Packaging method of semiconductor substrate, packaging substrate and packaging control method

Abstract

The invention provides a semiconductor substrate packaging method, a packaging substrate and a packaging control method.The semiconductor substrate is provided with a first cavity structure, and the first cavity structure is communicated with the outside of the semiconductor substrate through at least one first potting hole. The packaging method comprises the following steps: S1, transferring a first container containing liquid metal and a semiconductor substrate into a closed container; and S2, after the pressure intensity in the closed container is reduced to negative pressure, the closed container communicates with the exterior of the closed container, so that the first cavity structure is filled with the liquid metal through the first filling and sealing hole. According to the invention, the technical problem that in the prior art, liquid metal cannot be effectively encapsulated into a tiny packaging substrate is solved.

Description

Technical Field

[0001] The present invention relates to the field of advanced semiconductor packaging technology, and in particular to a packaging method for a semiconductor substrate, a packaging substrate and a packaging control method. Background Art

[0002] In order to meet the heat dissipation needs of chips, the industry has mentioned the concept of near-junction heat dissipation, which is to miniaturize various heat dissipation structures and embed them in the electronic chip packaging structure, and use the embedded heat dissipation structure to bring the liquid cooling medium close to the heating grid area of ​​the electronic chip (with a spacing of less than 100μm) to achieve precise control of the junction temperature. According to whether the embedded liquid cooling technology requires external energy to drive the cooling medium, it can be divided into two forms: active and passive. Among them, active embedded liquid cooling requires external non-thermal physical effect power (such as mechanical force, electromagnetic force, etc.) to provide kinetic energy to drive the liquid cooling medium to circulate inside and outside the embedded cavity; the passive embedded liquid cooling method uses the thermal physical effects of the liquid cooling medium (such as thermal slip, phase change, capillary condensation, etc.) in a closed cavity to effectively suppress the heat accumulation caused by local high heat flux density. Compared with the complex external circulation pump and valve system that is indispensable for the active embedded liquid cooling structure, a satisfactory uniform temperature heat dissipation effect (±5°C) can be achieved by integrating the passive embedded liquid cooling structure in the substrate, and there is no need to consider the vertical interconnection of the flow paths between the substrate layers in 2.5D / 3D packaging.

[0003] In highly integrated electronic chip packaging, further improving passive heat dissipation capabilities faces challenges due to space limitations. To address this issue, liquid metal is considered to be an ideal heat dissipation material due to its high thermal conductivity, high boiling point, low melting point, low thermal expansion coefficient, and anti-magnetic properties. This allows liquid metal to withstand extreme temperature changes during packaging and operation while maintaining the performance of electronic devices, such as gallium-based alloys. Therefore, the solution proposed in the prior art is to embed liquid metal in the packaging substrate. For example, the current potting process for the existing embedded liquid metal TSV adapter board is mainly in a nitrogen atmosphere. The gallium-based liquid metal above the melting point is poured into the embedded cavity of the TSV adapter board by heating the Teflon syringe with a customized silicone heating belt and combining it with a programmable heating array tray. Figure 1 The method shown is to use a heated Teflon syringe to inject through the potting hole in a closed glove box filled with nitrogen. Figure 1 The process method of syringe filling is very poor when the adapter plate with a narrow cavity height (100 microns or even lower) is filled through the filling hole. The main reasons are as follows:

[0004] 1. Due to the large surface tension of gallium-based liquid metal, when the cavity height of the adapter plate is very low, the force of the syringe is far from enough to fill the liquid metal into the inside of the adapter plate, so that the liquid metal can only exist near the filling hole.

[0005] 2. The needle tube of the Teflon syringe is relatively long, much longer than the height of the adapter plate. When the syringe needle enters the potting hole, it can easily reach the bottom of the adapter plate, thereby blocking the potting hole and affecting the potting effect.

[0006] In summary, the existing potting process can only be used for liquid potting with relatively small surface tension for adapter plates with relatively high cavity height. If the cavity height is very low (such as 100 microns or even lower) and the liquid metal with relatively large surface tension is potted, the potting effect of this method is very poor, and the liquid metal can only be near the potting hole and cannot be potted in at all. However, it is usually impossible to design a TSV adapter plate with a very thick cavity height. Under the condition that gallium-based liquid metal with relatively large surface tension gradually becomes the mainstream thermal management material, this method is difficult to meet the requirements of existing processes.

[0007] Therefore, there is an urgent need for a process that can effectively fill liquid metal into a tiny packaging substrate. Summary of the invention

[0008] The main purpose of the present invention is to provide a semiconductor substrate packaging method, a packaging substrate and a packaging control method to solve the technical problem in the prior art that liquid metal cannot be effectively filled into a tiny packaging substrate.

[0009] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a packaging method for a semiconductor substrate is provided, wherein the semiconductor substrate has a first cavity structure, and the first cavity structure is connected to the outside of the semiconductor substrate through at least one first potting hole, and the packaging method comprises the following steps: S1: transferring a first container containing liquid metal and a semiconductor substrate to a sealed container; S2: after reducing the pressure in the sealed container to a negative pressure, connecting the sealed container to the outside of the sealed container, so as to fill the liquid metal into the first cavity structure through the first potting hole.

[0010] Optionally, the packaging method further includes: placing the liquid metal in a second container; placing the second container on a heating device; and transferring the heated liquid metal to the first container containing the semiconductor substrate.

[0011] Optionally, the packaging method is performed in a glove box, and the glove box is filled with a protective gas.

[0012] Optionally, the step of reducing the pressure in the sealed container to a negative pressure includes: using a vacuum pump to extract the gas in the sealed container to a negative pressure.

[0013] Optionally, after the step of filling the first cavity structure with liquid metal through the first potting hole, the packaging method further comprises: sealing the first potting hole with inorganic glue.

[0014] In order to achieve the above objective, according to one aspect of the present invention, a packaging substrate is provided, which is prepared by any semiconductor substrate packaging method.

[0015] According to another aspect of the present invention, a packaging control method is provided. The packaging control method is applied to a potting system, the potting system is used to package a semiconductor substrate, the potting system includes a vacuum pump, and the packaging control method includes: when the semiconductor substrate is filled with liquid metal, obtaining a first potting state of the liquid metal in the semiconductor substrate; when the first potting state does not satisfy a first preset relationship, controlling the vacuum pump to execute the above-mentioned S2 at least once, until the first potting state satisfies the first preset relationship and stops.

[0016] Optionally, the encapsulation system further includes a glove box and a gas storage tank, the glove box is connected to the gas storage tank via a gas valve, and the encapsulation control method further includes: obtaining the gas concentration in the glove box; when the gas concentration does not satisfy a second preset relationship, controlling the gas valve to open.

[0017] Optionally, the packaging control method further includes: acquiring a first mass of the semiconductor substrate; and determining a volume of the liquid metal in the semiconductor substrate according to the first mass and an initial mass of the semiconductor substrate.

[0018] Optionally, the potting system also includes an operating table. Before the liquid metal is filled into the semiconductor substrate, the packaging control method also includes: obtaining a second potting state of the liquid metal in the reference substrate, wherein the liquid metal in the reference substrate is packaged through a preset program, and the preset program includes: transferring a first container containing liquid metal and a target substrate into a sealed container, reducing the pressure in the sealed container to a negative pressure, and then connecting the sealed container with the outside of the sealed container, so that the liquid metal is filled into the cavity structure of the target substrate through the potting hole of the target substrate, and the target substrate includes a semiconductor substrate and a reference substrate; when the second potting state satisfies the first preset relationship, controlling the operating table and the vacuum pump to package the semiconductor substrate, and the operating table is used to execute the preset program.

[0019] By applying the technical solution of the present invention, a packaging method for a semiconductor substrate is provided, wherein the semiconductor substrate has a first cavity structure, and the first cavity structure is connected to the outside of the semiconductor substrate through at least one first encapsulation hole, and the packaging method comprises: placing a first container containing liquid metal and a semiconductor substrate in a closed container; after reducing the pressure in the closed container to a negative pressure, the closed container is connected to the outside of the closed container to fill the liquid metal into the first cavity structure through the first encapsulation hole. Through the present application, due to the moment when the closed container under negative pressure is connected to the outside of the closed container, the pressure of the atmospheric pressure area outside the closed container is higher than the pressure in the closed container, thereby forming a pressure difference between the first cavity structure of the semiconductor substrate of the closed container and the external atmospheric pressure, at this time, in order to balance the pressure difference between the closed container and the outside of the closed container, the liquid in the closed container will be forced into the first cavity structure of the semiconductor substrate by the higher atmospheric pressure. It can be understood that the driving force generated by the air pressure difference is much greater than the resistance generated by the surface tension of the liquid metal. Therefore, even if the surface tension of the liquid metal is large, the packaging method of the present application can still enable the liquid metal to flow smoothly and fill the first cavity structure without being affected by the surface tension of the liquid metal, thereby solving the technical problem in the prior art that the liquid metal cannot be effectively encapsulated into a tiny packaging substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 The encapsulation device of the TSV adapter board in the prior art is shown;

[0022] Figure 2 A schematic structural diagram of a silicon substrate according to an embodiment of the present invention is shown;

[0023] Figure 3 A schematic structural diagram of a potting system according to an embodiment of the present invention is shown;

[0024] Figure 4 A schematic structural diagram of a silicon glass substrate after encapsulating 80% of the cavity volume with gallium according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] As described in the background, in highly integrated electronic chip packaging, further improving passive heat dissipation capabilities faces challenges due to space limitations. To address this issue, liquid metal is considered to be an ideal heat dissipation material due to its high thermal conductivity, high boiling point, low melting point, low thermal expansion coefficient, and anti-magnetic properties, allowing liquid metal to withstand extreme temperature changes during packaging and operation while maintaining the performance of electronic devices, such as gallium-based alloys. Therefore, the solution proposed in the prior art is to embed liquid metal in the packaging substrate. For example, the current potting process of the existing embedded liquid metal TSV adapter board is mainly in a nitrogen atmosphere, through a customized silicone heating belt to heat the Teflon syringe and combine it with a programmable heating array tray to pot the gallium-based liquid metal above the melting point into the embedded cavity of the TSV adapter board. However, due to the large surface tension of gallium-based liquid metal, when the cavity height of the adapter plate is very low, the force of the syringe is far from enough to fill the liquid metal into the inside of the adapter plate, so that the liquid metal can only exist near the filling hole, and the Teflon syringe needle is relatively long, much longer than the height of the adapter plate. When the syringe needle enters the filling hole, it is easy to reach the bottom of the adapter plate, thereby blocking the filling hole and affecting the filling effect. Therefore, the above process method has a poor filling effect when the syringe is filled through the filling hole for the adapter plate with a narrow cavity height (100μm or even lower). On this basis, in order to solve the technical problem that the prior art cannot effectively fill liquid metal into a tiny packaging substrate, the present application provides a semiconductor substrate packaging method, a packaging substrate and a packaging control method.

[0029] According to a first aspect of the present application, a packaging method for a semiconductor substrate is provided, wherein the semiconductor substrate has a first cavity structure, and the first cavity structure is connected to the outside of the semiconductor substrate through at least one first encapsulation hole, and the packaging method comprises the following steps:

[0030] S1: transferring the first container containing the liquid metal and the semiconductor substrate into a sealed container;

[0031] S2: After reducing the pressure in the sealed container to negative pressure, the sealed container is connected to the outside of the sealed container to fill the liquid metal into the first cavity structure through the first filling hole.

[0032] Specifically, when both the liquid metal and the semiconductor substrate are placed in the first container, in order to facilitate subsequent pouring so that the liquid metal fills the first cavity structure, the liquid metal may just cover the semiconductor substrate.

[0033] Specifically, the liquid metal may be a gallium-based liquid metal.

[0034] Specifically, Figure 2 As shown, the semiconductor substrate may be a silicon substrate.

[0035] Exemplarily, the method for preparing the silicon substrate may include: providing a first silicon substrate and a second silicon substrate; etching the second silicon substrate to form a groove on one side of the second silicon substrate, wherein a plurality of silicon pillars are spaced apart in the groove; bonding one side of the first silicon substrate to the side of the second silicon substrate having the groove to form a silicon substrate, wherein the silicon substrate has a first cavity structure formed by bonding the first silicon substrate and the second silicon substrate. The silicon substrate may then be etched to form a first encapsulation hole in the silicon substrate, wherein the first encapsulation hole connects the first cavity structure inside the silicon substrate and the outside of the silicon substrate.

[0036] Optionally, before the step of bonding the first silicon substrate and the second silicon substrate, the method for preparing the silicon substrate further includes: epitaxially growing a gallium nitride layer on one side of the first silicon substrate, and then etching the gallium nitride with KOH to obtain a patterned first silicon substrate. Then, in the step of bonding the first silicon substrate and the second silicon substrate, the side of the patterned first silicon substrate having the gallium nitride layer can be bonded to the side of the second silicon substrate having the groove, and the gallium nitride layer is located between any two adjacent silicon pillars.

[0037] Optionally, in the step of bonding the first silicon substrate and the second silicon substrate, silicon-silicon bonding may be performed on the first silicon substrate and the second silicon substrate at a high temperature of 1000° C., thereby forming a silicon substrate having a first cavity structure.

[0038] Optionally, before the step of forming the first encapsulation hole in the silicon substrate, a chemical mechanical polishing process may be used to thin the semiconductor substrate after bonding.

[0039] Exemplarily, the thickness of the semiconductor substrate (silicon substrate) may be less than or equal to 100 micrometers. Exemplarily, the first encapsulation hole may be an encapsulation hole with a radius of 0.6 mm, such as Figure 2 shown.

[0040] In the above embodiment, when the first container containing liquid metal and semiconductor substrate is transferred to the sealed container, and the pressure in the sealed container is reduced to negative pressure, and then the sealed container is connected to the outside of the sealed container, due to the moment when the sealed container under negative pressure is connected to the outside of the sealed container, the pressure of the atmospheric pressure area outside the sealed container is higher than the pressure in the sealed container, thereby forming a pressure difference between the first cavity structure of the semiconductor substrate in the sealed container and the external atmospheric pressure. At this time, in order to balance the pressure difference between the sealed container and the outside of the sealed container, the liquid in the sealed container will be forced into the first cavity structure of the semiconductor substrate through the first encapsulation hole of the semiconductor substrate by the higher pressure atmospheric pressure. It can be understood that the driving force generated by the air pressure difference is much greater than the resistance generated by the surface tension of the liquid metal. Therefore, even if the surface tension of the liquid metal is large, the packaging method of the present application can still make the liquid metal flow smoothly and fill the first cavity structure without being affected by the surface tension of the liquid metal, thereby solving the technical problem that the prior art cannot effectively encapsulate the liquid metal into a tiny packaging substrate.

[0041] In some optional embodiments, the packaging method further includes: placing the liquid metal in a second container; placing the second container in a heating device; and transferring the heated liquid metal to the first container containing the semiconductor substrate.

[0042] Specifically, since the fluidity of liquid metal at room temperature is poor, which is not conducive to the encapsulation of semiconductor substrates, in order to improve the fluidity of liquid metal, the above-mentioned embodiment heats the liquid metal by placing the liquid metal in a second container and placing the second container on a heating device for heating, thereby improving the fluidity of the liquid metal.

[0043] Exemplarily, the liquid metal may be heated to 80°C.

[0044] Optionally, the material of the second container may be polystyrene, which will not deform at a heating temperature of about 100° C. It should be noted that the second container cannot be a metal container to prevent the metal from reacting with gallium.

[0045] In some optional embodiments, in order to prevent the liquid metal from being oxidized and to maximize the heat dissipation capacity of the liquid metal in the semiconductor substrate, the packaging method is performed in a glove box, and the glove box is filled with a protective gas.

[0046] Exemplarily, the protective gas may be nitrogen.

[0047] In some optional embodiments, the step of reducing the pressure in the sealed container to a negative pressure includes: using a vacuum pump to extract the gas in the sealed container to a negative pressure.

[0048] In the above embodiment, the gas in the container is extracted by a vacuum pump, so that the number of gas molecules in the sealed container can be reduced, thereby reducing the pressure.

[0049] Exemplarily, the gas in the sealed container may be extracted until the pressure in the sealed container is -0.1 MPa.

[0050] In some optional embodiments, in order to prevent leakage of liquid metal, after the step of filling the liquid metal into the first cavity structure through the first potting hole, the packaging method further comprises: sealing the first potting hole with inorganic glue.

[0051] Optionally, before the step of sealing the first potting hole with inorganic glue, part of the protective gas may be retained inside the first cavity structure, so as to be used for two-phase flow movement of the key liquid metal and the protective gas under the temperature gradient.

[0052] It is explained here that in order to make the semiconductor substrate have good heat dissipation capability, after the step of filling the above-mentioned liquid metal into the above-mentioned first cavity structure through the above-mentioned first potting hole, the potting state of the liquid metal in the semiconductor substrate can also be detected, and then when the potting state reaches the expected state, the above-mentioned inorganic glue is used to seal the first potting hole.

[0053] Optionally, the inorganic glue is a high temperature resistant inorganic glue. After the first potting hole is coated with glue, it can be stored at room temperature for 16 hours, then heated at 150° C. in a constant temperature box for two hours, and then taken out and slowly cooled.

[0054] According to a second aspect of the present application, a packaging substrate is provided, which is prepared by any of the above-mentioned packaging methods for semiconductor substrates.

[0055] Specifically, the above-mentioned packaging substrate can be a TSV adapter board. The preparation method of the TSV adapter board, based on the preparation steps of the above-mentioned semiconductor substrate, can also include: constructing a SiO2 insulating layer by oxidizing a specific area, depositing a barrier layer, and filling metal copper, and then constructing a silicon through hole in the center of the corresponding silicon column in the silicon-silicon bonding sheet. Then, in the sixth step, the lower surface of the silicon wafer is thinned by chemical mechanical grinding, and then the adapter board is rewired by RDL (Redistribution layer) to construct a circuit structure, and then DRIE is used to etch the potting hole on the silicon substrate. In this way, the TSV adapter board with an embedded cavity is manufactured.

[0056] According to a third aspect of the present application, in order to make the filling rate of liquid metal in the semiconductor substrate reach the target filling rate, a packaging control method is provided, and the packaging control method is applied to Figure 3 The encapsulation system shown is used to encapsulate a semiconductor substrate, and the encapsulation system includes a vacuum pump. The encapsulation control method includes: when the semiconductor substrate is filled with liquid metal, obtaining a first encapsulation state of the liquid metal in the semiconductor substrate; when the first encapsulation state does not satisfy a first preset relationship, controlling the vacuum pump to execute the step S2 at least once, and stopping when the first encapsulation state satisfies the first preset relationship.

[0057] Specifically, an X-ray instrument (such as Figure 3 The X-ray instrument box shown in the figure) observes the first encapsulation state of the liquid metal in the semiconductor substrate.

[0058] In the above embodiment, the first preset relationship may be the filling rate of the liquid metal in the semiconductor substrate and the preset target filling rate range of the semiconductor substrate. For example, when the filling rate of the liquid metal in the semiconductor substrate is not within the preset target filling rate range, the vacuum pump may be controlled to extract the sealed container (such as Figure 3 The gas in the vacuum tank shown in the figure is removed, thereby reducing the pressure in the sealed container to a negative pressure, and then the sealed container is connected to the external atmospheric pressure, so that the liquid metal is poured into the first cavity structure of the semiconductor substrate through the first filling hole; and then the first filling state of the liquid metal in the semiconductor substrate is continuously obtained until the filling rate of the liquid metal in the semiconductor substrate is within a preset target filling rate range and the above S2 is stopped.

[0059] like Figure 3As shown, the encapsulation system further includes a glove box and a gas storage tank (nitrogen tank), the glove box is connected to the gas storage tank via a gas valve (control valve), and the encapsulation control method further includes: obtaining the gas concentration in the glove box; when the gas concentration does not satisfy the second preset relationship, controlling the gas valve to open until the gas concentration satisfies the second preset relationship. Optionally, the gas valve can be installed on a connecting conduit, and the connecting conduit is used to connect the glove box and the gas storage tank.

[0060] In the above embodiment, the semiconductor substrate is packaged in a glove box to prevent the liquid from being oxidized. The above second preset relationship can be a gas concentration in the glove box and a preset target gas concentration in the glove box. For example, the gas detector (such as Figure 3 The nitrogen concentration detector shown in the figure detects the gas concentration in the glove box, so that when the gas concentration is not within the target gas concentration range preset in the glove box, the gas valve (control valve) connecting the glove box and the gas storage tank (nitrogen tank) can be controlled to open, until the gas detector (nitrogen concentration detector) detects that the gas concentration in the glove box is within the preset target gas concentration range, and the gas valve (control valve) is closed.

[0061] Alternatively, if Figure 3 As shown, the above-mentioned encapsulation system may further include a heating platform (or heating device) for heating the liquid metal.

[0062] The packaging control method further includes: obtaining a first mass of the semiconductor substrate; and determining a volume of the liquid metal in the semiconductor substrate according to the first mass and an initial mass of the semiconductor substrate.

[0063] Specifically, the initial mass of the semiconductor substrate is the mass before the liquid metal is filled. The mass of the liquid metal filled into the first cavity structure of the semiconductor substrate can be determined based on the difference between the first mass and the initial mass, and then, if the density of the liquid metal is known, the volume of the liquid metal can be determined based on the ratio of the mass and density of the liquid metal.

[0064] Alternatively, if Figure 3 As shown, the above-mentioned encapsulation system may further include an electronic scale with a precision of one ten-thousandth, and the electronic scale with a precision of one ten-thousandth may be used to accurately measure the mass of the semiconductor substrate, thereby obtaining the mass of the liquid metal in the semiconductor substrate.

[0065] In some optional implementations, for the encapsulation state of the liquid metal in the silicon substrate, an X-ray instrument may be used to first observe the encapsulation effect inside the silicon substrate, and then the volume of the liquid metal in the silicon substrate may be accurately determined by weighing the mass.

[0066] The encapsulation system further includes an operation table. Before the liquid metal is filled into the semiconductor substrate, the encapsulation control method further includes: obtaining a second encapsulation state of the liquid metal in the reference substrate, wherein the liquid metal in the reference substrate is encapsulated by a preset program, wherein the preset program includes: placing a first container (such as a container) containing the liquid metal and the target substrate Figure 3 The method comprises the steps of: transferring the container containing liquid metal and substrate as shown in the figure to a closed container, reducing the pressure in the closed container to a negative pressure and then connecting the closed container with the outside of the closed container to fill the liquid metal into the cavity structure of the target substrate through the encapsulation hole of the target substrate, wherein the target substrate includes the semiconductor substrate and the reference substrate; when the second encapsulation state satisfies the first preset relationship, controlling the operating table and the vacuum pump to encapsulate the semiconductor substrate, and the operating table is used to execute the preset program.

[0067] In the above implementation, the reference substrate may be a silicon glass substrate, and the semiconductor substrate may be a silicon substrate. Since silicon is opaque, it is difficult to know the internal encapsulation status during the encapsulation of the silicon substrate. Therefore, in this implementation, the silicon glass substrate is first encapsulated, one side of which is a silicon substrate with silicon columns exposed after etching, and the other side is a glass substrate. Then, silicon and glass are bonded to form a silicon glass substrate. Figure 4 This is a schematic diagram of the structure of the silicon glass substrate. It can be seen that the internal silicon column and the state of the internal cavity (nitrogen and liquid metal gallium) can be clearly seen through one side of the glass substrate. By testing the silicon glass substrate potting process, it can be known whether the second potting state corresponding to the silicon glass substrate satisfies the first preset relationship. It can be understood that if the second potting state corresponding to the silicon glass substrate satisfies the first preset relationship, the silicon substrate can be potted, which will make the potting effect of the silicon substrate better.

[0068] It should be noted that the silicon glass substrate may have a second cavity structure (cavity), and the second cavity structure may be connected to the outside of the silicon glass substrate through at least one second encapsulation hole.

[0069] In some optional embodiments, the encapsulated state of the liquid metal in the silicon glass substrate can be observed with the naked eye first because the glass is transparent, and then the silicon glass substrate can be accurately weighed using an electronic scale with an accuracy of one ten-thousandth. Therefore, when the initial mass of the silicon glass substrate is known, the difference between the weighing and the initial mass can be obtained, and then the volume of the liquid metal in the silicon glass substrate can be determined based on the above difference and the density of the liquid metal.

[0070] In some optional embodiments, the liquid metal in the semiconductor substrate occupies 80% or 60% of the first cavity structure.

[0071] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0072] By applying the technical solution of the present invention, a packaging method for a semiconductor substrate is provided, wherein the semiconductor substrate has a first cavity structure, and the first cavity structure is connected to the outside of the semiconductor substrate through at least one first encapsulation hole, and the packaging method comprises: placing a first container containing liquid metal and a semiconductor substrate in a closed container; after reducing the pressure in the closed container to a negative pressure, the closed container is connected to the outside of the closed container to fill the liquid metal into the first cavity structure through the first encapsulation hole. Through the present application, due to the moment when the closed container under negative pressure is connected to the outside of the closed container, the pressure of the atmospheric pressure area outside the closed container is higher than the pressure in the closed container, thereby forming a pressure difference between the first cavity structure of the semiconductor substrate of the closed container and the external atmospheric pressure, at this time, in order to balance the pressure difference between the closed container and the outside of the closed container, the liquid in the closed container will be forced into the first cavity structure of the semiconductor substrate by the higher atmospheric pressure. It can be understood that the driving force generated by the air pressure difference is much greater than the resistance generated by the surface tension of the liquid metal. Therefore, even if the surface tension of the liquid metal is large, the packaging method of the present application can still enable the liquid metal to flow smoothly and fill the first cavity structure without being affected by the surface tension of the liquid metal, thereby solving the technical problem in the prior art that the liquid metal cannot be effectively encapsulated into a tiny packaging substrate.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for packaging a semiconductor substrate, characterized in that: The semiconductor substrate has a first cavity structure, and the first cavity structure is connected to the outside of the semiconductor substrate through at least one first encapsulation hole. The packaging method includes the following steps: S1: transferring the first container containing the liquid metal and the semiconductor substrate into a sealed container; S2: After reducing the pressure in the sealed container to negative pressure, the sealed container is connected to the outside of the sealed container to fill the liquid metal into the first cavity structure through the first potting hole.

2. The packaging method according to claim 1, characterized in that: The packaging method further comprises: placing the liquid metal in a second container; placing the second container on a heating device; The heated liquid metal is transferred to the first container containing the semiconductor substrate.

3. The packaging method according to claim 1 or 2, characterized in that: The packaging method is performed in a glove box, and the glove box is filled with a protective gas.

4. The packaging method according to claim 1 or 2, characterized in that: The step of reducing the pressure in the closed container to negative pressure comprises: The gas in the sealed container is extracted to a negative pressure using a vacuum pump.

5. The packaging method according to claim 1 or 2, characterized in that: After the step of filling the first cavity structure with the liquid metal through the first potting hole, the packaging method further includes: The first potting hole is sealed with inorganic glue.

6. A packaging substrate, characterized in that: The semiconductor substrate is prepared by the packaging method of any one of claims 1 to 5.

7. A packaging control method, characterized in that: The packaging control method is applied to a potting system, the potting system is used to package a semiconductor substrate, the potting system includes a vacuum pump, and the packaging control method includes: When the semiconductor substrate is filled with liquid metal, obtaining a first encapsulation state of the liquid metal in the semiconductor substrate; In the case where the first potting state does not satisfy the first preset relationship, the vacuum pump is controlled to execute the S2 of claim 1 at least once, and stops when the first potting state satisfies the first preset relationship.

8. The packaging control method according to claim 7, characterized in that: The encapsulation system further includes a glove box and a gas storage tank, wherein the glove box is connected to the gas storage tank via a gas valve, and the encapsulation control method further includes: Obtaining the gas concentration in the glove box; When the gas concentration does not satisfy the second preset relationship, the gas valve is controlled to open.

9. The packaging control method according to claim 8, characterized in that: The packaging control method further includes: obtaining a first quality of the semiconductor substrate; The volume of the liquid metal in the semiconductor substrate is determined according to the first mass and the initial mass of the semiconductor substrate.

10. The packaging control method according to any one of claims 7 to 9, characterized in that: The encapsulation system further includes an operation station. Before the liquid metal is filled into the semiconductor substrate, the packaging control method further includes: Acquiring a second potting state of liquid metal in a reference substrate, wherein the liquid metal in the reference substrate is obtained by packaging through a preset procedure, wherein the preset procedure comprises: transferring a first container containing liquid metal and a target substrate into a sealed container, reducing the pressure in the sealed container to a negative pressure, and then connecting the sealed container with the outside of the sealed container to fill the liquid metal into the cavity structure of the target substrate through the potting hole of the target substrate, wherein the target substrate comprises the semiconductor substrate and the reference substrate; When the second encapsulation state satisfies the first preset relationship, the operating table and the vacuum pump are controlled to encapsulate the semiconductor substrate, and the operating table is used to execute the preset program.

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