made of ceramic material, which not only reduces the packaging of the chip 8, but also reduces the packaging of the chip 8. Thermal stress is reduced, and the cost of chip 8 packaging is reduced; since the sealing layer 7 covers the outer surface of the shell 1 during the chip 8 packaging process, it not only strengthens the packaging structure and reduces the possibility of deformation of the packaging structure, but also improves the stability of the entire packaging structure; the substrate 2 is connected to the shell 1 to form a hollow cavity, and the air in the hollow cavity is evacuated by the vacuum pumping part 3, so that a vacuum cavity 9 is formed between the substrate 2 and the shell 1. The present application does not need to place the bonded assembly sheet in a high temperature and high vacuum environment for vacuuming, which reduces the difficulty of the packaging process and the packaging cost. The packaging forms a packaging environment with low thermal stress, low deformation and high vacuum, which ensures the stable operation of the micro-electromechanical sensors.

[0066] Embodiment 4

[0067] The present application provides a packaging process for a packaging structure, comprising the following steps:

[0068] Soldering the chip 8 onto the substrate 2;

[0069] The housing 1 is connected to the substrate 2 by reflow soldering of a soldering material to form a hollow cavity, wherein the soldering material is preferably a metal material, and the metal material is preferably solder paste;

[0070] When the vacuum part 3 is opened on the housing 1, the air in the hollow cavity is evacuated by the vacuum part 3 to form a vacuum cavity 9, and the vacuum part 3 is pre-sealed by a pre-sealing material to prevent external air from entering the vacuum cavity 9. The pre-sealing material is preferably a material such as glue;

[0071] A sealing layer 7 is formed outside the housing 1 to seal the vacuum part 3. The sealing layer 7 is preferably formed of a sealing material having a melting point of not more than 100°C. The vacuum part 3 is sealed by vacuum melting at a low temperature (≤100°C), and the temperature of melting the sealing material and sealing the vacuum part 3 is reduced, which not only reduces the packaging energy consumption, but also enables the packaging process to be widely used.

[0072] Preferably, the sealing material forming the sealing layer 7 includes: an anti-immersion vacuum cavity sealing material, and the anti-immersion vacuum cavity sealing material includes: epoxy resin and inorganic filler particles, the weight proportion of the inorganic filler particles is greater than 55%, and is densely distributed in a narrow particle size. Preferably, the weight proportion of the inorganic filler particles is 55%, 56%, 57%, 58%, 59%, 60%, which will not be listed here due to space limitations. The anti-immersion vacuum cavity sealing material is preferably a mixture of epoxy resin and inorganic filler particles, which can further ensure that the vacuum part 3 can be sealed by the sealing layer 7 while reducing the probability of the sealing layer 7 being immersed in the vacuum cavity 9;

[0073] The particle size of the inorganic filler particles is preferably 6 μm-20 μm; preferably, the particle size of the inorganic filler particles is 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, which will not be listed here due to space limitations.

[0074] The material of the shell 1 is preferably metal, which reduces the cost of using ceramic as the material of the shell 1 and reduces the cost of the packaging structure;

[0075] The method of forming a sealing layer 7 outside the housing 1 with an anti-immersion vacuum cavity sealing material can not only seal the vacuum part 3, but also improve the stability of the entire packaging structure, thereby achieving the beneficial effect of strengthening the packaging structure.

[0076] Embodiment 5

[0077] The present application provides a packaging process for a packaging structure, comprising the following steps:

[0078] Soldering the chip 8 onto the substrate 2;

[0079] The housing 1 is connected to the substrate 2 by reflow soldering of a soldering material to form a hollow cavity, and the soldering material is welded at intervals at the connection between the substrate 2 and the housing 1 to form a soldering part 4, and a vacuum part 3 is formed between every two adjacent soldering materials, and the soldering material is preferably a metal material, and the metal material is preferably solder paste;

[0080] After the air in the hollow cavity is evacuated by the evacuation part 3, the evacuation part 3 is pre-sealed by a pre-sealing material to prevent external air from entering the vacuum cavity 9. The pre-sealing material is preferably a material such as glue;

[0081] A sealing layer 7 is formed outside the housing 1 to seal the vacuum section 3 .

[0082] Preferably, the sealing material forming the sealing layer 7 includes: an anti-immersion vacuum cavity sealing material, the anti-immersion vacuum cavity sealing material includes: epoxy resin and inorganic filler particles, the weight proportion of the inorganic filler particles is greater than 55%, and is densely distributed in a narrow particle size, preferably, the weight proportion of the inorganic filler particles is 55%, 56%, 57%, 58%, 59%, 60%, which are not listed here due to space limitations. The anti-immersion vacuum cavity sealing material is preferably a mixture of epoxy resin and inorganic filler particles, which can further ensure that the vacuum part 3 can be sealed by the sealing layer 7 while reducing the probability of the sealing material immersing into the vacuum cavity 9;

[0083] The particle size of the inorganic filler particles is preferably 6 μm-20 μm; preferably, the particle size of the inorganic filler particles is 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, which will not be listed here due to space limitations.

[0084] The material of the shell 1 is preferably metal, which reduces the cost of using ceramic as the material of the shell 1 and reduces the cost of the packaging structure;

[0085] The method of forming a sealing layer 7 outside the housing 1 with an anti-immersion vacuum cavity sealing material can not only seal the vacuum part 3, but also improve the stability of the entire packaging structure, thereby achieving the beneficial effect of strengthening the packaging structure.

[0086] The above is a detailed introduction to a packaging structure and process provided by the present application. The principles and implementation methods of the present application are described in detail using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A packaging structure, It is characterized in that include: substrate; A shell, wherein the shell cover is disposed on the substrate, and the shell and the substrate define a hollow cavity; A vacuum pumping unit, which is disposed on the substrate and / or the housing and is used to extract gas from the hollow cavity; The sealing layer, at least a portion of which seals the vacuum portion, so that the housing and the substrate define a vacuum cavity.

2. The packaging structure according to claim 1, It is characterized in that A plurality of welding parts are arranged at intervals at the connection between the substrate and the shell, and a vacuum part is formed between every two adjacent welding parts; And / or, a welding piece is provided at the connection between the substrate and the shell, and a vacuum pumping part is provided on the welding piece.

3. The packaging structure according to claim 2, It is characterized in that The shell is provided with an anti-immersion element, and the anti-immersion element and the vacuum pumping part form an anti-immersion structure to prevent the sealing material that forms the sealing layer from immersing into the vacuum cavity.

4. The packaging structure according to claim 2 or 3, It is characterized in that The inner end surface of the vacuuming part is provided with a flow guiding structure to prevent the sealing material forming the sealing layer from being immersed in the vacuum cavity.

5. The packaging structure according to claim 4, It is characterized in that The sealing material comprises: epoxy resin and inorganic filler particles, and the weight proportion of the inorganic filler particles is greater than 55%.

6. The packaging structure according to claim 5, It is characterized in that The particle size of the inorganic filler particles is 6 μm-20 μm.

7. The packaging structure according to claim 6, It is characterized in that The sealing layer seals the housing to the substrate.

8. The packaging structure according to claim 7, It is characterized in that A chip and / or a component is arranged on the base island of the substrate; wherein the chip and / or the component is electrically connected to the substrate pad of the base island; The base island is located in the hollow cavity and has a gap with the shell.

9. A packaging process, It is characterized in that The method is used to form a packaging structure as claimed in any one of claims 1 to 7; comprising the following steps: Providing a substrate, electrically connecting the chip, and / or, the components to the substrate pads of the substrate; Providing a housing, covering the housing on the top of the substrate, and defining a hollow cavity with the substrate; The gas in the hollow cavity is extracted by the vacuum extraction part; The vacuum pumping part is sealed, and the housing and the substrate define a vacuum cavity.

10. The packaging process according to claim 9, It is characterized in that The following steps are involved: The vacuuming portion is sealed, and the process further comprises: Providing a first sealing material, wherein the first sealing material forms a pre-seal in the vacuuming portion; A second sealing material is provided, the second sealing material sealing the housing to the substrate to form a sealing layer.

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