Wafer bonding method and system

Abstract

The application discloses a wafer bonding method and system, the wafer bonding method comprises the following steps: setting a first bonding base on a first bearing, setting a second bonding base on a second bearing, the first bonding base has a first bonding surface, the second bonding base has a second bonding surface, and the first bonding surface and the second bonding surface are oppositely arranged; after aligning the first bonding base and the second bonding base in a first direction, obtaining first position information of the first bonding base and / or the second bonding base in a second direction perpendicular to the first direction; adjusting the position of the first bonding base and / or the second bonding base in the second direction based on the first position information, so that the distance between the first bonding base and the second bonding base in the second direction is a preset value; and bonding the first bonding base and the second bonding base. In the above manner, the distance between the two bonding surfaces before bonding can be stabilized by using the existing data acquisition assembly, and the bonding quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor, and in particular to a wafer bonding method and system. BACKGROUND

[0002] In the bonding process of semiconductor devices, the chip is generally bonded with the wafer through C2W bonding machine after the processes of temporary bonding, thinning, cutting, cleaning, etc. In the C2W bonding machine, the whole process is generally implemented through the processes of taking the chip, aligning and bonding. In the bonding process, the distance between the chip and the wafer is crucial to the bonding precision and quality, and therefore, it is crucial to maintain the stability of the distance between the bonding substrates before bonding for the stability of the process.

[0003] In order to solve this problem, the prior art measures the thickness difference of different chips and feeds back the distance between the chip and the wafer in the bonding process, so as to ensure the stability of the distance between the chip and the wafer before bonding. However, these methods need to increase additional components, thereby increasing the cost of the machine, which is not conducive to the maximization of benefits. SUMMARY

[0004] The technical problem solved by the present application is to provide a wafer bonding method and system, which can utilize the existing data recognition components to stabilize the distance between the two bonding surfaces before bonding and improve the bonding quality.

[0005] To solve the above technical problems, one technical solution adopted by the present application is to provide a wafer bonding method, which comprises: arranging a first bonding substrate on a first bearing member and arranging a second bonding substrate on a second bearing member, the first bonding substrate having a first bonding surface, the second bonding substrate having a second bonding surface, and the first bonding surface and the second bonding surface being oppositely arranged; after aligning the first bonding substrate and the second bonding substrate in a first direction, obtaining first position information of the first bonding substrate and / or the second bonding substrate in a second direction perpendicular to the first direction; adjusting the position of the first bonding substrate and / or the second bonding substrate in the second direction based on the first position information, so that the distance between the first bonding substrate and the second bonding substrate in the second direction is a preset value; and bonding the first bonding substrate and the second bonding substrate.

[0006] Further, the first position information comprises a first relative distance difference value of the first bonding surface and / or a second relative distance difference value of the second bonding surface; wherein the first relative distance difference value is a difference between a first relative distance between the first bonding surface and the second carrier in the second direction and a first initial relative distance; and the second relative distance difference value is a difference between a second relative distance between the second bonding surface and the first carrier in the second direction and a second initial relative distance.

[0007] Further, the first relative distance and / or the second relative distance are obtained by a visual recognition component.

[0008] Further, the adjusting the position of the first bonding substrate and / or the second bonding substrate in the second direction based on the first position information comprises: compensating the first relative distance difference value and / or the second relative distance difference value to a distance between the first carrier and the second bonding surface and / or a distance between the second carrier and the first bonding surface by adjusting the position of the first carrier relative to the second bonding surface in the second direction and / or adjusting the position of the second carrier relative to the first bonding surface in the second direction.

[0009] Further, the compensating the first relative distance difference value and / or the second relative distance difference value to a distance between the first carrier and the second bonding surface and / or a distance between the second carrier and the first bonding surface comprises: when the first relative distance difference value and / or the second relative distance difference value is not less than 0, moving the first carrier and / or the second carrier to a direction in which the first carrier and the second carrier are closer to each other by an absolute value of the first relative distance difference value and / or an absolute value of the second relative distance difference value; and / or, when the first relative distance difference value and / or the second relative distance difference value is less than 0, moving the first carrier and / or the second carrier to a direction in which the first carrier and the second carrier are farther away from each other by the absolute value of the first relative distance difference value and / or the absolute value of the second relative distance difference value.

[0010] Further, the first bonding substrate is at least two, and the second bonding substrate has at least two bonding regions with different thicknesses; when the at least two first bonding substrates are bonded to the at least two bonding regions with different thicknesses of the second bonding substrate respectively, the first relative distance difference value and / or the second relative distance difference value caused by a previous bonding process is compensated to a next bonding process.

[0011] Further, the preset value is 5-30um.

[0012] To solve the above technical problems, another technical solution adopted by the present application is to provide a wafer bonding system for implementing the wafer bonding method, the system comprising: a first bearing member and a second bearing member, the first bearing member facing one side of the second bearing member for bearing a first bonding substrate, the second bearing member facing one side of the first bearing member for bearing a second bonding substrate, the first bonding substrate having a first bonding surface, the second bonding substrate having a second bonding surface, and the first bonding surface and the second bonding surface being oppositely arranged; a data acquisition component for obtaining first position information of the first bonding substrate and / or the second bonding substrate in a second direction perpendicular to a first direction after the first bonding substrate and the second bonding substrate are aligned in the first direction; a driving component for adjusting the position of the first bearing member and / or the second bearing member in the second direction based on the first position information, so that the distance between the first bonding substrate and the second bonding substrate in the second direction is a preset value; a bonding component for bonding the first bonding substrate and the second bonding substrate.

[0013] Further, the first position information comprises a first relative distance difference value of the first bonding surface and / or a second relative distance difference value of the second bonding surface; wherein the first relative distance difference value is the difference between the first relative distance between the first bonding surface and the second bearing member in the second direction and a first initial relative distance; and the second relative distance difference value is the difference between the second relative distance between the second bonding surface and the first bearing member in the second direction and a second initial relative distance.

[0014] Further, the driving component is further configured to compensate the first relative distance difference value and / or the second relative distance difference value to the distance between the first bearing member and the second bonding surface and the distance between the second bearing member and the first bonding surface, respectively, by adjusting the position of the first bearing member relative to the second bonding surface in the second direction and / or adjusting the position of the second bearing member relative to the first bonding surface in the second direction.

[0015] Compared with the prior art, the wafer bonding method has the beneficial effects that: the wafer bonding method comprises the following steps: a first bonding substrate is arranged on a first bearing member, and a second bonding substrate is arranged on a second bearing member, the first bonding substrate has a first bonding surface, the second bonding substrate has a second bonding surface, and the first bonding surface and the second bonding surface are arranged oppositely; after the first bonding substrate and the second bonding substrate are aligned in a first direction, first position information of the first bonding substrate and / or the second bonding substrate in a second direction perpendicular to the first direction is obtained; the position of the first bonding substrate and / or the second bonding substrate in the second direction is adjusted based on the first position information, so that the distance between the first bonding substrate and the second bonding substrate in the second direction is a preset value; and the first bonding substrate and the second bonding substrate are bonded. In this way, the existing data acquisition assembly can be used to realize bonding position alignment and control the distance between the bonding surfaces of the two bonding substrates, so that the distance between the bonding surfaces of the two bonding substrates is constant before bonding, the optimal bonding distance between the bonded bonding substrates is ensured, the bonding precision and quality are improved, no additional components are needed, and the equipment cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0017] Figure 1 is a flowchart of an embodiment of the wafer bonding method of the present application;

[0018] Figure 2 is a structural schematic diagram of an embodiment of the wafer bonding method of the present application;

[0019] Figure 3 is a structural schematic diagram of another embodiment of the wafer bonding method of the present application;

[0020] Figure 4 is a structural schematic diagram of an embodiment of the wafer bonding system of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] Please refer toFigures 1-2 , Figure 1 Figure 1 is a flow diagram of an embodiment of a wafer bonding method according to the present application, Figure 2 Figure 2 is a schematic diagram of an embodiment of a wafer bonding method according to the present application, which can comprise the following steps S101-S104.

[0023] S101: disposing a first bonding substrate 1 on a first carrier 41 and a second bonding substrate 2 on a second carrier 42, the first bonding substrate 1 having a first bonding surface a1 and the second bonding substrate 2 having a second bonding surface a2, and the first bonding surface a1 and the second bonding surface a2 being oppositely disposed.

[0024] The first carrier 41 is configured to carry the first bonding substrate 1 on a side of the first carrier 41 facing the second carrier 42, and the second carrier 42 is configured to carry the second bonding substrate 2 on a side of the second carrier 42 facing the first carrier 41. In an embodiment, the first carrier 41 can comprise, but is not limited to, a suction member configured to suck a side surface of the first bonding substrate 1 away from the first bonding surface a1, and the second carrier 42 can comprise, but is not limited to, a base configured to place the second bonding substrate 2 on a side surface of the base close to the second bonding substrate 2.

[0025] The first bonding substrate 1 and the second bonding substrate 2 used in the wafer bonding method according to some embodiments of the present application can be any bonding substrate known in the art. The first bonding substrate 1 and / or the second bonding substrate 2 can comprise, but are not limited to, a single-crystal, a polycrystalline or an amorphous structure of silicon material used in semiconductor applications. The first bonding substrate 1 can be the same as or different from the second bonding substrate 2 in size, thickness, material or structure. Preferably, the size of the second bonding substrate 2 can be much larger than that of the first bonding substrate 1. In the following embodiments of the present application, the first bonding substrate 1 is taken as a chip and the second bonding substrate 2 is taken as a wafer for illustration. Of course, in other embodiments, the first bonding substrate 1 can be a chip or a wafer, and the second bonding substrate 2 can be a chip or a wafer, which are not limited in particular.

[0026] S102: after aligning the first bonding substrate 1 and the second bonding substrate 2 in a first direction D1, obtaining first position information of the first bonding substrate 1 and / or the second bonding substrate 2 in a second direction D2 perpendicular to the first direction D1.

[0027] In an embodiment, the first direction D1 can be a horizontal direction, and the second direction D2 perpendicular to the first direction D1 can be a vertical direction, which are not limited in particular. Aligning the first bonding substrate 1 and the second bonding substrate 2 in the first direction D1 means that the first bonding substrate 1 and the second bonding substrate 2 satisfy the bonding alignment requirement in the first direction D1.

[0028] The first position information includes a first relative distance difference value Δn1 (not shown) of the first bonding surface a1, and / or a second relative distance difference value Δn2 (not shown) of the second bonding surface a2; wherein the first relative distance difference value Δn1 is a difference between a first relative distance n1 between the first bonding surface a1 and the second carrier 42 in the second direction D2 and a first initial relative distance n01 (not shown); and the second relative distance difference value Δn2 is a difference between a second relative distance n2 between the second bonding surface a2 and the first carrier 41 in the second direction D2 and a second initial relative distance n02 (not shown). The first initial relative distance n01 is a first relative distance between the first bonding surface a1 of the first bonding substrate 1 and the second carrier 42 when the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 is a preset value; and the second initial relative distance n02 is a second relative distance between the second bonding surface a2 of the second bonding substrate 2 and the first carrier 41 when the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 is the preset value. In this way, before each bonding, the positions of the first bonding surface a1 and the second bonding surface a2 in the second direction D2 can be adjusted according to the first relative distance difference value and / or the second relative distance difference value, so that the distance between the first bonding surface a1 and the second bonding surface a2 can be stabilized at the preset value during each bonding, thereby ensuring the uniformity of the bonding strength of the first bonding substrate 1 and the second bonding substrate 2. In some embodiments of the present application, the first relative distance n1 and the first initial relative distance n01, and the second relative distance n2 and the second initial relative distance n02 are relatively uniform for each corresponding reference point for distance measurement in the same coordinate system.

[0029] In an embodiment, the preset value can be the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 in a group of bonding substrates in which the first bonding substrate 1 and the second bonding substrate 2 are bonded first; in another embodiment, the preset value can also be the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 when the first bonding surface a1 and the second bonding surface a2 are at the optimal bonding distance. Preferably, the preset value can be 5-30um (such as 5um, 10um, 15um, 20um, 25um and 30um, etc.), and in this range, the bonding strength between the first bonding surface a1 and the second bonding surface a2 is higher, and this range can be determined according to the optimal bonding distance of the actual first bonding substrate 1 and the second bonding substrate 2.

[0030] In an embodiment, the first relative distance n1 and / or the second relative distance n2 can be obtained by the visual recognition component 3. The existing visual recognition component 3 can be reused as a data acquisition component for acquiring the position data of the first bonding surface a1 and the second bonding surface a2 in the second direction D2, which reduces the design cost and equipment cost caused by the additional data acquisition component. Of course, in other embodiments, other data acquisition components can also be used to acquire the position data of the first bonding surface a1 and the second bonding surface a2 in the second direction D2, such as a laser ranging component.

[0031] Please refer to Figure 2 The visual recognition component 3 can include a first recognition part 31 for recognizing the first bonding surface a1 and / or a second recognition part 32 for recognizing the second bonding surface a2. The first recognition part 31 is located on the side of the second bonding substrate 2 away from the first bonding substrate 1, and the second recognition part 32 is located on the side of the first bonding substrate 1 away from the second bonding substrate 2. The first relative distance n1 between the first bonding surface a1 of the first bonding substrate 1 and the second carrier 42 in the second direction D2 can be obtained by focusing the first alignment mark m1 of the first bonding surface a1 by the first recognition part 31 of the visual recognition component 3, and the first relative distance difference Δn1 of the first bonding surface a1 can be obtained according to the difference between the first relative distance n1 and the first initial relative distance n01, where Δn1 = n1 - n01; and / or the second relative distance n2 between the second bonding surface a2 of the second bonding substrate 2 and the first carrier 41 in the second direction D2 can be obtained by focusing the second alignment mark m2 of the second bonding surface a2 by the second recognition part 32 of the visual recognition component 3, and the second relative distance difference Δn2 of the second bonding surface a2 can be obtained according to the difference between the second relative distance n2 and the second initial relative distance n02, where Δn2 = n2 - n02. The first alignment mark m1 and the second alignment mark m2 are visible patterns that can be recognized by the visual recognition component 3, and can be one or more line grooves for marking the position and direction of the first bonding substrate 1 and the second bonding substrate 2.

[0032] S103: Adjust the position of the first bonding substrate 1 and / or the second bonding substrate 2 in the second direction D2 based on the first position information, so that the distance between the first bonding substrate 1 and the second bonding substrate 2 in the second direction D2 is a preset value.

[0033] In an embodiment, the step can comprise: compensating the first relative distance difference Δn1 and / or the second relative distance difference Δn2 to the distance between the first carrier 41 and the second bonding surface a2 and / or the distance between the second carrier 42 and the first bonding surface a1, respectively, by adjusting the position of the first carrier 41 relative to the second bonding surface a2 in the second direction D2 and / or adjusting the position of the second carrier 42 relative to the first bonding surface a1 in the second direction D2, so that the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction is a preset value. In this way, before each bonding, the position of the first bonding surface a1 and the second bonding surface a2 in the second direction D2 can be adjusted according to the first relative distance difference and / or the second relative distance difference, respectively, so that the distance between the first bonding surface a1 and the second bonding surface a2 can be stabilized at a preset value during each bonding, thereby ensuring the uniformity of the bonding strength of the first bonding substrate 1 and the second bonding substrate 2.

[0034] Wherein, compensating the first relative distance difference Δn1 and / or the second relative distance difference Δn2 to the distance between the first carrier 41 and the second bonding surface a2 and / or the distance between the second carrier 42 and the first bonding surface a1 can comprise but is not limited to: when the first relative distance difference Δn1 and / or the second relative distance difference Δn2 is not less than 0, moving the first carrier 41 and / or the second carrier 42 in the direction in which the first carrier 41 and the second carrier 42 approach each other by the absolute value of the first relative distance difference Δn1 and / or the absolute value of the second relative distance difference Δn2; and / or, when the first relative distance difference Δn1 and / or the second relative distance difference Δn2 is less than 0, moving the first carrier 41 and / or the second carrier 42 in the direction in which the first carrier 41 and the second carrier 42 move away from each other by the absolute value of the first relative distance difference Δn1 and / or the absolute value of the second relative distance difference Δn2. In this way, when the bonding distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 is too far or too close, the bonding distance can be reduced or expanded to a preset value by adjusting the position of the first bonding substrate 1 and / or the second bonding substrate 2 in the second direction D2, thereby reducing the difference in bonding distance and improving the uniformity of the bonding strength.

[0035] For example, in an embodiment, when Δn1≥0, the first carrier 41 can be moved |Δn1| distance towards the second carrier 42; when Δn1<0, the first carrier 41 can be moved |Δn1| distance away from the second carrier 42; when Δn2≥0, the second carrier 42 can be moved |Δn2| distance towards the first carrier 41; when Δn2<0, the second carrier 42 can be moved |Δn2| distance away from the first carrier 41.

[0036] In other embodiments, when Δn1≥0 and Δn2≥0, the first carrier 41 can be moved by a distance of |Δn1| towards the second carrier 42, while the second carrier 42 can be moved by a distance of |Δn2| towards the first carrier 41; or the first carrier 41 can be moved by a distance of |Δn1| away from the second carrier 42, while the second carrier 42 can be moved by a distance of |Δn2|+2|Δn1| towards the first carrier 41; or the second carrier 42 can be moved by a distance of |Δn2| away from the first carrier 41, while the first carrier 41 can be moved by a distance of |Δn1|+2|Δn2| towards the second carrier 42; when Δn1≥0 and Δn2<0, the first carrier 41 can be moved by a distance of |Δn1| towards the second carrier 42, while the second carrier 42 can be moved by a distance of |Δn2| away from the first carrier 41; or the first carrier 41 can be moved by a distance of |Δn1| away from the second carrier 42, while the second carrier 42 can be moved by a distance of ||Δn2|-2|Δn1|| away from the first carrier 41; or the second carrier 42 can be moved by a distance of |Δn2| towards the first carrier 41, while the first carrier 41 can be moved by a distance of |2|Δn2|-|Δn1|| away from the second carrier 42. Similarly, when Δn1<0 and Δn2≥0, when Δn1<0 and Δn2<0, the same can be applied.

[0037] As to whether the first carrier 41 and the second carrier 42 are moved towards or away from each other, and how much distance is moved, it can be set as needed.

[0038] As to the implementation of compensating the first relative distance difference Δn1 and / or the second relative distance difference Δn2 to the distance between the first carrier 41 and the second bonding surface a2, and the distance between the second carrier 42 and the first bonding surface a1, by adjusting the position of the first carrier 41 relative to the second bonding surface a2 in the second direction D2 and / or adjusting the position of the second carrier 42 relative to the first bonding surface a1 in the second direction D2, there can be many ways, and the following explains the various embodiments of this step in detail.

[0039] In an embodiment, the first relative distance difference Δn1 can be compensated to the distance between the first carrier 41 and the second bonding surface a2 to make the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 a preset value by adjusting the position of the first carrier 41 relative to the second bonding surface a2 in the second direction D2. For example, before the first bonding substrate 1 is bonded to the second bonding substrate 2, the first recognition component 31 of the visual recognition assembly 3 is used to obtain the first relative distance n1 between the first bonding surface a1 of the first bonding substrate 1 and the second carrier 42, and the first relative distance n1 is different from the first initial relative distance n01, i.e., the first relative distance difference Δn1 = n1 - n01. The first carrier 41 is moved towards or away from the second carrier 42 in the second direction D2 by a distance of |Δn1|, and the first relative distance difference Δn1 = n1 - n01 is compensated to the distance between the first carrier 41 and the second bonding surface a2 to make the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 a preset value. Through the first relative distance difference Δn1, the thickness difference between different first bonding substrates 1 can be obtained, so that the thickness difference between different first bonding substrates 1 can be compensated by moving the first carrier 41 to adjust the distance between the first carrier 41 and the second bonding surface a2 through the existing data acquisition assembly, without increasing additional components (such as an infrared distance meter, a pressure sensor, etc.) and increasing the cost of the device. The distance between the first bonding surface a1 and the second bonding surface a2 can be stabilized, and the alignment accuracy of the first bonding substrate 1 and the second bonding substrate 2 can be improved.

[0040] Of course, in another embodiment, the second relative distance difference An2 can also be compensated to the distance between the second carrier 42 and the first bonding surface a1 to make the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 a preset value by adjusting the position of the second carrier 42 relative to the first bonding surface a1 in the second direction D2. For example, before bonding the second bonding substrate 2 to the first bonding substrate 1, the second identification component 32 of the visual identification assembly 3 is used to obtain the second relative distance n2 between the second bonding surface a2 of the second bonding substrate 2 and the first carrier 41, and the second relative distance difference An2 = n2 - n02 between the second bonding substrate 2 and the second initial relative distance n02, and the second carrier 42 is moved by a distance of |An2| relative to the first bonding surface a1 in the second direction D2, away from or towards the first carrier 41, to compensate the second relative distance difference An2 = n2 - n02 to the distance between the second carrier 42 and the first bonding surface a1 to make the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 a preset value. Through the second relative distance difference An2, the thickness difference between different second bonding substrates 2 can be obtained, so that the thickness difference between different second bonding substrates 2 can be compensated by moving the second carrier 42 to adjust the distance between the second carrier 42 and the first bonding surface a1 through the existing data acquisition assembly, without increasing additional components (such as an infrared distance meter, a pressure sensor, etc.) and increasing the cost of the equipment, so as to maintain the stability of the distance between the first bonding surface a1 and the second bonding surface a2 and improve the alignment accuracy of the first bonding substrate 1 and the second bonding substrate 2.

[0041] In other embodiments, in the case where the thicknesses of the first bonding substrate 1 and the second bonding substrate 2 both change, the first relative distance difference An1 and / or the second relative distance difference An2 are respectively compensated to the distance between the first carrier 41 and the second bonding surface a2 and the distance between the second carrier 42 and the first bonding surface a1 to make the distance between the first bonding surface a1 and the second bonding surface a2 in the second direction D2 a preset value by adjusting the position of the first carrier 41 relative to the second bonding surface a2 in the second direction D2 and adjusting the position of the second carrier 42 relative to the first bonding surface a1 in the second direction D2.

[0042] Further, the first bonding substrate 1 can be at least two, and the second bonding substrate 2 can have at least two bonding regions with different thicknesses; when the at least two first bonding substrates 1 are bonded to the at least two bonding regions with different thicknesses of the second bonding substrate 2 respectively, the first relative distance difference and / or the second relative distance difference caused by the previous bonding process is compensated to the next bonding process. In this way, when the second bonding surface a2 is not flat, the distance between the first bonding surface a1 and each bonding region on the second bonding surface a2 before bonding can also be stabilized at a preset value, thereby ensuring the uniformity of the bonding strength.

[0043] Please refer to Figure 3 , Figure 3 is a structural schematic diagram of another embodiment of the wafer bonding method of the present application. When two first bonding substrates H and K are bonded to positions X and Y of the second bonding substrate 2 respectively, the first recognition member 31 of the visual recognition assembly 3 is used to obtain the first relative distance nH between the first bonding surface aH of the first bonding substrate H and the second carrier 42, and the first relative distance difference AH = nH - n01 of the first bonding substrate H is obtained according to the difference between the first relative distance nH and the first initial relative distance n01. The first recognition member 31 of the visual recognition assembly 3 can be used to obtain the first relative distance nk between the first bonding surface aK of the first bonding substrate K and the second carrier 42, and the first relative distance difference AK = nK - n01 of the first bonding substrate K is obtained according to the difference between the first relative distance nK and the first initial relative distance n01. The second recognition member 32 of the visual recognition assembly 3 can be used to obtain the second relative distance nX between the first bonding surface aX of the second bonding substrate position X and the first carrier 41, and the second relative distance difference AX = nX - n02 of the second bonding substrate position X is obtained according to the difference between the second relative distance nX and the second initial relative distance n02. The second recognition member 32 of the visual recognition assembly 3 can be used to obtain the first relative distance nY between the first bonding surface aY of the second bonding substrate position Y and the first carrier 41, and the second relative distance difference AY = nY - n02 of the second bonding substrate position Y is obtained according to the difference between the second relative distance nY and the second initial relative distance n02. Assuming that the bonding of the first bonding substrate H to the second surface aX and the bonding of the second bonding substrate K to the second surface aY are two adjacent bonding processes, and AH = nH - n01 < 0; AX = nX - n02 > 0; AK = nK - n01 > 0; AY = nY - n02 < 0, then:

[0044] When the previous bonding process is performed, i.e. when the first bonding substrate H is bonded to the second bonding substrate 2 at the position X: the first carrier 41 can be moved away from the second carrier 42 by a distance of |△nH| in the second direction D2 relative to the second bonding surface a2, and the second carrier 42 can be moved towards the first carrier 41 by a distance of |△nX| in the second direction D2 relative to the first bonding surface a1.

[0045] Before the next bonding process is performed, i.e. before the first bonding substrate K is bonded to the second bonding substrate 2 at the position Y, the first relative distance difference and / or the second relative distance difference caused by the previous bonding process need to be compensated for the next bonding process: the first carrier 41 can be moved towards the second carrier 42 by a distance of |△nH+|△nK| in the second direction D2 relative to the second bonding surface a2, and the second carrier 42 can be moved away from the first carrier 41 by a distance of |△nX+|△nY| in the second direction D2 relative to the first bonding surface a1.

[0046] S104: Bond the first bonding substrate 1 and the second bonding substrate 2. The bonding can be directly performed, or the first bonding surface a1 and / or the second bonding surface a2 can be surface treated before the bonding, or a bonding chemical reagent can be applied to perform the bonding. The selection can be made according to actual process requirements.

[0047] By the above steps S101-S104, the existing data acquisition assembly can be used to realize the alignment of the bonding position and the regulation of the distance between the bonding surfaces of the two bonding substrates, so that the distance between the bonding surfaces of the two bonding substrates is constant before the bonding, the optimal bonding distance between the bonded bonding substrates is ensured, the bonding precision and quality are improved, no additional components are needed, and the equipment cost is reduced. In this way, the bonding distance between the first bonding substrate and the second bonding substrate can be accurately controlled, and the stability of the bonding is improved.

[0048] The application also provides a wafer bonding system, which will be described below with reference to Figures 2-4 , Figure 4 FIG. 1 is a structural schematic diagram of an embodiment of the wafer bonding system of the application. The system comprises a data acquisition assembly, a first carrier 41 and a second carrier 42, a driving assembly 5, and a bonding assembly 6.

[0049] The first carrier 41 is used to carry the first bonding substrate 1, and the second carrier 42 is used to carry the second bonding substrate 2. The side of the first carrier 41 facing the second carrier 42 is used to carry the first bonding substrate 1, and the side of the second carrier 42 facing the first carrier 41 is used to carry the second bonding substrate 2. The first bonding substrate 1 has a first bonding surface a1, and the second bonding substrate 2 has a second bonding surface a2. The first bonding surface a1 and the second bonding surface a2 are oppositely arranged.

[0050] a data acquisition component configured to obtain first position information of the first bonding substrate 1 and / or the second bonding substrate 2 in a second direction D2 perpendicular to the first direction D1 after the first bonding substrate 1 and the second bonding substrate 2 are aligned in the first direction D1. In an embodiment, the data acquisition component can be the visual recognition component 3. In an embodiment, the first position information can include a first relative distance difference value of the first bonding surface a1 and / or a second relative distance difference value of the second bonding surface a2; wherein the first relative distance difference value is a difference between a first relative distance n1 between the first bonding surface a1 and the second carrier 42 in the second direction D2 and a first initial relative distance n01; and the second relative distance difference value is a difference between a second relative distance n2 between the second bonding surface a2 and the first carrier 41 in the second direction D2 and a second initial relative distance n02. In this way, the positions of the first bonding surface a1 and the second bonding surface a2 in the second direction D2 can be adjusted according to the first relative distance difference value and / or the second relative distance difference value respectively before each bonding, so that the distance between the first bonding surface a1 and the second bonding surface a2 can be stabilized at a preset value during each bonding, thereby ensuring the uniformity of the bonding strength of the first bonding substrate 1 and the second bonding substrate 2.

[0051] a driving component 5 configured to adjust the positions of the first carrier 41 and / or the second carrier 42 in the second direction D2 based on the first position information, so that the distance between the first bonding substrate 1 and the second bonding substrate 2 in the second direction D2 is a preset value. The preset value can be 5-30um (e.g. 5um, 10um, 15um, 20um, 25um and 30um, etc.), which can be determined according to the optimal bonding distance of the actual first bonding substrate 1 and the second bonding substrate 2. In an embodiment, the driving component 5 can also be configured to compensate the first relative distance difference value and / or the second relative distance difference value to the distance between the first carrier 41 and the second bonding surface a2 and / or the distance between the second carrier 42 and the first bonding surface a1 by adjusting the position of the first carrier 41 relative to the second bonding surface a2 in the second direction D2 and / or adjusting the position of the second carrier 42 relative to the first bonding surface in the second direction D2. In this way, the positions of the first bonding surface a1 and the second bonding surface a2 in the second direction D2 can be adjusted according to the first relative distance difference value and / or the second relative distance difference value respectively before each bonding, so that the distance between the first bonding surface a1 and the second bonding surface a2 can be stabilized at a preset value during each bonding, thereby ensuring the uniformity of the bonding strength of the first bonding substrate 1 and the second bonding substrate 2.

[0052] a bonding component 6 configured to bond the first bonding substrate 1 and the second bonding substrate 2.

[0053] Through the system, the existing data acquisition component can be used to realize the alignment of the bonding position and the regulation of the distance between the bonding surfaces of the two bonding substrates, so that the bonding surfaces of the two bonding substrates have a constant distance before bonding, the optimal bonding distance between the bonded bonding substrates is ensured, the bonding precision and quality are improved, no additional components are needed, and the equipment cost is reduced.

[0054] As can be seen, the wafer bonding method adopted by the present application comprises: arranging a first bonding substrate on a first bearing member and a second bonding substrate on a second bearing member, the first bonding substrate has a first bonding surface, the second bonding substrate has a second bonding surface, and the first bonding surface and the second bonding surface are oppositely arranged; after aligning the first bonding substrate and the second bonding substrate in a first direction, obtaining first position information of the first bonding substrate and / or the second bonding substrate in a second direction perpendicular to the first direction; adjusting the position of the first bonding substrate and / or the second bonding substrate in the second direction based on the first position information, so that the distance between the first bonding substrate and the second bonding substrate in the second direction is a preset value; and bonding the first bonding substrate and the second bonding substrate. Through the above method, the existing data acquisition component can be used to realize the alignment of the bonding position and the regulation of the distance between the bonding surfaces of the two bonding substrates, so that the bonding surfaces of the two bonding substrates have a constant distance before bonding, the optimal bonding distance between the bonded bonding substrates is ensured, the bonding precision and quality are improved, no additional components are needed, and the equipment cost is reduced.

[0055] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A wafer bonding method, characterized by, The method comprises: arranging a first bonding base on a first carrier and a second bonding base on a second carrier, the first bonding base having a first bonding surface, the second bonding base having a second bonding surface, and the first bonding surface and the second bonding surface being oppositely arranged; after aligning the first bonding base and the second bonding base in a first direction, obtaining first position information of the first bonding base and / or the second bonding base in a second direction perpendicular to the first direction; adjusting the position of the first bonding base and / or the second bonding base in the second direction based on the first position information, so that the distance between the first bonding base and the second bonding base in the second direction is a preset value; bonding the first bonding base and the second bonding base; the first position information comprises a first relative distance difference value of the first bonding surface and / or a second relative distance difference value of the second bonding surface; wherein the first relative distance difference value is the difference between a first relative distance between the first bonding surface and the second carrier in the second direction and a first initial relative distance; the second relative distance difference value is the difference between a second relative distance between the second bonding surface and the first carrier in the second direction and a second initial relative distance; the first initial relative distance is the first relative distance between the first bonding surface of the first bonding base and the second carrier when the distance between the first bonding surface and the second bonding surface in the second direction is the preset value; the second initial relative distance is the second relative distance between the second bonding surface of the second bonding base and the first carrier when the distance between the first bonding surface and the second bonding surface in the second direction is the preset value.

2. The method of claim 1, wherein, The first relative distance and / or the second relative distance are obtained by a visual recognition component.

3. The method of claim 1, wherein: the step of adjusting the position of the first bonding base and / or the second bonding base in the second direction based on the first position information comprises: compensating the first relative distance difference value and / or the second relative distance difference value to the distance between the first carrier and the second bonding surface and the distance between the second carrier and the first bonding surface, respectively, by adjusting the position of the first carrier relative to the second bonding surface in the second direction and / or adjusting the position of the second carrier relative to the first bonding surface in the second direction.

4. The method of claim 3, wherein: the step of compensating the first relative distance difference value and / or the second relative distance difference value to the distance between the first carrier and the second bonding surface and the distance between the second carrier and the first bonding surface, respectively, comprises: When the first relative distance difference and / or the second relative distance difference is not less than 0, moving the first carrier and / or the second carrier by the absolute value of the first relative distance difference and / or the second relative distance difference in the direction in which the first carrier and the second carrier are closer to each other; and / or, when the first relative distance difference and / or the second relative distance difference is less than 0, moving the first carrier and / or the second carrier by the absolute value of the first relative distance difference and / or the second relative distance difference in the direction in which the first carrier and the second carrier are farther away from each other.

5. The method of claim 3, wherein, the first bonding substrate is at least two, and the second bonding substrate has at least two bonding regions with different thicknesses; and the first relative distance difference and / or the second relative distance difference caused by a previous bonding process is compensated to a next bonding process when the at least two first bonding substrates are bonded to the at least two bonding regions with different thicknesses of the second bonding substrate respectively.

6. The method of claim 1, wherein, the preset value is 5-30um.

7. A wafer bonding system, characterized by, comprising: a first carrier and a second carrier, the first carrier is used to carry a first bonding substrate on a side facing the second carrier, and the second carrier is used to carry a second bonding substrate on a side facing the first carrier, the first bonding substrate has a first bonding surface, the second bonding substrate has a second bonding surface, and the first bonding surface and the second bonding surface are oppositely arranged; a data acquisition component, configured to obtain first position information of the first bonding substrate and / or the second bonding substrate in a second direction perpendicular to a first direction after the first bonding substrate and the second bonding substrate are aligned in the first direction; a driving component, configured to adjust a position of the first carrier and / or the second carrier in the second direction based on the first position information, so that a distance between the first bonding substrate and the second bonding substrate in the second direction is a preset value; a bonding component, configured to bond the first bonding substrate and the second bonding substrate; the first position information comprises a first relative distance difference of the first bonding surface and / or a second relative distance difference of the second bonding surface; and the first bonding substrate is at least two, and the second bonding substrate has at least two bonding regions with different thicknesses; and the first relative distance difference and / or the second relative distance difference caused by a previous bonding process is compensated to a next bonding process when the at least two first bonding substrates are bonded to the at least two bonding regions with different thicknesses of the second bonding substrate respectively. The first relative distance difference value is a difference between a first relative distance between the first bonding surface and the second carrier in the second direction and a first initial relative distance; the second relative distance difference value is a difference between a second relative distance between the second bonding surface and the first carrier in the second direction and a second initial relative distance; the first initial relative distance is a first relative distance between the first bonding surface of the first bonding substrate and the second carrier when a distance between the first bonding surface and the second bonding surface in the second direction is the preset value; and the second initial relative distance is a second relative distance between the second bonding surface of the second bonding substrate and the first carrier when the distance between the first bonding surface and the second bonding surface in the second direction is the preset value.

8. The system of claim 7, wherein, The driving assembly is further configured to compensate the first relative distance difference value and / or the second relative distance difference value to a distance between the first carrier and the second bonding surface and / or a distance between the second carrier and the first bonding surface, by adjusting a position of the first carrier relative to the second bonding surface in the second direction and / or adjusting a position of the second carrier relative to the first bonding surface in the second direction.

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