Bonding structure, manufacturing method thereof and micro light-emitting diode device

Abstract

The invention relates to a bonding structure, a manufacturing method thereof and a miniature light-emitting diode device, and the method comprises the steps: providing a first substrate and a second substrate, one side of the first substrate comprises a first bonding surface and a first bonding part, one side of the second substrate comprises a second bonding surface and a second bonding part, and the first bonding surface is provided with a first bonding groove; bonding the first bonding surface with the second bonding surface to obtain a pre-bonding structure; determining that a first bonding groove and a second bonding surface in the pre-bonding structure form a sealing cavity with the internal air pressure smaller than one standard atmospheric pressure, and heating a first bonding part and / or a second bonding part in the pre-bonding structure to a molten state in an environment in which the air pressure is smaller than or equal to the air pressure in the sealing cavity, and the first bonding part and the second bonding part are bonded to obtain the bonding structure, so that the self-correcting and ultrahigh-precision bonding structure is provided, and the bonding yield is high.

Description

[Technical field]

[0001] The present application relates to the field of semiconductor light emitting technology, and in particular to a bonding structure and a manufacturing method thereof, and a micro light emitting diode device. [Background technology]

[0002] With the continuous development of semiconductor technology, the requirements for chip computing power and storage density are getting higher and higher, and multi-chip stacking has emerged; or the display driver chip and the display light-emitting chip (module) are stacked vertically to achieve higher PPI (Pixels Per Inch). The density of solder joints between stacked chips is required to be higher and higher in order to achieve higher performance and higher signal or current transmission density, so the bonding accuracy of the two chips is required to be higher and higher.

[0003] However, existing bonding technologies have the problem of difficulty in balancing bonding accuracy and bonding yield. [Summary of the invention]

[0004] The embodiments of the present application provide a bonding structure and a manufacturing method thereof, as well as a micro light emitting diode device, so as to improve the bonding yield while ensuring high bonding accuracy.

[0005] In order to solve the above problems, an embodiment of the present application provides a method for manufacturing a bonding structure, which includes: providing a first substrate and a second substrate, one side of the first substrate includes a first bonding surface and a first bonding portion, one side of the second substrate includes a second bonding surface and a second bonding portion, and the first bonding surface is provided with a first bonding groove; bonding the first bonding surface to the second bonding surface to obtain a pre-bonded structure; determining that the first bonding groove and the second bonding surface in the pre-bonded structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and heating the first bonding portion and / or the second bonding portion in the pre-bonded structure to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, so that the first bonding portion is bonded to the second bonding portion to obtain a bonding structure.

[0006] Among them, one of the first bonding part and the second bonding part is a solder bump, and the other of the first bonding part and the second bonding part is a contact pad; in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, the first bonding part and / or the second bonding part in the pre-bonding structure are heated to a molten state so that the first bonding part is bonded to the second bonding part to obtain a bonding structure, including: in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, the solder bump is heated to a molten state so that the solder bump in the molten state wets the contact pad; the solder bump in the molten state is cooled to a solid state, and the solid solder bump is welded together with the contact pad to obtain a bonding structure.

[0007] The method comprises: placing the pre-bonded structure in a reflow oven, and then evacuating the reflow oven to a pressure of 1.3×10 -7 ~0.05MPa, and heating the solder bump to 150~350℃ to melt the solder bump, the solder bump in the molten state infiltrates the contact pad, and the surface tension of the solder bump in the molten state pulls the contact pad to a position where the surface tension is balanced; cooling the solder bump in the molten state to a solid state, and welding the solid solder bump and the contact pad together, including: cooling the solder bump in the molten state to less than or equal to 60℃ to solidify the solder bump in the molten state, and welding the solid solder bump and the contact pad together.

[0008] Among them, bonding the first bonding surface to the second bonding surface to obtain a pre-bonded structure includes: executing the step of bonding the first bonding surface to the second bonding surface until the first bonding groove of the first bonding surface and the second bonding surface form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, thereby obtaining a pre-bonded structure.

[0009] Bonding the first bonding surface to the second bonding surface includes: aligning and bonding the first bonding surface to the second bonding surface in an environment where the air pressure is less than 1 standard atmospheric pressure, and then applying pressure to the first substrate and / or the second substrate; and releasing the pressure.

[0010] Among them, in an environment where the air pressure is less than 1 standard atmosphere, the first bonding surface is aligned and bonded with the second bonding surface, and then pressure is applied to the first substrate and / or the second substrate, including: in an environment where the air pressure is less than or equal to 0.9 standard atmosphere, the first bonding surface is aligned and bonded with the second bonding surface, and then pressure is applied to the first substrate and / or the second substrate; releasing the pressure includes: in an environment where the air pressure is greater than or equal to 1 standard atmosphere, releasing the pressure.

[0011] In which, when the first bonding surface is in contact with the second bonding surface and the center of the first bonding surface coincides with the center of the second bonding surface, the first bonding portion overlaps with the second bonding portion, and the distance between the outer edge of the second bonding surface and the opening edge of the first bonding groove is smaller than the distance between the edge of the first side of the first bonding portion and the edge of the second side of the second bonding portion, wherein the first side and the second side are two sides opposite to each other in a direction parallel to the first substrate.

[0012] Wherein, providing a first substrate includes: providing a first original substrate, the first original substrate including one or more semiconductor structures; depositing a conductive material on an electrical interconnection region on a surface of the semiconductor structure of the first original substrate to form a first bonding block and a first bonding portion having a first bonding groove, the first bonding block and the first bonding portion being used to electrically connect the semiconductor structure of the first original substrate with the second substrate.

[0013] Wherein, a conductive material is deposited on the electrical interconnection area on the surface of the semiconductor structure of the first original substrate to form a first bonding block with a first bonding groove and a first bonding portion, including: depositing metal material by magnetron sputtering on the first electrical interconnection area on the surface of the semiconductor structure of the first original substrate to form a first bonding block with a first bonding groove, and depositing metal material on the second electrical interconnection area on the surface of the semiconductor structure of the first original substrate to form a first bonding portion.

[0014] Among them, the second bonding surface is provided with a second bonding groove; the first bonding groove and the second bonding surface in the pre-bonding structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, including: the first bonding groove and the second bonding groove in the pre-bonding structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure.

[0015] In order to solve the above problems, an embodiment of the present application also provides a bonding structure, which includes: a first substrate, one side of the first substrate includes a first bonding surface and a first bonding portion, and the first bonding surface is provided with a first bonding groove; a second substrate, one side of the second substrate includes a second bonding surface and a second bonding portion, the second bonding surface is bonded to the first bonding surface, the second bonding portion is bonded to the first bonding portion, and the second bonding surface and the first bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and the center of the first bonding portion is aligned with the center of the second bonding portion in a direction perpendicular to the first substrate.

[0016] One of the first bonding portion and the second bonding portion is a solder bump, the other of the first bonding portion and the second bonding portion is a contact pad, and the solder bump wraps the surface of the contact pad.

[0017] In which, when the first bonding surface is in contact with the second bonding surface and the center of the first bonding surface coincides with the center of the second bonding surface, the first bonding portion overlaps with the second bonding portion, and the distance between the outer edge of the second bonding surface and the opening edge of the first bonding groove is smaller than the distance between the edge of the first side of the first bonding portion and the edge of the second side of the second bonding portion, wherein the first side and the second side are two sides opposite to each other in a direction parallel to the first substrate.

[0018] The first substrate includes a first original substrate, a first bonding block with a first bonding groove, and a first bonding portion, wherein the first original substrate includes one or more semiconductor structures, the first bonding block and the first bonding portion include conductive materials, and are respectively arranged on a first electrical interconnection area and a second electrical interconnection area on the surface of the semiconductor structure.

[0019] Wherein, the conductive material is a metal material.

[0020] The first bonding groove runs through the first bonding block.

[0021] Among them, the second bonding surface is provided with a second bonding groove; the second bonding surface and the first bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, including: the first bonding groove and the second bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure.

[0022] The distance between the outer edge of the first bonding surface and the opening edge of the first bonding groove is greater than or less than the distance between the outer edge of the second bonding surface and the opening edge of the second bonding groove.

[0023] The second substrate includes a second original substrate and a second bonding block, the second bonding block and the second bonding portion are arranged on one side of the second original substrate, and the second bonding surface is the surface of the second bonding block facing away from the second original substrate.

[0024] In order to solve the above problems, an embodiment of the present application further provides a micro light emitting diode device, which includes a bonding structure manufactured by any of the above methods, or includes any of the above bonding structures.

[0025] The beneficial effects of the present application are as follows: the bonding structure and the manufacturing method thereof, as well as the micro-light-emitting diode device provided by the present application, are provided by providing a first substrate and a second substrate, one side of the first substrate includes a first bonding surface and a first bonding portion, one side of the second substrate includes a second bonding surface and a second bonding portion, and the first bonding surface is provided with a first bonding groove, and the first bonding surface is bonded to the second bonding surface to obtain a pre-bonded structure, and then the first bonding groove and the second bonding surface in the pre-bonded structure are determined to form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and the first bonding portion and / or the second bonding portion in the pre-bonded structure are heated to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity. , so that the first bonding part is bonded with the second bonding part to obtain a bonding structure, thereby providing a self-correcting, ultra-high precision bonding structure, realizing whether the alignment accuracy of the two pre-bonded substrates reaches the requirement based on whether the first bonding groove and the second bonding surface form a sealed cavity with an internal air pressure less than 1 standard atmosphere during the pre-bonding process of the two substrates, and when the first bonding groove and the second bonding surface form a sealed cavity with an internal air pressure less than 1 standard atmosphere, that is, when the alignment accuracy of the two pre-bonded substrates reaches the requirement, the two substrates will be permanently bonded, thereby ensuring the high bonding accuracy of the two substrates and reducing the yield loss caused by the low-precision bonding of the two substrates.

[0026] Furthermore, the two pre-bonded substrates can achieve self-alignment under the effect of the self-alignment phenomenon generated by the first bonding portion and / or the second bonding portion which are in a molten state during the bonding process between the first bonding portion and the second bonding portion, thereby aligning the center of the first bonding portion with the center of the second bonding portion in a direction perpendicular to the first substrate, further increasing the bonding accuracy and achieving theoretical zero offset. In view of the fact that the two pre-bonded substrates can achieve self-alignment during permanent bonding, a certain degree of alignment offset is allowed when the two substrates are pre-bonded, that is, the requirement for accuracy when pre-bonding the two substrates is reduced, so that relatively low-precision bonding equipment (for example, bonding accuracy ≤±5μm) can be used for pre-bonding to reduce process costs, and the alignment speed of the two substrates can be increased to improve process efficiency.

[0027] Furthermore, the first bonding groove and the second bonding surface in the bonding structure obtained after the two substrates are bonded re-form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and because there is an air pressure difference between the inside and outside of the sealed cavity, the two substrates after bonding will be constantly subjected to the pressure generated by the air pressure difference, which greatly enhances the bonding strength of the two substrates and reduces the bonding strength requirements for the two bonding parts, thereby helping to improve product reliability and yield.

Brief Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a schematic diagram of a process for manufacturing a bonding structure provided in an embodiment of the present application;

[0030] Figure 2 It is a schematic diagram of the effect of the first bonding surface and the second bonding surface being offset provided by an embodiment of the present application;

[0031] Figure 3 is another schematic diagram of the effect of the first bonding surface and the second bonding surface being offset provided by an embodiment of the present application;

[0032] Figure 4 is another schematic diagram of the effect of the first bonding surface and the second bonding surface being offset provided by an embodiment of the present application;

[0033] Figure 5 is another schematic diagram of the effect of the first bonding surface and the second bonding surface being offset provided by an embodiment of the present application;

[0034] Figure 6 is another schematic diagram of the effect of the first bonding surface and the second bonding surface being offset provided by an embodiment of the present application;

[0035] Figure 7 is another schematic diagram of the effect of the first bonding surface and the second bonding surface being offset provided by an embodiment of the present application;

[0036] Figure 8 is a schematic diagram of the cross-sectional structure after step S12 is completed provided in an embodiment of the present application;

[0037] Fig. 9 is another cross-sectional structural schematic diagram after step S12 provided in an embodiment of the present application is completed;

[0038] Fig.10 is another cross-sectional structural schematic diagram after step S12 provided in an embodiment of the present application is completed;

[0039] Fig.11 is a schematic diagram of the cross-sectional structure after step S13 provided in the embodiment of the present application is completed;

[0040] Fig.12 is another cross-sectional structural schematic diagram after step S13 provided in an embodiment of the present application is completed;

[0041] Fig.13is a schematic diagram of a top view of the structure of a first substrate provided in an embodiment of the present application;

[0042] Fig.14 is a schematic diagram of a top view of the structure of a second substrate provided in an embodiment of the present application;

[0043] Fig.15 is a schematic structural diagram of a micro light emitting diode device provided in an embodiment of the present application;

[0044] Fig.16 It is a schematic diagram of the structure of the display device provided in an embodiment of the present application. [Specific implementation method]

[0045] The following is a further detailed description of the embodiments of the present application in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only used to illustrate the embodiments of the present application, but do not limit the scope of the embodiments of the present application. Similarly, the following examples are only some embodiments of the embodiments of the present application rather than all embodiments, and all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the embodiments of the present application.

[0046] When describing the structure of a component, when a layer or a region is referred to as being "on" or "above" another layer or another region, it may mean being directly above the other layer or another region, or having other layers or regions between it and the other layer or another region. Also, if the component is turned over, the layer or the region will be "under" or "below" the other layer or another region. In addition, the features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments.

[0047] In addition, the directional terms mentioned in the embodiments of the present application, such as [up], [down], [front], [back], [left], [right], [inside], [outside], [side], etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the embodiments of the present application, rather than to limit the embodiments of the present application. In each of the accompanying drawings, units with similar structures are represented by the same figure numbers. For clarity, the various parts in the drawings are not drawn to scale. In addition, certain related parts may not be shown in the drawings.

[0048] With the continuous development of semiconductor technology, the requirements for chip computing power and storage density are getting higher and higher, and multi-chip stacking has emerged; or the display driver chip and the display light-emitting chip (module) are stacked vertically to achieve higher PPI (Pixels Per Inch). The density of solder joints between stacked chips is required to be higher and higher in order to achieve higher performance and higher signal or current transmission density, so the bonding accuracy of the two chips is required to be higher and higher.

[0049] For applications with high bonding accuracy requirements, the method currently commonly used in the industry is to measure the offset after bonding and then compensate the equipment. However, the bonding offset will be affected by environmental vibration, magnetic field, equipment stability, bonding mark accuracy and other factors. It is very difficult to maintain high-precision bonding (<±1.0μm) for a long time, and the requirements for all aspects are very high. High-precision bonding with low yield will increase production costs and reduce benefits. In addition, high-precision bonding (bonding accuracy ≤±1μm) equipment is very expensive and has high maintenance costs. If the bonding accuracy needs to be ≤±0.5μm, the difficulty will be even greater. It is basically impossible to achieve it by simply improving the bonding accuracy of the bonding equipment.

[0050] In view of the above problems, the embodiments of the present application provide a bonding structure and a manufacturing method thereof, a micro light emitting diode device and a display device, by providing a first substrate and a second substrate, one side of the first substrate includes a first bonding surface and a first bonding portion, one side of the second substrate includes a second bonding surface and a second bonding portion, and the first bonding surface is provided with a first bonding groove, and then the first bonding surface is bonded to the second bonding surface to obtain a pre-bonded structure, and then it is determined that the first bonding groove and the second bonding surface in the pre-bonded structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, the first bonding portion and / or the second bonding portion in the pre-bonded structure is heated to a molten state so that the first bonding portion is bonded to the second bonding portion to obtain a bonding structure, thereby providing a self-correcting, ultra-high precision bonding structure that can ensure high bonding precision of the two substrates. The invention provides a high degree of precision and high bonding strength, reduces the yield loss caused by low-precision bonding of the two substrates, and the two pre-bonded substrates can achieve self-alignment under the action of the self-alignment phenomenon generated by the first bonding part and / or the second bonding part in a molten state during the bonding process of the first bonding part and the second bonding part, so that the center of the first bonding part is aligned with the center of the second bonding part in a direction perpendicular to the first substrate, further increasing the bonding accuracy and achieving theoretical zero offset. In view of the fact that the two pre-bonded substrates can achieve self-alignment in subsequent processes, a certain degree of alignment offset is allowed when the two substrates are pre-bonded, that is, the requirement for accuracy when the two substrates are pre-bonded is reduced, so that relatively low-precision bonding equipment (for example, bonding accuracy ≤±5μm) can be used for pre-bonding to reduce process costs, and the alignment speed of the two substrates can be increased to improve process efficiency.

[0051] The following is a detailed description with reference to specific embodiments. It should be noted that the embodiments of the present application can be presented in various forms, some examples of which will be described below.

[0052] See also Figure 1 , Figure 1: is a schematic diagram of a process for manufacturing a bonding structure provided in an embodiment of the present application. The specific process of the method for manufacturing the bonding structure may be as follows:

[0053] Step S11: providing a first substrate and a second substrate, wherein one side of the first substrate includes a first bonding surface and a first bonding portion, one side of the second substrate includes a second bonding surface and a second bonding portion, and the first bonding surface is provided with a first bonding groove.

[0054] Specifically, Figure 2 As shown, when the first bonding surface F1 and the second bonding surface F2 are attached, and the center of the first bonding surface F1 coincides with the center of the second bonding surface F2, the first bonding portion 104 and the second bonding portion 104 may overlap, and the distance D1 between the outer edge of the second bonding surface F2 and the opening edge of the first bonding groove 103 may be smaller than the distance d between the edge of the first side of the first bonding portion 104 and the edge of the second side of the second bonding portion 204, wherein the first side and the second side are two sides opposite to each other in a direction parallel to the first substrate. In addition, the opening width W1 of the first bonding groove 103 may be greater than or equal to the above-mentioned distance d.

[0055] So, like Figure 3 As shown, when the first bonding surface F1 and the second bonding surface F2 are in contact with each other, when the offset distance S1 between the center of the first bonding surface F1 and the center of the second bonding surface F2 is less than or equal to the above-mentioned distance D1, the second bonding surface F2 can seal the first bonding groove 103, and the second bonding portion 204 and the first bonding portion 104 can at least partially overlap.

[0056] Moreover, if Figure 4 As shown, when the first bonding surface F1 and the second bonding surface F2 are in contact with each other, when the offset distance S1 between the center of the first bonding surface F1 and the center of the second bonding surface F2 is greater than the above-mentioned distance D1, the second bonding surface F2 cannot seal the first bonding groove 103, and the second bonding portion 204 is completely offset from the first bonding portion 104.

[0057] Therefore, the offset amount (i.e., offset distance S1) when the first bonding surface F1 and the second bonding surface F2 are bonded needs to be less than or equal to the above-mentioned spacing D1, so that the second bonding surface F2 can seal the first bonding groove 103. In addition, because the above-mentioned spacing D1 is less than the maximum allowable offset amount (i.e., the above-mentioned spacing d) when the first bonding part 104 and the second bonding part 204 are bonded, therefore, when the offset amount when the first bonding surface F1 and the second bonding surface F2 are bonded is less than or equal to the above-mentioned spacing D1, that is, when the second bonding surface F2 can seal the first bonding groove 103, the offset amount when the first bonding part 104 and the second bonding part 204 are bonded can be less than the maximum allowable offset amount, thereby meeting the alignment accuracy requirement of the pre-bonding of the first substrate and the second substrate.

[0058] In some embodiments, Figure 5 As shown, the second bonding surface F2 may be provided with a second bonding groove 203. Specifically, when the first bonding surface F1 is in contact with the second bonding surface F2, and the center of the first bonding surface F1 coincides with the center of the second bonding surface F2, the distance D1 between the outer edge of the second bonding surface F2 and the opening edge of the first bonding groove 103, and / or the distance D2 between the outer edge of the first bonding surface F1 and the opening edge of the second bonding groove 203 may be smaller than the above-mentioned distance d. Moreover, the opening width W1 of the first bonding groove 103 and the opening width W2 of the second bonding groove 203 may both be greater than or equal to the above-mentioned distance d.

[0059] So, like Figure 6 As shown, when the first bonding surface F1 and the second bonding surface F2 are in contact with each other, when the offset distance S1 between the center of the first bonding surface F1 and the center of the second bonding surface F2 is less than or equal to the minimum value of the above-mentioned spacing D1 and the above-mentioned spacing D2, the second bonding groove 203 can be sealed and connected with the first bonding groove 103, and the second bonding part 204 and the first bonding part 104 can at least partially overlap.

[0060] Moreover, if Figure 7 As shown, when the first bonding surface F1 and the second bonding surface F2 are in contact with each other, when the offset distance S1 between the center of the first bonding surface F1 and the center of the second bonding surface F2 is greater than any one of the above-mentioned spacing D1 and the above-mentioned spacing D2, the second bonding groove 203 cannot be sealed and connected with the first bonding groove 103, and the second bonding part 204 is completely offset from the first bonding part 104.

[0061] Therefore, the offset amount (i.e., offset distance S1) when the first bonding surface F1 and the second bonding surface F2 are bonded needs to be less than or equal to the spacing D1 and the spacing D2, so that the second bonding groove 203 can be sealed and connected with the first bonding groove 103. In addition, because the spacing D1 and the spacing D2 are both less than the maximum allowable offset amount (i.e., the spacing d) when the first bonding part 104 and the second bonding part 204 are bonded, when the offset amount when the first bonding surface F1 and the second bonding surface F2 are bonded is less than the spacing D1 and the spacing D2, that is, when the first bonding groove 103 can be sealed and connected with the second bonding groove 203, the offset amount when the first bonding part 104 and the second bonding part 204 are bonded can be less than the spacing d, thereby meeting the alignment accuracy requirement of the pre-bonding of the first substrate and the second substrate.

[0062] In addition, it should be noted that when the offset when the first bonding portion 104 and the second bonding portion 204 are bonded is less than or equal to the above-mentioned spacing d, the first bonding portion 104 and the second bonding portion 204 will completely overlap or partially overlap, thereby enabling the first bonding portion 104 and the second bonding portion 204 to be bonded and connected.

[0063] When the offset of the first bonding portion 104 and the second bonding portion 204 during bonding is greater than the distance d, the first bonding portion 104 and the second bonding portion 204 will be completely offset without overlap, thereby making it impossible to bond the first bonding portion 104 and the second bonding portion 204 together.

[0064] Specifically, the maximum allowable offset when the first bonding portion 104 and the second bonding portion 204 are bonded (that is, the distance d) can be determined according to the size of the first bonding portion 104 and the second bonding portion 204. For example, the maximum allowable offset can be increased by increasing the size of the first bonding portion 104 and the second bonding portion 204. In some examples, the size of the first bonding portion 104 and the second bonding portion 204 can be 0.5 to 1000 μm.

[0065] Furthermore, it can be understood that, in this embodiment, by designing the sizes of the first bonding surface F1, the second bonding surface F2, the first bonding groove 103 and the second bonding groove 104 according to the maximum allowable offset when the first bonding part 104 and the second bonding part 204 are bonded (that is, the above-mentioned spacing d), it is possible to convert a more difficult problem (that is, whether the offset when the first bonding part 104 and the second bonding part 204 are bonded is greater than the maximum allowable offset) into another simpler problem (that is, whether the first bonding groove 103 is sealed by the second bonding surface F2 after the first bonding surface F1 and the second bonding surface F2 are bonded), so as to reduce the difficulty of detecting whether the offset of the pre-bonded first substrate and the second substrate meets the pre-bonding alignment accuracy requirement.

[0066] In some specific embodiments, Figure 5 As shown, the distance between the outer edge of the first bonding surface F1 and the opening edge of the first bonding groove 103 can be greater than or less than the distance between the outer edge of the second bonding surface F2 and the opening edge of the second bonding groove 203; the opening width W1 of the first bonding groove 103 can be greater than or less than the opening width W2 of the second bonding groove 203. In other words, the first bonding groove 103 and the second bonding groove 203 can have different sidewall thicknesses and / or opening widths. In this way, by adjusting the sidewall thickness of the first bonding groove 103 and / or the second bonding groove 203, and / or by adjusting the opening width of the first bonding groove 103 and / or the second bonding groove 203, a smaller spacing d can be accommodated, thereby achieving higher pre-bonding alignment accuracy.

[0067] In some examples, the distance between the outer edge of the first bonding surface F1 and the opening edge of the first bonding groove 103 may be 0.5-1000 μm, the distance between the outer edge of the second bonding surface F2 and the opening edge of the second bonding groove 203 may be 0.5-1000 μm, the opening width of the first bonding groove 103 may be 0.5-5 mm, and the opening width of the second bonding groove 203 may be 0.5-5 mm. The above-mentioned distance D1 and the above-mentioned distance D2 may be greater than or equal to 1.0 μm.

[0068] Furthermore, for ease of understanding, the following is a specific description using the above-mentioned spacing d of 1.0 μm as an example, the spacing between the outer edge of the first bonding surface F1 and the opening edge of the first bonding groove 103 is 0.5 μm, the opening width W1 of the first bonding groove 103 is 3.0 μm, the spacing between the outer edge of the second bonding surface F2 and the opening edge of the second bonding groove 203 is 1.5 μm, and the opening width W2 of the second bonding groove 203 is 2.0 μm. Based on this, it can be calculated that: the spacing D1 between the outer edge of the second bonding surface F2 and the opening edge of the first bonding groove 103 is 1.0 μm; the spacing D2 between the outer edge of the first bonding surface F1 and the opening edge of the second bonding groove 203 is 1.0 μm. Therefore, when the offset (i.e., the offset distance S1) when the above-mentioned first bonding surface F1 and the second bonding surface F2 are bonded is greater than 1.0 μm, the second bonding groove 203 and the first bonding groove 103 will not be sealed and connected.

[0069] Step S12: Bonding the first bonding surface to the second bonding surface to obtain a pre-bonded structure.

[0070] The schematic cross-sectional structure diagram after the first bonding surface F1 and the second bonding surface F2 are bonded can be as follows: Figure 8 , Fig. 9 or Fig.10shown.

[0071] In this embodiment, by designing the sizes of the first bonding surface F1, the second bonding surface F2 and the first bonding groove 103 according to the maximum allowable offset when the first bonding portion 104 and the second bonding portion 204 are bonded (that is, the above-mentioned spacing d), it is possible to convert a relatively difficult problem (that is, whether the offset when the first bonding portion 104 and the second bonding portion 204 are bonded is greater than the maximum allowable offset) into another relatively simple problem (that is, whether the first bonding groove 103 is sealed by the second bonding surface F2 after the first bonding surface F1 and the second bonding surface F2 are bonded), thereby reducing the difficulty of detecting whether the offset of the pre-bonded first substrate 100 and the second substrate 200 meets the pre-bonding alignment accuracy requirement.

[0072] Specifically, Figure 8 or Fig. 9 As shown, after the first bonding surface F1 is bonded to the second bonding surface F2, if the first bonding groove 103 and the second bonding surface F2 are sealed to form a sealed cavity 300 with an internal air pressure less than 1 standard atmosphere, it can be considered that the offset of the pre-bonded first substrate 100 and the second substrate 200 meets the pre-bonding alignment accuracy requirement, and the offset when the above-mentioned first bonding portion 104 and the second bonding portion 204 are bonded will be less than the maximum allowable offset, so that the above-mentioned first bonding portion 104 and the second bonding portion 204 can be bonded and connected.

[0073] Specifically, Fig.10 As shown, after the first bonding surface F1 and the second bonding surface F2 are bonded, if the first bonding groove 103 and the second bonding surface F2 are not sealed to form a sealed cavity 300 with an internal air pressure less than 1 standard atmosphere, it can be considered that the offset of the pre-bonded first substrate 100 and the second substrate 200 does not meet the pre-bonding alignment accuracy requirement, and the offset when the first bonding portion 104 and the second bonding portion 204 are bonded will be greater than the maximum allowable offset, and the bonding connection between the first bonding portion 104 and the second bonding portion 204 cannot be achieved.

[0074] Furthermore, it should be noted that, in the present embodiment, the first bonding surface F1 and the second bonding surface F2 can be bonded under the condition that the air pressure inside the sealed cavity 300 formed by the sealing of the first bonding groove 103 and the second bonding surface F2 is less than 1 standard atmosphere, thereby ensuring that the air pressure inside the sealed cavity 300 formed by the sealing of the first bonding groove 103 and the second bonding surface F2 can be less than 1 standard atmosphere.

[0075] In some embodiments, the above step S12 may include: performing the step of bonding the first bonding surface F1 to the second bonding surface F2, and stopping until the first bonding groove 103 of the first bonding surface F1 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure, thereby obtaining a pre-bonded structure 10. In this way, it can be ensured that the first bonding groove 103 and the second bonding surface F1 in the pre-bonded structure 10 obtained after the above step S12 are completed are sealed to form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure.

[0076] Specifically, when the first bonding groove 103 and the second bonding surface F2 in the pre-bonding structure 10 are sealed to form a sealed cavity 300 with an internal air pressure less than 1 standard atmosphere, due to the air pressure difference between the inside and outside of the sealed cavity 300 under normal pressure (about 1 standard atmosphere), the first substrate 100 and the second substrate 200 in the pre-bonding structure 10 will be constantly subjected to the pressure generated by the air pressure difference, and can be firmly combined together under normal pressure without separation.

[0077] Specifically, the sealed cavity 300 is hollow inside, and the air pressure in the sealed cavity 300 should be appropriate to ensure that the first substrate 100 and the second substrate 200 in the pre-bonded structure 10 will not separate, while avoiding the problem of increased difficulty in opening the sealed cavity 300 in the pre-bonded structure 10 in subsequent process steps due to excessive pressure difference inside and outside the sealed cavity 300.

[0078] In some examples, 1 standard atmosphere is 1.0 atm, and the air pressure in the sealed cavity 300 can be 0.5-0.9 atm, so that in a normal atmospheric environment, the air pressure difference inside and outside the sealed cavity 300 is 0.1-0.5 atm, to ensure that the sealed cavity 300 can provide a sufficiently large suction force to fix the first substrate 100 and the second substrate 200, and to facilitate opening the sealed cavity 300 in the pre-bonded structure 10 in subsequent process steps, thereby reducing the process difficulty.

[0079] Furthermore, it should be noted that if Fig.10As shown, after the first bonding surface F1 and the second bonding surface F2 are bonded, if the first bonding groove 103 is not sealed by the second bonding surface F2, that is, the first bonding groove 103 and the second bonding surface F2 are not sealed to form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure, the first substrate 100 and the second substrate 200 are easily separated or even separated automatically due to the lack of a firm connection between the first substrate 100 and the second substrate 200. Therefore, it can be determined whether the first bonding groove 103 and the second bonding surface F2 are sealed to form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure by detecting whether a firm connection is formed between the first substrate 100 and the second substrate 200 after the first bonding surface F1 and the second bonding surface F2 are bonded.

[0080] In some specific embodiments, the step of bonding the first bonding surface F1 to the second bonding surface F2 is performed until the first bonding groove 103 of the first bonding surface F1 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure, and the pre-bonded structure 10 is obtained, which may include:

[0081] Step S1-1. Bond the first bonding surface F1 and the second bonding surface F2.

[0082] Step S1-2: determine whether the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmosphere; if not, return to and re-execute step S1-1; if yes, obtain a pre-bonded structure 10.

[0083] Specifically, each time the step of bonding the first bonding surface F1 to the second bonding surface F2 is performed, a certain amount of pulling force may be applied to the first substrate 100 and / or the second substrate 200, and it is determined whether the first substrate 100 and the second substrate 200 are separated under the action of the pulling force. Furthermore, when the first substrate 100 and the second substrate 200 are separated under the action of the pulling force, it can be determined that the first bonding groove 103 and the second bonding surface F2 do not form a sealed cavity 300 (e.g., a sealed cavity 300) having an internal pressure less than 1 standard atmosphere. Fig.10 When the first substrate 1000 and the second substrate 200 are not separated under the tensile force, it can be determined that the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 300 (such as Figure 8 and Fig. 9 shown).

[0084] Further, if it is determined that the first bonding groove 103 and the second bonding surface F2 do not form a sealed cavity 300, the step of bonding the first bonding surface F1 and the second bonding surface F2 can be performed again. Then, it can be determined again whether the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure. Repeat this process until the first bonding surface F1 and the second bonding surface F2 are bonded and the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure, and the above step S12 is completed.

[0085] In some specific embodiments, the bonding of the first bonding surface F1 to the second bonding surface F2 may include:

[0086] Step S2-1. In an environment where the air pressure is a first preset air pressure, align and fit the first bonding surface F1 and the second bonding surface F2, and then apply pressure to the first substrate 100 and / or the second substrate 200, wherein the first preset air pressure is less than 1 standard atmospheric pressure.

[0087] Step S2-2. Release the pressure.

[0088] Specifically, Figure 8 and Fig. 9 As shown, when the offset distance S1 between the center of the first bonding surface F1 and the center of the second bonding surface F2 is less than or equal to the above-mentioned spacing D1 after the first bonding surface F1 and the second bonding surface F2 are aligned and bonded, in the process of applying pressure to the first substrate 100 and / or the second substrate 200, the first bonding surface F1 and the second bonding surface F2 will be tightly bonded together under the action of the pressure, so that the first bonding groove 103 of the first bonding surface F1 and the second bonding surface F2 are sealed to form a sealed cavity 300. In addition, the air pressure in the sealed cavity 300 can be equal to the ambient air pressure (i.e., the first preset air pressure) when the sealed cavity 300 is formed, so that the air pressure in the sealed cavity 300 is less than 1 standard atmospheric pressure, so that there is always a pressure difference between the inside and outside of the sealed cavity 300, and the above-mentioned first substrate 100 and the second substrate 200 are continuously pressed together, ensuring that the first substrate 100 and the second substrate 200 in the pre-bonded structure 10 can be firmly combined together and will not separate.

[0089] Furthermore, after the first bonding groove 103 of the first bonding surface F1 is sealed with the second bonding surface F2 to form the sealed cavity 300, in order to ensure that the sealed cavity 300 can be stably in a sealed state, the pressure applied to the first substrate 100 and / or the second substrate 200 can be released in an environment where the air pressure is greater than or equal to 1 standard atmospheric pressure. Accordingly, the above step S2-2 can specifically include: releasing the pressure in an environment where the air pressure is a second preset air pressure. The second preset air pressure is greater than or equal to 1 standard atmospheric pressure.

[0090] In some examples, the first preset air pressure may be less than 0.9 standard atmospheric pressure, for example, 0.5 to 0.9 standard atmospheric pressure. The second preset air pressure may be 1 standard atmospheric pressure.

[0091] Furthermore, in a specific implementation, the first substrate 100 and the second substrate 200 can be placed in a vacuum chamber, the first bonding surface F1 and the second bonding surface F2 are aligned and bonded, and then pressure is applied to the first substrate 100 and / or the second substrate 200, wherein the air pressure in the vacuum chamber is 0.5 to 0.9 standard atmospheric pressure, and the vacuum chamber can be obtained by evacuating a closed chamber. Then, the vacuum chamber can be inflated to 1 standard atmospheric pressure, and then the pressure is released, that is, the step of bonding the first bonding surface F1 and the second bonding surface F2 is performed once.

[0092] Specifically, the above-mentioned application of pressure to the first substrate 100 and / or the second substrate 200 may include: applying pressure to the first substrate 100 and / or the second substrate 200 at a preset force application rate (for example, 0.1 to 0.5 kg / s) to a preset pressure, and maintaining it for a preset time. The preset pressure may be a small pressure less than or equal to 1.0 MPa, for example, 0.01 to 1.0 MPa. The preset time may be 0.5 to 5 min. The direction of the bonding pressure (i.e., the pressure applied to the above-mentioned first substrate 100 and / or the second substrate 200) may be perpendicular to the above-mentioned first substrate 100 and the second substrate 200.

[0093] In some examples, alignment marks may be provided on the first substrate 100 and / or the second substrate 200. Furthermore, aligning and affixing the first bonding surface F1 with the second bonding surface F2 may include: aligning and affixing the first bonding surface F1 with the second bonding surface F2 according to the alignment marks.

[0094] It should also be noted that in a vacuum (i.e., low pressure) environment, during the bonding process of the first bonding surface F1 and the second bonding surface F2, the bonding temperature can be room temperature (e.g., 20-75°C) or low temperature (e.g., 5-15°C), and bonding at room temperature or low temperature can avoid problems such as device failure and thermal stress caused by bonding at high temperature, thereby improving product yield.

[0095] In addition, in the present embodiment, during the step of bonding the first bonding surface F1 to the second bonding surface F2, the bonding pressure used may be a small pressure (≤1.0MPa), thereby reducing the damage to the first substrate 100 and the second substrate 200 caused by the bonding pressure when the first bonding surface F1 and the second bonding surface F2 are in close contact with each other, and after the first bonding surface F1 and the second bonding surface F2 are bonded, if a firm connection is not formed between the first substrate 100 and the second substrate 200, the step of bonding the first bonding surface F1 and the second bonding surface F2 may be performed again until a firm connection is formed between the first substrate 100 and the second substrate 200.

[0096] Specifically, in the above-mentioned embodiment in which the second bonding surface F2 is provided with a second bonding groove 203, the first bonding groove 103 in the above-mentioned pre-bonding structure 10 and the second bonding surface F2 form a sealed cavity 300 with an internal air pressure less than 1 standard atmospheric pressure, which may include: the first bonding groove 103 in the above-mentioned pre-bonding structure 1 and the second bonding groove 203 form a sealed cavity 300 with an internal air pressure less than 1 standard atmospheric pressure.

[0097] In some specific embodiments, the number of the first bonding grooves 103 can be multiple, the number of the second bonding grooves 203 can also be multiple, and the multiple first bonding grooves 103 can correspond to the multiple second bonding grooves 203. Accordingly, the first bonding grooves 103 and the second bonding grooves 203 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure, which can be: the first bonding grooves 103 and the corresponding second bonding grooves 203 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure.

[0098] In addition, it should be noted that, compared with the solution in which the second bonding surface F2 is not provided with the second bonding groove 203, the solution in which the second bonding surface F2 is provided with the second bonding groove 203 in this embodiment is conducive to forming a larger sealing cavity 300 after pre-bonding, thereby further improving the bonding strength.

[0099] Specifically, in the above-mentioned embodiment in which the number of the first bonding grooves 103 is multiple, the multiple first bonding grooves 103 can be evenly spaced to ensure the uniform distribution of the sealed cavity 300 formed by each first bonding groove 103 sealed by the second bonding surface F2, thereby achieving uniform force on the first substrate 100 and the second substrate 200 in the pre-bonding structure 10, further improving the bonding reliability and bonding yield, and thus being able to improve the mechanical strength and reliability of the device.

[0100] Step S13: Determine that the first bonding groove and the second bonding surface in the pre-bonding structure form a sealed cavity with an internal air pressure less than 1 standard atmosphere, and heat the first bonding part and / or the second bonding part in the pre-bonding structure to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, so that the first bonding part is bonded to the second bonding part to obtain a bonding structure.

[0101] The cross-sectional structure diagram after step S13 is completed can be as follows: Fig.11 shown.

[0102] In this embodiment, if Figure 8 and Fig. 9 As shown, after the step of bonding the first bonding surface F1 to the second bonding surface F2 is performed at least once to ensure that the first bonding groove 103 of the first bonding surface F1 and the second bonding surface F2 form a sealed cavity 300 with an internal air pressure less than 1 standard atmosphere, and the pre-bonded structure 10 is obtained, it can be determined that the first bonding groove 103 and the second bonding surface F2 in the pre-bonded structure 10 form a sealed cavity 300 with an internal air pressure less than 1 standard atmosphere, and then the first bonding portion 104 and / or the second bonding portion 204 in the pre-bonded structure 10 can be heated to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity 300, so that the first bonding portion 104 and the second bonding portion 204 are bonded, thereby completing the bonding of the first substrate 100 and the second substrate 200, and obtaining the bonding structure 1 (as shown in FIG. Fig.11 shown).

[0103] Specifically, Figure 8 , Fig. 9 and Fig.11 As shown, the above-mentioned step of heating the first bonding portion 104 and / or the second bonding portion 204 in the pre-bonded structure 10 to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity 300 so that the first bonding portion 104 is bonded to the second bonding portion 204 to obtain the bonding structure 1 may include: opening the sealed cavity 300 in the pre-bonded structure 10, and heating the first bonding portion 104 and / or the second bonding portion 204 to a molten state so that the first bonding portion 104 is bonded to the second bonding portion 204. 4 is bonded to the second bonding portion 204, and the first bonding portion 104 and the second bonding portion 204 in the pre-bonding structure 10 are self-aligned during the bonding process so that the center of the first bonding portion 104 is aligned with the center of the second bonding portion 204 in a direction perpendicular to the first substrate 100, and the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 400 with an internal pressure less than 1 standard atmospheric pressure again, thereby obtaining a bonding structure 1 (such as Fig.11 shown).

[0104] Specifically, in the pre-bonded structure 10, when the air pressure inside the sealed cavity 300 is lower than the air pressure outside the sealed cavity 300, it can be considered that the sealed cavity 300 is in a closed state, and under the action of the air pressure difference inside and outside the sealed cavity 300, the first substrate 100 and the second substrate 200 in the pre-bonded structure 10 can be tightly fixed together without displacement; when the air pressure inside the sealed cavity 300 is greater than or equal to the air pressure outside the sealed cavity 300, it can be considered that the sealed cavity 300 is in an open state, and because there is no longer an air pressure difference inside and outside the sealed cavity 300, the first substrate 100 and the second substrate 200 in the pre-bonded structure 10 can move relative to each other and achieve self-alignment under the action of the self-alignment phenomenon generated by the first bonding portion 104 and / or the second bonding portion 204 in a molten state during the bonding process of the first bonding portion 104 and the second bonding portion 204.

[0105] Furthermore, it should be noted that, in the process of opening the sealed cavity 300 in the pre-bonding structure 10 and heating the first bonding portion 104 and / or the second bonding portion 204 to a molten state so as to bond the first bonding portion 104 to the second bonding portion 204, the first substrate 100 and the second substrate 200 can be placed relative to each other up and down to ensure that after the sealed cavity 300 in the pre-bonding structure 10 is opened, the relative positions of the first substrate 100 and the second substrate 200 will not change due to the gravity of the first substrate 100 and the second substrate 200, and the relative positions of the first substrate 100 and the second substrate 200 will only change due to the self-alignment phenomenon of the first bonding portion 104 and / or the second bonding portion 204 in a molten state during the bonding process of the first bonding portion 104 and the second bonding portion 204, thereby enabling the first substrate 100 and the second substrate 200 to be self-aligned. Therefore, if Figure 8 As shown, when the pre-bonded first substrate 100 and the second substrate 200 have no offset or substantially no offset, it can be ensured that the first substrate 100 and the second substrate 200 after bonding remain without offset or substantially without offset, and an ultra-high precision bonding structure 1 (such as Fig.11 and, as Fig. 9 As shown, when there is an offset between the pre-bonded first substrate 100 and the second substrate 200, and the offset is not greater than the maximum allowable offset, it is also possible to ensure that the first substrate 100 and the second substrate 200 after bonding are free of offset or substantially free of offset, thereby obtaining an ultra-high precision bonding structure 1 (such as Fig.11 shown).

[0106] In addition, if Fig.11As shown, after the first bonding part 104 and the second bonding part 204 complete the bonding, the bonding force between the first bonding part 104 and the second bonding part 204 can provide bonding pressure, so that the first bonding surface F1 and the second bonding surface F2 are bonded again, and the first bonding groove 103 is sealed by the second bonding surface F2 again to form a sealed cavity 400, thereby obtaining a bonding structure 1 including the sealed cavity 400.

[0107] In some specific embodiments, Figures 8 to 11 As shown, one of the first bonding portion 104 and the second bonding portion 204 may be a solder bump 4A, and the other of the first bonding portion 104 and the second bonding portion 204 may be a contact pad 4B. In addition, the first bonding portion 104 and / or the second bonding portion 204 in the pre-bonded structure 10 is heated to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity 300, so that the first bonding portion 104 and the second bonding portion 204 are bonded to obtain the bonding structure 1, which may specifically include:

[0108] S3-1: In an environment where the air pressure is a third preset air pressure, the solder bump 4A is heated to a molten state so that the solder bump 4A in the molten state wets the contact pad 4B, wherein the third preset air pressure is less than or equal to the air pressure in the sealed cavity 300 in the pre-bonded structure 10.

[0109] Specifically, in the process of the solder bump 4A in a molten state wetting the contact pad 4B, the surface tension of the solder bump 4A in a molten state can pull the contact pad 4B to a position where the surface tension is balanced, so that the center of the first bonding portion is aligned with the center of the second bonding portion in a direction perpendicular to the first substrate.

[0110] S3 - 2 : Cooling the molten solder bump 4A to a solid state, and welding the solid solder bump 4A and the contact pad 4B together to obtain a bonding structure 1 .

[0111] In this way, after the surface tension of the molten solder bump 4A pulls the contact pad 4B to a position where the surface tension is balanced, the solder bump 4A is quickly cooled to become solid and tightly bonded to the contact pad 4B, thereby completing the welding of the solder bump 4A and the contact pad 4B. Moreover, after the welding is completed, the bonding force between the contact pad 4B and the solder bump 4A can make the first bonding surface F1 and the second bonding surface F2 fit tightly, so that the first bonding groove 103 is sealed by the second bonding surface F2 again to form a sealed cavity 400, thereby obtaining a self-correcting, ultra-high precision bonding structure 1.

[0112] Specifically, the above S3-1 may include: in an environment where the air pressure is a third preset air pressure, heating the solder bump 4A to a first preset temperature so that the solder bump 4A melts, the solder bump 4A in a molten state wets the contact pad 4B, and the surface tension of the solder bump 4A in a molten state pulls the contact pad 4B to a position where the surface tension is balanced. In addition, the above S3-2 may include: cooling the solder bump 4A in a molten state to a second preset temperature so that the solder bump 4A in a molten state solidifies, and the solid solder bump 4A is welded together with the contact pad 4B.

[0113] Specifically, the melting point temperature of the contact pad 4B may be greater than the melting point temperature of the solder bump 4A, and the first preset temperature may be greater than the melting point temperature of the solder bump 4A and less than the melting point temperature of the contact pad 4B. For example, the first preset temperature may be 150 to 350° C. The second preset temperature may be less than the melting point temperature of the solder bump 4A, for example, less than or equal to 60° C. The first preset pressure may be 1.3×10 -7 ~0.05MPa.

[0114] Furthermore, after the solder bump 4A is heated to the first preset temperature, the solder bump 4A melts into liquid, and because the contact pad 4B has good wettability to the liquid solder bump 4A, the liquid solder bump 4A automatically converges and shrinks toward the center of the contact pad 4B under the surface tension of the liquid solder bump 4A, thereby achieving self-alignment of the solder bump 4A and the contact pad 4B, so that the first substrate 100 and the second substrate 200 (such as Fig. 9 ) becomes a first substrate 100 and a second substrate 200 (as shown) without offset or substantially without offset Fig.11 As shown), and after the solder bump 4A is cooled, the solder bump 4A will become solid and interconnect with the contact pad to form a whole, thereby achieving self-correction and ultra-high precision bonding, which can effectively improve the bonding accuracy, improve the yield rate, and reduce the process cost.

[0115] In a specific implementation, the pre-bonded structure 10 can be placed in a heating chamber (e.g., a reflow oven), and then the heating chamber is evacuated until the air pressure in the heating chamber is a first preset air pressure, so that the air pressure inside the sealed cavity 300 is greater than or equal to the air pressure outside the sealed cavity 300 (i.e., the first preset air pressure), so as to open the sealed cavity 300 in the pre-bonded structure 10, and the first substrate 100 and the second substrate 200 can be heated to 150-300°C at a preset heating rate (e.g., 0.1-5°C / s) to melt the solder bump 4A, and the solder bump 4A in a molten state wets the contact pad 4B, and the surface tension of the solder bump 4A in a molten state pulls the contact pad 4B to a position where the surface tension is balanced. Afterwards, the solder bump 4A can be cooled to below 60°C (for example, room temperature) at a preset cooling rate (for example, 0.5 to 10°C / s) to solidify the solder bump 4A in a molten state, and the solid solder bump 4A is welded together with the contact pad 4B. After the solder bump 4A and the contact pad 4B are welded together, the bonding force between the contact pad 4B and the solder bump 4A makes the first bonding surface F1 and the second bonding surface F2 fit tightly, so that the first bonding groove 103 is again sealed by the second bonding surface F2 to form a sealed cavity 400, thereby obtaining a bonding structure 1 including the sealed cavity 400. Next, gas (for example, nitrogen) can be filled into the heating chamber to 1 standard atmospheric pressure, so that there is an air pressure difference inside and outside the sealed cavity 400 in the bonding structure 1, so that the first substrate 100 and the second substrate 200 in the bonding structure 1 can be constantly subjected to the pressure generated by the air pressure difference, thereby greatly enhancing the bonding force between the first substrate 100 and the second substrate 200, thereby obtaining a bonding structure 1 with self-alignment, ultra-high alignment accuracy and high strength.

[0116] In some examples, the solder bump 4A may be spherical or columnar in shape. The contact pad 4B may be spherical or columnar in shape.

[0117] In some examples, the width of the solder bump 4A may be greater than the width of the contact pad 4B, and the thickness of the solder bump 4A may be greater than or equal to the thickness of the contact pad 4B, so that the solder bump 4A can wrap the contact pad 4B after melting, thereby improving the welding reliability between the solder bump 4A and the contact pad 4B.

[0118] Specifically, in the above bonding structure 1, the solder bump 4A can wrap the surface of the contact pad 4B, and the center of the solder bump 4A and the center of the contact pad 4B can be aligned in a direction perpendicular to the first substrate 100, thereby achieving ultra-high precision bonding.

[0119] Specifically, the material of the solder bump 4A may include metal materials such as indium (In), aluminum (Al), tin (Sn) and / or silver (Ag), and the material of the contact pad 4B may include metal materials such as copper (Cu) and / or aluminum (Al). Moreover, after the first bonding portion 104 and the second bonding portion 204 are welded, the electrical connection between the first substrate 100 and the second substrate 200 in the bonding structure 1 can be achieved, so that the first bonding portion 104 and the second bonding portion 204 have both conductive interconnection and bonding functions.

[0120] Furthermore, it should be noted that, compared with the related art in which the solder bump and the contact pad are welded to provide both conduction and bonding strength until the underfill is completed after bonding, the bonding strength is mainly provided by the underfill. Furthermore, when the solder bump needs to provide both bonding strength and conduction, if the bonding strength is low, during the underfill, due to thermal stress or underfill stress, the solder bumps on the two substrates will be separated from the contact pads, losing their conduction function and thus failing, resulting in reduced yield and increased cost.

[0121] In the present embodiment, because there is a sealed cavity 400 in the bonding structure 1 and there is an air pressure difference inside and outside the sealed cavity 400, the first substrate 100 and the second substrate 200 in the bonding structure 1 will always be subjected to the pressure generated by the air pressure difference, which greatly enhances the bonding strength of the bonding structure 1, and enables the solder bump 4A (i.e., the above-mentioned first bonding portion 104 or the second bonding portion 204) to mainly provide a conductive function, and the bonding strength requirements provided by the solder bump 4A are low, thereby effectively avoiding the problem of providing both a conductive function and a bonding strength after the solder bump 4A is welded to the contact pad 4B, thereby improving the yield and reducing the cost.

[0122] In some embodiments, Figures 8 to 11 As shown, the number of the first bonding parts 104 can be multiple, the number of the second bonding parts 204 can also be multiple, and the multiple first bonding parts 104 can correspond to the multiple second bonding parts 206 one by one. Accordingly, the bonding of the first bonding part 104 in the pre-bonded structure 10 with the second bonding part 204 can include: bonding the first bonding part 104 in the pre-bonded structure 10 with the corresponding second bonding part 204.

[0123] In addition, it should be noted that compared with the traditional wafer and chip bonding process, the traditional wafer and chip bonding process first performs image alignment according to the actual bonding mark pattern, and then applies pressure and temperature to combine the solder bump and the contact pad into one, and then measures the bonding offset. The bonding offset is measured after the bonding is completed, and when the offset does not meet the requirements, rework will damage the solder bump and the contact pad, and the solder bump and the contact pad need to be remade.

[0124] In this embodiment, the bonding process is divided into two steps. First, low-pressure pre-bonding is performed. After confirming that the pre-bonding offset meets the requirements, the solder bump 4A (i.e., the above-mentioned first bonding portion 104 or the second bonding portion 204) is bonded to the contact pad 4B (i.e., the above-mentioned first bonding portion 104 or the second bonding portion 204), thereby avoiding the production of defective products due to the large alignment offset during the pre-bonding of the first substrate 100 and the second substrate 200. In addition, during the bonding process of the solder bump 4A and the contact pad 4B, the closed cavity 300 is in an open state (i.e., the air pressure in the closed cavity 300 is greater than or equal to the air pressure outside the closed cavity 300), and the surface tension of the molten solder bump 4A will pull the contact pad 4B to a position where the surface tension is balanced, so that the centers of the solder bump 4A and the contact pad 4B can be aligned or substantially aligned in a direction perpendicular to the first substrate 100, so as to achieve ultra-high bonding accuracy.

[0125] In addition, in order to achieve high bonding accuracy in the related art, the method used is to measure the offset after bonding and then compensate the equipment. This method is a post-judgment and is irreversible. Therefore, when bonding offset occurs, the bonded chip has its solder bumps welded to the contact pads, so the bonded chip can only be scrapped or the solder bumps must be repaired after rework, which greatly increases the workload and process costs.

[0126] In this embodiment, the two substrates 100 / 200 are pre-bonded first, that is, the first bonding surface F1 is bonded to the second bonding surface F2 first, and then based on whether the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure after the first bonding surface F1 and the second bonding surface F2 are bonded, it is judged whether the alignment accuracy of the two pre-bonded substrates meets the requirements, and in the case that the first bonding groove 103 and the second bonding surface F2 do not form a sealed cavity 300 with an internal pressure less than 1 standard atmospheric pressure, that is, In the case where the alignment accuracy of the two pre-bonded substrates does not meet the requirements, the pre-bonded first substrate 100 and the second substrate 200 are separated, and then the first substrate 100 and the second substrate 200 are pre-bonded again until the first bonding groove 103 and the second bonding surface F2 form a sealed cavity 300 with an internal pressure less than 1 standard atmosphere, that is, until the alignment accuracy of the two pre-bonded substrates meets the requirements, the first bonding portion 104 and the second bonding portion 204 in the obtained pre-bonded structure 10 are bonded to obtain a bonding structure 1 (such as Fig.11 As shown), it not only ensures the high bonding accuracy of the two substrates 100 / 200, but also reduces the defective rate caused by the alignment deviation during pre-bonding, thereby reducing the production cost.

[0127] In the above embodiment, if Figures 8 to 11 as well as Fig.13 As shown, the first substrate 100 may include a first original substrate 101 and a first bonding block 102, the first bonding block 102 and the first bonding portion 104 are arranged on one side of the first original substrate 101, and the first bonding surface F1 may be a surface of the first bonding block 102 facing away from the first original substrate 101. Accordingly, in order to obtain the first substrate 100, the step S11 may include:

[0128] Step S4 - 1 : providing a first original substrate 101 .

[0129] Specifically, the first original substrate 101 can be a chip, a wafer or a wafer block. Among them, the chip can be a driver chip, or can be a light-emitting diode chip (for example, a micro light-emitting diode chip). The wafer can be a driver wafer including multiple driver chips, or can be a light-emitting wafer including multiple light-emitting diode chips. The wafer block can be obtained by wafer cutting, each wafer block includes two or more driver chips, or each wafer block includes two or more light-emitting diode chips.

[0130] Step S4 - 2 : forming a first bonding block 102 and a first bonding portion 104 provided with a first bonding groove 103 on one side of the first original substrate 101 .

[0131] Specifically, a first bonding block 102 having a first bonding groove 103 and a first bonding portion 104 can be formed on one side of the first original substrate 101 through a deposition process and a photolithography process. The deposition process can include a variety of chemical or physical, gas phase or liquid phase deposition processes such as an electron beam deposition process, a magnetron sputtering deposition process, a thermal evaporation process, and an electroplating process.

[0132] In some examples, a bonding material (e.g., a metal material) may be deposited on one side of the first original substrate 101 by a deposition process (e.g., a magnetron sputtering deposition process) to form a bonding material layer. Then, the bonding material layer may be etched by a photolithography process to form a first bonding block 102 having a first bonding groove 103.

[0133] In other examples, a patterned photoresist layer may be formed on one side of the first original substrate 101 by a photolithography process, and then a bonding material may be deposited on the side of the patterned photoresist layer away from the first original substrate 101 by a deposition process to form a bonding material layer. Next, the patterned photoresist layer and the bonding material layer on the surface thereof may be removed by a stripping process to form a first bonding block 102 having a first bonding groove 103.

[0134] In some embodiments, the first bonding block 102 may be electrically insulating. Accordingly, the material of the first bonding block 102 may include insulating materials such as silicon, silicon oxide, gallium nitride and / or silicon nitride. In some examples, the first bonding block 102 may be a single-layer structure, for example, a silicon oxide layer. In other examples, the first bonding block 102 may also be a laminated structure, for example, a laminated structure of silicon nitride / silicon oxide.

[0135] In other embodiments, the first bonding block 102 may be conductive. Accordingly, the material of the first bonding block 102 may include a conductive material, wherein the conductive material may be a metal material such as aluminum (Al), copper (Cu), gold (Au), titanium (Ti) and / or germanium (Ge). In some examples, the first bonding block 102 may be a single-layer metal structure, for example, an aluminum layer, a copper layer or a gold layer. In other examples, the first bonding block 102 may also be a composite multi-layer stacked metal structure, for example, a composite multi-layer stacked metal structure of Ti / Al, or a composite multi-layer stacked metal structure of Ge / Al / Ti / Au.

[0136] Moreover, in the above-mentioned embodiment in which the first bonding block 102 is conductive, the first substrate 100 in the above-mentioned bonding structure 1 can be electrically connected to the second substrate 200 through the first bonding block 102, so that the first bonding block 102 can play a conductive role, electrically connecting the first substrate 100 and the second substrate 200, and realizing that the first bonding block 102 has both conductive interconnection and bonding functions.

[0137] Specifically, Fig.12 As shown, the first original substrate 101 may include one or more first semiconductor structures 110, wherein the surface of the first semiconductor structure 110 has an electrical interconnection area, and the electrical interconnection area on the surface of the first semiconductor structure 110 refers to the area on the surface of the first semiconductor structure 110 that needs to be electrically interconnected with the second substrate 200.

[0138] Furthermore, the above step S4-2 may include: depositing a conductive material on the electrical interconnection region on the surface of the first semiconductor structure 110 of the first original substrate 101 to form a first bonding block 102 and a first bonding portion 104 provided with a first bonding groove 103, wherein the first bonding block 102 and the first bonding portion 104 are used to electrically connect the first semiconductor structure 110 of the first original substrate 101 with the second substrate 200. In specific implementation, a metal material may be deposited by magnetron sputtering on the first electrical interconnection region on the surface of the first semiconductor structure 110 of the first original substrate 101 to form a first bonding block 102 provided with a first bonding groove 103, and a metal material may be deposited on the second electrical interconnection region on the surface of the first semiconductor structure 110 of the first original substrate 101 to form a first bonding portion 104, wherein the first electrical interconnection region and the second electrical interconnection region on the surface of the first semiconductor structure 110 may refer to different regions on the surface of the first semiconductor structure 110 that need to be electrically interconnected with the second substrate 200.

[0139] Exemplarily, the first semiconductor structure 110 may be a driver chip, and the electrically interconnected region on the surface of the first semiconductor structure 110 may be an electrode surface of the driver chip. Exemplarily, the first semiconductor structure 110 may be a light-emitting diode chip, and the electrically interconnected region on the surface of the first semiconductor structure 110 may be an electrode surface of the light-emitting diode chip. Exemplarily, the first semiconductor structure 110 may be a partial structure of a driver chip, and the first bonding block 102 and the first bonding portion 104 may be electrodes of the driver chip that are electrically connected to the first semiconductor structure 110 (e.g., pixel electrodes or common electrodes). Exemplarily, the first semiconductor structure 110 may be a partial structure of a light-emitting diode chip, and the first bonding block 102 and the first bonding portion 104 may be electrodes of the light-emitting diode chip that are electrically connected to the first semiconductor structure 110 (e.g., N-type electrodes or P-type electrodes).

[0140] In some specific embodiments, Fig.12 As shown, the first original substrate 101 may include a plurality of first semiconductor structures 110. Furthermore, the first bonding blocks 102 may be correspondingly formed on the electrical interconnection regions on the surfaces of a part or all of the first semiconductor structures 110, so that the first semiconductor structures 110 of the first original substrate 101 of the entire number can be electrically connected to the second substrate 200 through the corresponding first bonding blocks 102, or the first semiconductor structures 110 of the partial number of the first original substrate 101 can be electrically connected to the second substrate 200 through the corresponding first bonding blocks 102, and the first semiconductor structures 110 other than the partial number of the first semiconductor structures 110 can be electrically connected to the second substrate 200 through the first bonding portions 104 or other conductive structures (e.g., conductive pillars, pads, etc.).

[0141] In some embodiments, Figures 8 to 13 As shown, the first bonding groove 103 may penetrate the first bonding block 102, for example, may penetrate the first bonding block 102 in a direction Z perpendicular to the first original substrate 101, thereby facilitating the formation of a larger sealed cavity 300 after bonding and further improving the bonding strength.

[0142] In some embodiments, Figures 8 to 13 As shown, there may be a plurality of first bonding blocks 102 , and the plurality of bonding blocks 102 may be distributed at intervals.

[0143] Specifically, the above-mentioned multiple first bonding blocks 102 can be evenly spaced to ensure the uniformity of force on the first substrate 100 and the second substrate 200 in the pre-bonding structure 10, and to ensure the uniformity of force on the first substrate 100 and the second substrate 200 in the bonding structure 1.

[0144] Specifically, in the above-mentioned embodiment where the first original substrate 101 includes one or more first semiconductor structures 110, as Fig.12 As shown, one or more first bonding blocks 102 may be formed on the electrical interconnection region on the surface of a first semiconductor structure 110 , and the one or more first bonding blocks 102 have conductive properties to achieve electrical connection between the first semiconductor structure 110 and the second substrate 100 .

[0145] Specifically, in the above-mentioned embodiment where the number of the first bonding portions 104 is plural, Fig.13 As shown, the plurality of first bonding portions 104 may be distributed in a matrix, and the plurality of first bonding blocks 102 may be evenly spaced and distributed on opposite sides or around the plurality of first bonding portions 104 .

[0146] In some examples, such as Fig.13 As shown, the plurality of first bonding blocks 102 may be evenly spaced and distributed in a rectangular array.

[0147] In some examples, such as Fig.13 As shown, a first bonding groove 103 may be provided on the side of the first bonding block 102 facing away from the first original substrate 101, and the first bonding groove 103 may pass through the first bonding block 102 and may be located in the middle of the first bonding block 102, so that the first bonding block 102 is a hollow annular structure.

[0148] In some examples, the opening shape of the first bonding groove 103 can be circular (eg Fig.13 The outer edge of the first bonding block 102 away from the surface of the first original substrate 101 may be in the shape of a circle (as shown in FIG. Fig.13As shown), square, diamond, polygon or irregular shape.

[0149] In some examples, the height of the first bonding block 102 relative to the first original substrate 101 may be in the nanometer level, micrometer level, or millimeter level.

[0150] In some examples, the width of the first bonding block 102 away from the surface of the first original substrate 101 may be in the nanometer level, micrometer level, or millimeter level.

[0151] In some examples, the distance between the outer edge of the first bonding block 102 facing away from the surface of the first original substrate 101 and the opening edge of the first bonding groove 103 may be in the nanometer level, micrometer level or millimeter level.

[0152] In some specific embodiments, the first bonding block 102 and the first bonding groove 103 may be formed simultaneously.

[0153] For example, Figures 8 to 13 As shown, the above-mentioned providing of the first substrate 100 may include: providing a first original substrate 101; forming a bonding material layer (for example, a metal material layer) on one side of the first original substrate 101 through a deposition process; etching the bonding material layer through a photolithography and etching process to form a plurality of first bonding blocks 102 and first bonding grooves 103 that are spaced apart, thereby obtaining the above-mentioned first substrate 100 including the first original substrate 101, the first bonding blocks 102 and the first bonding grooves 103.

[0154] For example, Figures 8 to 13 As shown, the above-mentioned providing of the first substrate 100 may include: providing a first original substrate 101; forming a patterned photoresist layer on one side of the first original substrate 101 through a photolithography process; forming a bonding material layer (for example, a metal material layer) on the side of the patterned photoresist layer away from the first original substrate 101 through a deposition process; removing the patterned photoresist layer and the bonding material layer on the surface thereof through a stripping process to form a plurality of first bonding blocks 102 and first bonding grooves 103 distributed at intervals, thereby obtaining the above-mentioned first substrate 100 including the first original substrate 101, the first bonding blocks 102 and the first bonding grooves 103.

[0155] In the above embodiment, if Figures 8 to 12 as well as Fig.14 As shown, the second substrate 100 may include a second original substrate 201 and a second bonding block 202, the second bonding block 202 and the second bonding portion 204 are arranged on one side of the second original substrate 201, and the second bonding surface F2 may be a surface of the second bonding block 202 facing away from the second original substrate 201. Accordingly, in order to obtain the second substrate 200, the step S11 may include:

[0156] Step S5 - 1 : providing a second original substrate 201 .

[0157] Specifically, the second original substrate 201 can be a chip, a wafer or a wafer block. Among them, the chip can be a driver chip, or can be a light-emitting diode chip (for example, a micro light-emitting diode chip). The wafer can be a driver wafer including a plurality of driver chips, or can be a light-emitting wafer including a plurality of light-emitting diode chips. The wafer block can be obtained by wafer cutting, each wafer block including two or more driver chips, or each wafer block including two or more light-emitting diode chips.

[0158] In some examples, the first substrate 100 and the second substrate 200 may both be chips, so as to apply the manufacturing method of the bonding structure to chip-to-chip (Die to Die) bonding.

[0159] In some other examples, the first substrate 100 and the second substrate 200 may both be wafers, so as to apply the manufacturing method of the bonding structure to wafer to wafer bonding.

[0160] In some other examples, the first substrate 100 and the second substrate 200 may both be wafer blocks, so as to apply the manufacturing method of the bonding structure to block-to-block bonding.

[0161] In other examples, one of the first substrate 100 and the second substrate may be a chip, and the other may be a wafer block or a wafer, so as to apply the manufacturing method of the above-mentioned bonding structure to the bonding of chip to wafer block (Die toblock), or to apply the manufacturing method of the above-mentioned bonding structure to the bonding of chip to wafer (Die towafer).

[0162] In some other examples, one of the first substrate 100 and the second substrate may be a block, and the other may be a wafer, so as to apply the method for manufacturing the bonding structure to block to wafer bonding.

[0163] Step S5 - 2 : forming a second bonding block 202 having a second bonding groove 203 and a second bonding portion 204 on one side of the second original substrate 201 .

[0164] Specifically, a second bonding block 202 and a second bonding portion 204 provided with a second bonding groove 203 may be formed on one side of the second original substrate 201 through a deposition process and a photolithography process. The deposition process may include a variety of chemical or physical, gas phase or liquid phase deposition processes such as an electron beam deposition process, a magnetron sputtering deposition process, a thermal evaporation process, and an electroplating process.

[0165] In some examples, a bonding material (e.g., a metal material) may be deposited on one side of the second original substrate 201 by a deposition process (e.g., a magnetron sputtering deposition process) to form a bonding material layer. Then, the bonding material layer may be etched by a photolithography process to form a second bonding block 202 having a second bonding groove 203.

[0166] In other examples, a patterned photoresist layer can be formed on one side of the second original substrate 201 by a photolithography process, and then a bonding material layer can be formed by depositing a bonding material layer on the side of the patterned photoresist layer facing away from the second original substrate 201 by a deposition process. Then, the patterned photoresist layer and the bonding material layer on the surface thereof can be removed by a stripping process to form a second bonding block 202 having a second bonding groove 203.

[0167] In some embodiments, the second bonding block 202 may be electrically insulating. Accordingly, the material of the second bonding block 202 may include insulating materials such as silicon oxide and / or silicon nitride. In other embodiments, the second bonding block 202 may be conductive. Accordingly, the material of the second bonding block 202 may include conductive materials, and the conductive materials may be metal materials such as aluminum (Al), copper (Cu), gold (Au), titanium (Ti) and / or germanium (Ge). The second substrate 200 in the bonding structure 1 may be electrically connected to the first substrate 100 through the second bonding block 202, so that the second bonding block 202 can play a conductive role, electrically connecting the first substrate 100 and the second substrate 200, so that the second bonding block 202 has both conductive interconnection and bonding functions.

[0168] Specifically, in the above-mentioned embodiment in which the first substrate 100 includes a first original substrate 101 and a first bonding block 102, and the first original substrate 101 includes one or more first semiconductor structures 110, as Fig.12 As shown, the second original substrate 201 may include one or more second semiconductor structures 210, wherein the surface of the second semiconductor structure 210 has an electrical interconnection area, and the electrical interconnection area on the surface of the second semiconductor structure 210 refers to the area on the surface of the second semiconductor structure 210 that needs to be electrically interconnected with the first substrate 100.

[0169] Furthermore, the above step S122 may include: depositing a conductive material on the electrical interconnection region on the surface of the second semiconductor structure 210 of the second original substrate 201 to form a second bonding block 202 and a second bonding portion 204 provided with a second bonding groove 203, wherein the second bonding block 202 and the second bonding portion 204 are used to electrically connect the second semiconductor structure 210 of the second original substrate 201 with the first semiconductor structure 110 of the first original substrate 101. In specific implementation, a metal material may be deposited by magnetron sputtering on the first electrical interconnection region on the surface of the second semiconductor structure 210 of the second original substrate 201 to form a second bonding block 202 provided with a second bonding groove 203, and a metal material may be deposited on the second electrical interconnection region on the surface of the second semiconductor structure 210 of the second original substrate 201 to form a second bonding portion 204, wherein the first electrical interconnection region and the second electrical interconnection region on the surface of the second semiconductor structure 210 may refer to different regions on the surface of the second semiconductor structure 210 that need to be electrically interconnected with the first substrate 100.

[0170] Exemplarily, the second semiconductor structure 210 may be a driver chip, and the electrically interconnected region on the surface of the second semiconductor structure 210 may be an electrode surface of the driver chip. Exemplarily, the second semiconductor structure 210 may be a light-emitting diode chip, and the electrically interconnected region on the surface of the second semiconductor structure 210 may be an electrode surface of the light-emitting diode chip. Exemplarily, the second semiconductor structure 210 may be a partial structure of a driver chip, and the second bonding block 202 and the second bonding portion 204 may be electrodes of the driver chip electrically connected to the second semiconductor structure 210 (e.g., pixel electrodes or common electrodes). Exemplarily, the second semiconductor structure 210 may be a partial structure of a light-emitting diode chip, and the second bonding block 202 and the second bonding portion 204 may be electrodes of the light-emitting diode chip electrically connected to the second semiconductor structure 210 (e.g., N-type electrodes or P-type electrodes).

[0171] In some specific embodiments, Fig.12As shown, the second original substrate 201 may include a plurality of second semiconductor structures 210. Moreover, the second bonding blocks 202 may be correspondingly formed on the electrical interconnection regions on the surfaces of part or all of the second semiconductor structures 210, so that the second bonding blocks 202 and the first bonding blocks 102 can realize the corresponding electrical connection of all the second semiconductor structures 210 on the second original substrate 201 with part or all of the first semiconductor structures 110 on the first original substrate 101, or the second bonding blocks 202 and the first bonding blocks 102 can realize the corresponding electrical connection of part of the second semiconductor structures 210 on the second original substrate 201 with part or all of the first semiconductor structures 110 on the first original substrate 101, and the second semiconductor structures 210 other than the part of the second semiconductor structures 210 can be electrically connected to the first substrate 100 through the second bonding portions 204 or other conductive structures (e.g., conductive pillars, pads, etc.).

[0172] In some embodiments, Figures 8 to 12 as well as Fig.14 As shown, the second bonding groove 203 may penetrate the second bonding block 202, for example, may penetrate the second bonding block 202 in a direction Z perpendicular to the second original substrate 201, thereby facilitating the formation of a larger sealed cavity 300 after bonding, and further improving the bonding strength.

[0173] In some embodiments, Figures 8 to 12 as well as Fig.14 As shown, the number of the second bonding blocks 202 can be multiple, and the multiple second bonding blocks 202 can be evenly spaced to ensure the uniformity of force on the first substrate 100 and the second substrate 200 in the pre-bonding structure 10, and to ensure the uniformity of force on the first substrate 100 and the second substrate 200 in the bonding structure 1.

[0174] In some examples, such as Fig.14 As shown, the plurality of second bonding blocks 202 included in the second bonding block 202 may be evenly spaced and distributed in a rectangular array.

[0175] Specifically, in the above-mentioned embodiment where the number of the second bonding portions 204 is plural, Fig.14 As shown, the plurality of second bonding portions 204 may be distributed in a matrix, and the plurality of second bonding blocks 202 may be evenly spaced and distributed on opposite sides or around the plurality of second bonding portions 204 .

[0176] Specifically, in an embodiment in which a second bonding groove 203 is provided on a side of the second bonding block 202 facing away from the second original substrate 201, Fig.14As shown, the second bonding groove 203 may penetrate the second bonding block 202 , for example, may penetrate the second bonding block 202 in a direction Z perpendicular to the second original substrate 201 .

[0177] In some embodiments, Figures 8 to 12 as well as Fig.14 As shown, at least one second bonding groove 203 is provided on a side of each second bonding block 202 facing away from the second original substrate 201 .

[0178] Specifically, Fig.14 As shown, a second bonding groove 203 may be provided on the side of the second bonding block 202 facing away from the second original substrate 201, and the second bonding groove 203 may pass through the second bonding block 202 and may be located in the middle of the second bonding block 202, so that the second bonding block 202 is a hollow annular structure.

[0179] It should be noted that the specific implementation of the above-mentioned step S5-2 can refer to the specific implementation of the above-mentioned step S4-2, and it is only necessary to replace the first original substrate 101, the first semiconductor structure 110, the first bonding block 102, the second bonding groove 103 and the first bonding part 104 in the specific implementation of the above-mentioned step S4-2 with the second original substrate 201, the second semiconductor structure 210, the second bonding block 202, the second bonding groove 203 and the second bonding part 204 respectively, to obtain the specific implementation of the above-mentioned step S5-2, so it will not be repeated here.

[0180] As can be seen from the above, the method for manufacturing a bonding structure provided in an embodiment of the present application is provided by providing a first substrate and a second substrate, one side of the first substrate includes a first bonding surface and a first bonding portion, one side of the second substrate includes a second bonding surface and a second bonding portion, and the first bonding surface is provided with a first bonding groove, and then the first bonding surface is bonded to the second bonding surface to obtain a pre-bonded structure, and then it is determined that the first bonding groove and the second bonding surface in the pre-bonded structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and the first bonding portion and / or the second bonding portion in the pre-bonded structure are heated to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, so that the first bonding portion is bonded to the second bonding portion to obtain a bonding structure, thereby providing a self-correcting, ultra-high precision bonding structure, which can ensure high bonding accuracy and high bonding strength of the two substrates and reduce The yield loss caused by the low-precision bonding of the two substrates, and the two pre-bonded substrates can achieve self-alignment under the action of the self-alignment phenomenon generated by the first bonding part and / or the second bonding part in a molten state during the bonding process of the first bonding part and the second bonding part, so that the center of the first bonding part is aligned with the center of the second bonding part in a direction perpendicular to the first substrate, further increasing the bonding accuracy and achieving theoretical zero offset. In view of the fact that the two pre-bonded substrates can achieve self-alignment in subsequent processes, a certain degree of alignment offset is allowed when the two substrates are pre-bonded, that is, the requirement for accuracy when the two substrates are pre-bonded is reduced, so that relatively low-precision bonding equipment (for example, bonding accuracy ≤±5μm) can be used for pre-bonding to reduce process costs, and the alignment speed of the two substrates can be increased to improve process efficiency.

[0181] The bonding structure manufactured according to the above method embodiment of the present application is as follows: Fig.11 and Fig.12 As shown, the bonding structure 1 may include a first substrate 100 and a second substrate 200, wherein one side of the first substrate 100 includes a first bonding surface F1 and a first bonding portion 104, and the first bonding surface F1 is provided with a first bonding groove 103, and one side of the second substrate 200 includes a second bonding surface F2 and a second bonding portion 204, the second bonding surface F2 is bonded to the first bonding surface F1, the first bonding portion 104 is bonded to the second bonding portion 204, and the second bonding surface F2 and the first bonding groove 103 form a sealed cavity 400 with an internal air pressure less than 1 standard atmosphere, and the center of the first bonding portion 104 and the center of the second bonding portion 204 can be aligned or substantially aligned in a direction perpendicular to the first substrate 100.

[0182] Specifically, Figure 2As shown, when the first bonding surface F1 and the second bonding surface F2 are attached, and the center of the first bonding surface F1 coincides with the center of the second bonding surface F2, the first bonding portion 104 and the second bonding portion 204 may overlap, and the distance D1 between the outer edge of the second bonding surface F2 and the opening edge of the first bonding groove 103 may be smaller than the distance d between the edge of the first side of the first bonding portion 104 and the edge of the second side of the second bonding portion 204, wherein the first side and the second side are two sides opposite to each other in a direction parallel to the first substrate 100. In addition, the opening width W1 of the first bonding groove 103 may be greater than or equal to the above-mentioned distance d.

[0183] In some embodiments, Fig.11 As shown, one of the first bonding portion 104 and the second bonding portion 204 may be a solder bump 4A, the other of the first bonding portion 104 and the second bonding portion may be a contact pad 4B, and the solder bump 4A may wrap the surface of the contact pad 4B.

[0184] In some embodiments, Fig.11 As shown, the air pressure in the sealed cavity 400 can be 1.3×10 -7 ~0.05MPa.

[0185] In some embodiments, Fig.11 As shown, the first bonding surface F1 can be connected to the second bonding surface F2 at the interface where the first bonding surface F1 contacts the second bonding surface F2 through intermolecular attraction and / or chemical bonds.

[0186] In some embodiments, Fig.12 and Fig.14 As shown, the first substrate 100 may include a first original substrate 101 and a first bonding block 102 having a first bonding groove 103. The first bonding block 102 and the first bonding portion 104 may be disposed on one side of the first original substrate 101, and the first bonding surface F1 may be a surface of the first bonding block 102 facing away from the first original substrate 101.

[0187] Specifically, Fig.12 As shown, the first original substrate 101 may include one or more first semiconductor structures 110, the first bonding block 102 and the first bonding portion 104 may include a conductive material, and may be respectively disposed on a first electrical interconnection region and a second electrical interconnection region on the surface of the first semiconductor structure 110, wherein the conductive material may be specifically a metal material. In this way, the first semiconductor structure 110 of the first original substrate 101 can be electrically connected to the second substrate 200 through the first bonding block 102 and the first bonding portion 104.

[0188] In some specific embodiments, Fig.11 and Fig.13 As shown, there may be a plurality of first bonding blocks 102 , and the plurality of first bonding blocks 102 may be distributed at intervals.

[0189] Specifically, the plurality of first bonding blocks 102 may be evenly spaced. Fig.13 As shown, the plurality of first bonding blocks 102 may be evenly spaced and distributed in a rectangular array.

[0190] In some specific embodiments, Fig.11 and Fig.13 As shown, the first bonding groove 103 may penetrate the first bonding block 102 , for example, may penetrate the first bonding block 102 along a direction Z perpendicular to the first original substrate 101 .

[0191] Specifically, a first bonding groove 103 may be provided on the surface of each first bonding block 102 facing away from the first original substrate 101 , and the first bonding groove 103 may be located in the middle of the first bonding block 102 , so that the first bonding block 102 may be a hollow ring structure.

[0192] In the above embodiment, if Fig.11 As shown, the second bonding surface F2 may be provided with a second bonding groove 203. Furthermore, the second bonding surface F2 and the first bonding groove 103 in the bonding structure 1 form a sealed cavity 400 with an internal pressure less than 1 standard atmospheric pressure, which may include: the first bonding groove 103 and the second bonding groove 203 in the bonding structure 1 form a sealed cavity 400 with an internal pressure less than 1 standard atmospheric pressure.

[0193] Specifically, Figure 5 As shown, the opening width W2 of the second bonding groove 203 may be greater than or equal to the distance d between the edge of the first side of the first bonding portion 104 and the edge of the second side of the second bonding portion 204 .

[0194] Specifically, Figure 5 As shown, the distance D1 between the outer edge of the first bonding surface F1 and the opening edge of the first bonding groove 103 may be greater than or less than the distance D2 between the outer edge of the second bonding surface F2 and the opening edge of the second bonding groove 203. In other words, the sidewall thickness of the first bonding groove 103 may not be equal to the sidewall thickness of the second bonding groove 203.

[0195] In some embodiments, Fig.11 and Fig.14As shown, the second substrate 200 may include a second original substrate 201 and a second bonding block 202 . The second bonding block 202 and the second bonding portion 204 may be disposed on one side of the second original substrate 201 , and the second bonding surface F2 may be the surface of the second bonding block 202 facing away from the second original substrate 201 .

[0196] Specifically, Fig.12 As shown, the second original substrate 201 may include one or more second semiconductor structures 210, and the second bonding block 202 and the second bonding portion 203 may include conductive materials, and may be respectively disposed on the third electrical interconnection region and the fourth electrical interconnection region on the surface of the second semiconductor structure 210. In this way, the second semiconductor structure 210 of the second original substrate 201 can be electrically connected to the first substrate 200 (or the first semiconductor structure 110 of the first original substrate 101) through the second bonding block 202 and the second bonding portion 204.

[0197] In some embodiments, Fig.11 and Fig.14 As shown, there may be a plurality of the second bonding blocks 202 , and the plurality of second bonding blocks 202 may be distributed at intervals, for example, may be arranged at even intervals.

[0198] For example, Fig.14 As shown, the plurality of second bonding blocks 202 may be evenly spaced and distributed in a rectangular array.

[0199] In some specific embodiments, Fig.11 and Fig.14 As shown, the second bonding groove 203 may penetrate the second bonding block 202 , for example, may penetrate the second bonding block 202 along a direction Z perpendicular to the second original substrate 201 .

[0200] Specifically, in the above-mentioned embodiment in which the second bonding groove 103 passes through the second bonding block 202, a second bonding groove 203 can be provided on the surface of the second bonding block 202 facing away from the second original substrate 201, and the second bonding groove 203 can be located in the middle of the second bonding block 202, so that the second bonding block 202 can have a hollow ring structure.

[0201] In the above embodiment, the first substrate 100 (or the first original substrate 101) may be a chip, a wafer or a wafer block. The second substrate 200 (or the second original substrate 201) may be a chip, a wafer or a wafer block.

[0202] It should be noted that the various structures of the bonding structure 1 in this embodiment can refer to the specific implementation methods described in the above method embodiments, so they will not be described in detail here.

[0203] As can be seen from the above, the bonding structure provided in the embodiment of the present application includes a first substrate and a second substrate, wherein one side of the first substrate includes a first bonding surface and a first bonding portion, and the first bonding surface is provided with a first bonding groove, and one side of the second substrate includes a second bonding surface and a second bonding portion, the second bonding surface is bonded to the first bonding surface, the first bonding portion is bonded to the second bonding portion, and the second bonding surface and the first bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and the center of the first bonding portion is aligned with the center of the second bonding portion in a direction perpendicular to the first substrate, thereby providing a self-correcting, ultra-high precision bonding structure, which can ensure high bonding accuracy and high bonding strength of the two substrates, reduce the yield loss caused by low-precision bonding of the two substrates, and the pre-bonded The two substrates can achieve self-alignment under the action of the self-alignment phenomenon generated by the first bonding part and / or the second bonding part in a molten state during the bonding process between the first bonding part and the second bonding part, so that the center of the first bonding part is aligned with the center of the second bonding part in a direction perpendicular to the first substrate, further increasing the bonding accuracy and achieving theoretical zero offset. In view of the fact that the two pre-bonded substrates can achieve self-alignment in subsequent processes, a certain degree of alignment offset is allowed when the two substrates are pre-bonded, that is, the requirement for accuracy when pre-bonding the two substrates is reduced. Therefore, relatively low-precision bonding equipment (for example, bonding accuracy ≤±5μm) can be used for pre-bonding to reduce process costs, and the alignment speed of the two substrates can be increased to improve process efficiency.

[0204] See also Fig.15 , Fig.15 Schematic diagram of the structure of the micro light emitting diode device provided in the embodiment of the present application. Fig.15 As shown, the micro light emitting diode device 20 may include a bonding structure 1 (such as Fig.11 and Fig.12 ), or may include a bonding structure 1 of any of the above embodiments (such as Fig.11 and Fig.12 shown).

[0205] Specifically, Fig.11 and Fig.12As shown, the bonding structure 1 may include a first substrate 100 and a second substrate 200, wherein one side of the first substrate 100 includes a first bonding surface F1 and a first bonding portion 104, and the first bonding surface F1 is provided with a first bonding groove 103, and one side of the second substrate 200 includes a second bonding surface F2 and a second bonding portion 204, the second bonding surface F2 is bonded to the first bonding surface F1, the first bonding portion 104 is bonded to the second bonding portion 204, and the second bonding surface F2 and the first bonding groove 103 form a sealed cavity 400 with an internal air pressure less than 1 standard atmospheric pressure, and the center of the first bonding portion 104 is aligned with the center of the second bonding portion 204 in a direction perpendicular to the first substrate 100.

[0206] In some embodiments, Fig.15 As shown, one of the first substrate 100 and the second substrate 200 may include a micro-LED chip 21, and the other of the first substrate 100 and the second substrate 200 may include a driver chip 22. Moreover, the driver chip 22 is bonded to the micro-LED chip 21. Accordingly, one of the first bonding surface F1 and the second bonding surface F2 may be provided by the surface of the micro-LED chip 21 bonded to the driver chip 22, and the other of the first bonding surface F1 and the second bonding surface F2 may be provided by the surface of the driver chip 22 bonded to the micro-LED chip 21.

[0207] In some specific embodiments, Fig.15 As shown, the micro light emitting diode chip 21 may include a light emitting stack 211 , and the light emitting stack 211 may include a first semiconductor layer 2111 , a light emitting layer 2112 , and a second semiconductor layer 2113 which are sequentially stacked.

[0208] The light emitting layer 2112 may be a quantum well layer, for example, an indium gallium nitride quantum well layer, or an indium gallium nitride / gallium nitride multi-quantum well layer. The first semiconductor layer 2111 and the second semiconductor layer 2113 have different polarities. Specifically, the first semiconductor layer 2111 may be one of an N-type semiconductor layer and a P-type semiconductor layer, and the second semiconductor layer 2113 may be the other of an N-type semiconductor layer and a P-type semiconductor layer. Specifically, the N-type semiconductor layer may be an N-type gallium nitride layer or an N-type gallium arsenide layer, and the P-type semiconductor layer may be a P-type gallium nitride layer or a P-type aluminum gallium nitride layer.

[0209] Specifically, the light emitting stack 211 may be provided with a groove 211A at least penetrating the second semiconductor layer 2113 and the light emitting layer 2112 , and the bottom of the groove 211A is the first semiconductor layer 2111 , so as to expose the first semiconductor layer 2111 .

[0210] In some embodiments, Fig.15 As shown, the micro-LED chip 21 may further include a first conductive layer 212, which is disposed on the first semiconductor layer 2111 at the bottom of the groove 211A, and a first groove 213 is disposed on the side of the first conductive layer 212 away from the first semiconductor layer 2111. Specifically, the micro-LED chip 21 may be bonded to the driving chip 22 through the first conductive layer 212, and the first groove 213 is sealed at the bonding interface between the driving chip 22 and the micro-LED chip 21 to form a sealed cavity 400.

[0211] The first conductive layer 212 and the first groove 213 may be provided by the first bonding block 102 and the first bonding groove 103 in the above embodiment, respectively, or may be provided by the second bonding block 202 and the second bonding groove 203 in the above embodiment, respectively. The light emitting stack 211 may be provided by the first semiconductor structure 110 in the above embodiment, or may be provided by the second semiconductor structure 210 in the above embodiment.

[0212] In some embodiments, Fig.15 As shown, the micro LED chip 21 may further include a second conductive layer 214, which is disposed on a side of the second semiconductor layer 2113 away from the light emitting layer 2112. Furthermore, the micro LED chip 21 may be bonded to the driving chip 22 via the second conductive layer 214.

[0213] Specifically, the micro light emitting diode chip 21 may further include a first polarity electrode (not shown in the figure), and the first polarity electrode is disposed between the first conductive layer 212 and the first semiconductor layer 2111 .

[0214] Specifically, Fig.15 As shown, the micro-LED chip 21 may further include a second polarity electrode 216, which is disposed between the second conductive layer 214 and the second semiconductor layer 2113. Furthermore, the micro-LED chip 21 may further include a current diffusion layer 217, which is located between the second polarity electrode 216 and the second semiconductor layer 2113. Moreover, the current diffusion layer 217 can evenly distribute the current to the entire second semiconductor layer 2113 (for example, the P-type gallium nitride layer), thereby effectively improving the luminous efficiency of the micro-LED chip 21.

[0215] In some embodiments, Fig.15As shown, the micro-LED chip 21 may further include a substrate 218, which is used to support the film structure thereon and may be located on a side of the light-emitting stack 211 away from the driver chip 22. Furthermore, the micro-LED chip 21 may further include a cache layer 219, which may be located between the substrate 218 and the light-emitting stack 211.

[0216] In some embodiments, Fig.15 As shown, the driving chip 22 may include a driving circuit layer 221 and a third conductive layer 222, the third conductive layer 222 is disposed on one side of the driving circuit layer 221, and a third groove 223 is disposed on the side of the third conductive layer 222 away from the driving circuit layer 221. Specifically, the driving chip 22 may be bonded to the micro-LED chip 21 through the third conductive layer 222, and the third groove 223 is sealed at the bonding interface between the driving chip 22 and the micro-LED chip 21 to form a sealed cavity 400.

[0217] The third conductive layer 222 and the third groove 223 may be provided by the first bonding block 102 and the first bonding groove 103 in the above embodiment, or may be provided by the second bonding block 202 and the second bonding groove 203 in the above embodiment, respectively.

[0218] Specifically, in the above embodiment where the micro-LED chip 21 includes the first conductive layer 212, Fig.15 As shown, the first conductive layer 212 and the third conductive layer 222 may be bonded correspondingly to achieve a bonding connection between the driving chip 22 and the micro light emitting diode chip 21 .

[0219] Furthermore, in the above embodiment in which the first conductive layer 212 and the first groove 213 are respectively provided by the first bonding block 102 and the first bonding groove 103 in the above embodiment, the above third conductive layer 222 and the third groove 223 can be respectively provided by the second bonding block 202 and the second bonding groove 203 in the above embodiment.

[0220] Furthermore, in the above embodiment in which the first conductive layer 212 and the first groove 213 are respectively provided by the second bonding block 202 and the second bonding groove 203 in the above embodiment, the above third conductive layer 222 and the third groove 223 can be respectively provided by the first bonding block 102 and the first bonding groove 103 in the above embodiment.

[0221] In some specific embodiments, Fig.15As shown, the driving chip 22 may further include a fourth conductive layer 224 , and the fourth conductive layer 224 is disposed on one side of the driving circuit layer 221 . Furthermore, the driving chip 22 may be bonded to the micro light emitting diode chip 21 through the fourth conductive layer 224 .

[0222] Specifically, in the above embodiment where the micro-LED chip 21 includes the second conductive layer 214, Fig.10 As shown, the second conductive layer 214 and the fourth conductive layer 224 may be bonded correspondingly to achieve a bonding connection between the driving chip 22 and the micro light emitting diode chip 21 .

[0223] Furthermore, one of the second conductive layer 214 and the fourth conductive layer 224 may be provided by the first bonding portion 104 in the above embodiment, and the other of the second conductive layer 214 and the fourth conductive layer 224 may be provided by the second bonding portion 204 in the above embodiment.

[0224] Specifically, in the above embodiment in which the first conductive layer 212 and the first groove 213 are respectively provided by the first bonding block 102 and the first bonding groove 103 in the above embodiment, the second conductive layer 214 and the fourth conductive layer 224 can be respectively provided by the first bonding portion 104 and the second bonding portion 204 in the above embodiment.

[0225] Specifically, in the above embodiment in which the first conductive layer 212 and the first groove 213 are respectively provided by the second bonding block 202 and the second bonding groove 203 in the above embodiment, the second conductive layer 214 and the fourth conductive layer 224 can be respectively provided by the second bonding portion 204 and the first bonding portion 104 in the above embodiment.

[0226] In some examples, the micro-LED device 20 can be applied to any product with a display function, such as electronic paper, mobile phones, tablet computers, televisions, laptop computers, digital photo frames, wearable devices, or navigation devices.

[0227] It should be noted that the micro-light emitting diode device provided in the embodiment of the present application can achieve the beneficial effects that can be achieved by any bonding structure provided in the embodiment of the present application because the bonding structure provided in the embodiment of the present application is provided. Please refer to the previous embodiments for details and will not be repeated here.

[0228] See also Fig.16 , Fig.16 is a schematic diagram of the structure of the display device provided in the embodiment of the present application. Fig.16 As shown, the display device 30 may include a micro light emitting diode device 31 of any of the above embodiments.

[0229] Specifically, the micro light emitting diode device 31 may include a bonding structure manufactured by a method for manufacturing a bonding structure of any of the above embodiments, or may include a bonding structure of any of the above embodiments.

[0230] The bonding structure may include a first substrate and a second substrate. One side of the first substrate includes a first bonding surface and a first bonding portion, and the first bonding surface is provided with a first bonding groove, and one side of the second substrate includes a second bonding surface and a second bonding portion, the second bonding surface is bonded to the first bonding surface, the first bonding portion is bonded to the second bonding portion, and the second bonding surface and the first bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and the center of the first bonding portion is aligned with the center of the second bonding portion in a direction perpendicular to the first substrate.

[0231] In some examples, the display device 30 can be an electronic device such as an optical projection, a vehicle-mounted head-up display (HUD), or any device with a display screen such as a smart phone, a smart watch, a laptop computer, a tablet computer, a driving recorder, a navigator, a head-mounted device, etc.

[0232] It should be noted that the display device provided in the embodiment of the present application, since it is equipped with the micro-light emitting diode device provided in the embodiment of the present application, can achieve the beneficial effects that can be achieved by any micro-light emitting diode device provided in the embodiment of the present application. Please see the previous embodiments for details, which will not be repeated here.

[0233] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for manufacturing a bonding structure, characterized in that: include: Providing a first substrate and a second substrate, wherein one side of the first substrate includes a first bonding surface and a first bonding portion, one side of the second substrate includes a second bonding surface and a second bonding portion, and the first bonding surface is provided with a first bonding groove; Bonding the first bonding surface to the second bonding surface to obtain a pre-bonded structure; Determine that the first bonding groove and the second bonding surface in the pre-bonding structure form a sealed cavity with an internal air pressure less than 1 standard atmosphere, and heat the first bonding part and / or the second bonding part in the pre-bonding structure to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, so that the first bonding part and the second bonding part are bonded to obtain a bonding structure.

2. The method according to claim 1, characterized in that One of the first bonding portion and the second bonding portion is a solder bump, and the other of the first bonding portion and the second bonding portion is a contact pad; The step of heating the first bonding portion and / or the second bonding portion in the pre-bonding structure to a molten state under an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, so as to bond the first bonding portion to the second bonding portion, to obtain a bonding structure, comprises: In an environment where the air pressure is less than or equal to the air pressure in the sealed cavity, heating the solder bump to a molten state so that the solder bump in the molten state wets the contact pad; The solder bump in a molten state is cooled to a solid state, and the solid solder bump is welded together with the contact pad to obtain a bonding structure.

3. The method according to claim 2, characterized in that The step of heating the solder bump to a molten state in an environment where the air pressure is less than or equal to the air pressure in the sealed cavity so that the solder bump in the molten state wets the contact pad comprises: The pre-bonded structure is placed in a reflow oven, and then the reflow oven is evacuated to a pressure of 1.3×10 -7 ~0.05MPa, and heating the solder bump to 150~350℃ to melt the solder bump, so that the solder bump in the molten state wets the contact pad, and the surface tension of the solder bump in the molten state pulls the contact pad to a position where the surface tension is balanced; The step of cooling the solder bump in a molten state to a solid state, wherein the solid solder bump is welded to the contact pad, comprises: The solder bump in the molten state is cooled to a temperature less than or equal to 60° C., so that the solder bump in the molten state is solidified, and the solid solder bump is welded together with the contact pad.

4. The method according to claim 1, characterized in that: Bonding the first bonding surface to the second bonding surface to obtain a pre-bonded structure comprises: The step of bonding the first bonding surface to the second bonding surface is performed until the first bonding groove of the first bonding surface and the second bonding surface form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, thereby obtaining a pre-bonded structure.

5. The method according to claim 1, characterized in that Bonding the first bonding surface to the second bonding surface comprises: In an environment where the air pressure is less than 1 standard atmospheric pressure, aligning and laminating the first bonding surface with the second bonding surface, and then applying pressure to the first substrate and / or the second substrate; The pressure was released.

6. The method according to claim 5, characterized in that The step of aligning and bonding the first bonding surface with the second bonding surface in an environment where the air pressure is less than 1 standard atmospheric pressure, and then applying pressure to the first substrate and / or the second substrate comprises: In an environment where the air pressure is less than or equal to 0.9 standard atmospheric pressure, aligning and laminating the first bonding surface with the second bonding surface, and then applying pressure to the first substrate and / or the second substrate; The releasing of the pressure comprises: In an environment where the air pressure is greater than or equal to 1 standard atmosphere, the pressure is released.

7. The method according to claim 1, characterized in that When the first bonding surface is in contact with the second bonding surface and the center of the first bonding surface coincides with the center of the second bonding surface, the first bonding portion overlaps with the second bonding portion, and the distance between the outer edge of the second bonding surface and the opening edge of the first bonding groove is smaller than the distance between the edge of the first side of the first bonding portion and the edge of the second side of the second bonding portion, wherein the first side and the second side are two sides opposite to each other in a direction parallel to the first substrate.

8. The method according to claim 1, characterized in that The first substrate is provided, comprising: Providing a first original substrate, wherein the first original substrate includes one or more semiconductor structures; Conductive material is deposited on the electrical interconnection area on the surface of the semiconductor structure of the first original substrate to form a first bonding block and a first bonding portion with a first bonding groove, wherein the first bonding block and the first bonding portion are used to electrically connect the semiconductor structure of the first original substrate with the second substrate.

9. The method according to claim 8, characterized in that The step of depositing a conductive material on the electrical interconnection region on the surface of the semiconductor structure of the first original substrate to form a first bonding block and a first bonding portion having a first bonding groove comprises: Metal material is deposited by magnetron sputtering on a first electrical interconnection region on the surface of the semiconductor structure of the first original substrate to form a first bonding block having a first bonding groove, and metal material is deposited on a second electrical interconnection region on the surface of the semiconductor structure of the first original substrate to form a first bonding portion.

10. The method according to any one of claims 1 to 9, characterized in that: The second bonding surface is provided with a second bonding groove; the first bonding groove and the second bonding surface in the pre-bonding structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, including: the first bonding groove and the second bonding groove in the pre-bonding structure form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure.

11. A bonding structure, characterized in that: include: A first substrate, one side of the first substrate comprising a first bonding surface and a first bonding portion, and the first bonding surface is provided with a first bonding groove; A second substrate, one side of the second substrate includes a second bonding surface and a second bonding portion, the second bonding surface is bonded to the first bonding surface, the second bonding portion is bonded to the first bonding portion, and the second bonding surface and the first bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, and the center of the first bonding portion is aligned with the center of the second bonding portion in a direction perpendicular to the first substrate.

12. The bonding structure according to claim 11, characterized in that: One of the first bonding portion and the second bonding portion is a solder bump, the other of the first bonding portion and the second bonding portion is a contact pad, and the solder bump wraps around a surface of the contact pad.

13. The bonding structure according to claim 11, characterized in that: When the first bonding surface is in contact with the second bonding surface and the center of the first bonding surface coincides with the center of the second bonding surface, the first bonding portion overlaps with the second bonding portion, and the distance between the outer edge of the second bonding surface and the opening edge of the first bonding groove is smaller than the distance between the edge of the first side of the first bonding portion and the edge of the second side of the second bonding portion, wherein the first side and the second side are two sides opposite to each other in a direction parallel to the first substrate.

14. The bonding structure according to claim 11, characterized in that: The first substrate includes a first original substrate, a first bonding block having a first bonding groove, and a first bonding portion, wherein the first original substrate includes one or more semiconductor structures, the first bonding block and the first bonding portion include conductive materials, and are respectively arranged on a first electrical interconnection area and a second electrical interconnection area on the surface of the semiconductor structure.

15. The bonding structure according to claim 14, characterized in that: The conductive material is a metal material.

16. The bonding structure according to claim 14, characterized in that: The first bonding groove penetrates the first bonding block.

17. The bonding structure according to any one of claims 11 to 16, characterized in that: The second bonding surface is provided with a second bonding groove; the second bonding surface and the first bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure, including: the first bonding groove and the second bonding groove form a sealed cavity with an internal air pressure less than 1 standard atmospheric pressure.

18. The bonding structure according to claim 17, characterized in that: The distance between the outer edge of the first bonding surface and the opening edge of the first bonding groove is greater than or less than the distance between the outer edge of the second bonding surface and the opening edge of the second bonding groove.

19. The bonding structure according to claim 17, characterized in that: The second substrate includes a second original substrate and a second bonding block, the second bonding block and the second bonding portion are arranged on one side of the second original substrate, and the second bonding surface is a surface of the second bonding block facing away from the second original substrate.

20. A micro light emitting diode device, characterized in that: A bonding structure prepared by the method described in any one of claims 1 to 10, or a bonding structure described in any one of claims 11-19.

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