Wafer bonding apparatus and wafer bonding method

Abstract

The application discloses a wafer bonding device and a wafer bonding method, and belongs to the technical field of wafer processing, which comprises a plurality of visual components based on infrared detection, and the combination of two displacement mechanisms and the preferred design of a bonding component are used, so that the same visual component can simultaneously realize the simultaneous imaging of two metal marks on the same infrared camera on the to-be-pasted chip and the target chip, the relative position relationship between the to-be-pasted chip and the target chip is accurately obtained through the simultaneous detection of a plurality of visual components on a plurality of groups of mark points, and the fast and accurate alignment of the target chip and the to-be-pasted chip before bonding is completed based on the relative position relationship. The wafer bonding device has the advantages of compact structure, convenient use, fast alignment before chip bonding, avoidance of frequent alignment and correction processes of a plurality of positioning components, guarantee of the alignment accuracy of the to-be-pasted chip and the target chip before bonding, improvement of the quality of chip bonding processing, and reduction of the defective rate of chip processing.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wafer processing, and particularly relates to a wafer bonding device and a wafer bonding method. BACKGROUND

[0002] Bonding technology is a technology for closely combining two pieces of homogeneous or heterogeneous wafers through van der Waals force to realize electrical interconnection, functional integration and device packaging of microelectronic materials, optoelectronic materials and nanomaterials, etc. The devices made by the bonding technology often have the advantages of direct metal interconnection, less heat generation, low power consumption, short delay, etc., and thus have a wide application in the fields of radio frequency devices, inertial devices, optoelectronic devices, information processing device preparation and 3D integrated logic integrated circuit packaging, etc.

[0003] Bonding technology is widely used in the field of wafer processing and plays a very important role in the process of chip bonding. In the process of wafer bonding, the objects to be bonded need to be accurately aligned to ensure the accuracy of chip bonding processing. At present, for the alignment in the process of wafer bonding, a separate alignment assembly is usually needed to be set, and the alignment assembly is used to complete the alignment operation first, and then the bonding assembly is controlled to move to the position according to the alignment result, and then the bonding process is completed. Although this method can meet the demand of alignment before bonding to a certain extent, both the alignment assembly and the bonding assembly need to be subjected to additional mechanical displacement process before bonding, which is easy to introduce new alignment error. Moreover, the above method is greatly affected by temperature and vibration, and when the working environment changes, the accuracy of bonding alignment will also be affected, resulting in fluctuations in the accuracy of bonding processing, which has obvious limitations. SUMMARY

[0004] In view of one or more of the above defects or improvement needs of the prior art, the present application provides a wafer bonding device and a wafer bonding method, which can accurately realize the accurate alignment of target chips on a wafer and chips to be bonded before bonding, ensure the quality of wafer bonding, improve the quality of chip bonding processing, and reduce the defective rate of products.

[0005] To achieve the above purpose, the present application provides a wafer bonding device and a wafer bonding method, which comprises:

[0006] A bonding assembly comprising a bonding head for taking the chip to be bonded, the bonding head being connected to a plane adjustment module, the plane adjustment module being used to drive the bonding head to perform XYθ adjustment in the plane;

[0007] A bonding table for carrying target chips to be aligned and bonded with the chip to be bonded;

[0008] The first displacement mechanism and the second displacement mechanism; the planar adjustment module is assembled on the second displacement mechanism, and the bonding head is driven by the second displacement mechanism to approach or move away from the bonding table; the second displacement mechanism is assembled on the first displacement mechanism and can be horizontally displaced under the driving of the first displacement mechanism;

[0009] At least two visual components, the visual component includes an infrared camera module, the infrared camera module has an infrared light source for emitting infrared light and an infrared camera for focusing imaging of the infrared light; the light path of the infrared light emitted from the visual component lens is perpendicular to the mutually parallel to-be-tested chip and the target chip; and

[0010] The lens corresponding to each visual component on the bonding head is respectively provided with an alignment through hole; the infrared light emitted from each visual component lens is respectively emitted to a first mark point on the to-be-tested chip and a second mark point on the target chip after penetrating the alignment through hole and the to-be-tested chip; both mark points are metal Marks, and the infrared light forms two detection light paths after irradiating the two metal Marks; and a glass lens is arranged in the alignment through hole, and the detection light path of the first mark point is simultaneously imaged with another detection light path not penetrating the glass lens on the infrared camera after penetrating the glass lens; the glass lens satisfies:

[0011] d =H1 / ( n -1)

[0012] In the formula, d H is the thickness of the glass lens; H1 is the distance between the target chip and the to-be-tested chip in the light path direction; n n is the refractive index of the glass lens.

[0013] As a further improvement of the present application, the spectral range of the infrared light is between 1100nm and 1345nm.

[0014] As a further improvement of the present application, each displacement mechanism includes a guide rail and a motor assembled on the guide rail; and the guide rail of the second displacement mechanism is connected with the motor of the first displacement mechanism and can follow the horizontal displacement thereof; and the planar adjustment module is connected with the motor of the second displacement mechanism and can follow the vertical displacement thereof.

[0015] As a further improvement of the present application, a fixed plate is connected and arranged on the motor of the first displacement mechanism, and the at least two visual components and the guide rail of the second displacement mechanism are simultaneously mounted on the fixed plate.

[0016] As a further improvement of the present application, the visual components are two components separately arranged on both sides of the bonding assembly for detecting the mark points at both ends of the to-be-tested chip.

[0017] And / or

[0018] The glass lens is arranged with a size not greater than half of the cross-sectional area of the alignment through hole.

[0019] As a further improvement of the application, the bottom surface of the bonding head is a working surface, and a plurality of negative pressure adsorption holes are arranged on the working surface, and the adsorption and taking of the chip to be attached are realized by means of negative pressure adsorption.

[0020] As a further improvement of the application, the infrared camera module in the visual assembly is arranged in a staggered manner with the lens of the visual assembly, and a mirror group is arranged between the infrared camera module and the lens; the mirror group comprises at least one mirror.

[0021] As a further improvement of the application, the mirror group comprises a first mirror and a second mirror arranged in a staggered manner in the horizontal direction.

[0022] The two mirrors are arranged at an angle of 45° with the horizontal plane, for vertically reflecting the detection light path from the infrared camera module to be horizontal, and finally vertically reflecting the detection light path again.

[0023] Another aspect of the application also provides a wafer bonding method, which utilizes the wafer bonding device to achieve, and comprises the following processes:

[0024] (1) controlling the bonding head to complete the taking of the chip to be attached;

[0025] (2) controlling the first displacement mechanism to move, so as to drive the bonding head above the corresponding target chip;

[0026] (3) controlling the visual assemblies to work respectively, so as to respectively perform infrared focusing imaging on the pairs of first mark points and second mark points by the visual assemblies, and obtain imaging information of multiple groups of mark points;

[0027] (4) processing the imaging information of multiple groups of mark points, obtaining the relative position relationship between the two chips, and obtaining the XYθ adjustment information of the chip to be attached; thereafter, controlling the planar adjustment module to work, so as to accurately align the chip to be attached with the target chip;

[0028] (5) controlling the second displacement mechanism to work, so as to press the chip to be attached to the surface of the target chip, and complete the bonding of the two chips.

[0029] As a further improvement of the application, in the process of taking the chip to be attached, a pre-alignment process of the chip to be attached and the bonding head is performed, so as to ensure that each alignment through hole is aligned with the first mark point on the chip to be attached.

[0030] and / or

[0031] In the process that the to-be-pasted chip is driven by the first displacement mechanism to above the target chip, a pre-alignment process between the to-be-pasted chip and the target chip is performed.

[0032] The above technical features can be combined with each other as long as they do not conflict with each other.

[0033] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects:

[0034] (1) The wafer bonding device of the present application includes multiple visual components based on infrared detection. By using the combined setting of the two displacement mechanisms and the preferred design of the bonding component, the same visual component can simultaneously realize the simultaneous imaging of the two metal Marks on the to-be-pasted chip and the target chip on the same infrared camera. Through the simultaneous detection of multiple visual components on multiple sets of mark points, the relative positional relationship between the to-be-pasted chip and the target chip is accurately obtained, and the fast and accurate alignment of the target chip before bonding with the to-be-pasted chip is completed. This simplifies the control process during the alignment of the to-be-pasted chip and the target chip, improves the efficiency and accuracy of the alignment and bonding of the to-be-pasted chip and the target chip, and reduces the defect rate of the chip bonding process.

[0035] (2) The wafer bonding method of the present application is realized by using the wafer bonding device with a preferred design. The steps are simple and convenient to control, which can fully simplify the alignment process before bonding of the to-be-pasted chip and the target chip, improve the efficiency of chip alignment and wafer bonding, and reduce the cost of chip bonding processing.

[0036] (3) The wafer bonding device of the present application has a compact structure and is convenient to use. It can realize the imaging detection of the metal Marks on the to-be-pasted chip and the target chip based on double-focus imaging at the same time, represent the Mark information at different heights in the same plane, avoid the frequent alignment and correction process of multiple positioning components, ensure the alignment accuracy of the to-be-pasted chip and the target chip before bonding, improve the quality of chip bonding processing, reduce the defect rate of chip processing, and has good practical value and economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0038] Figure 1 is the overall structure schematic diagram of the wafer bonding device in the embodiments of the present application;

[0039] Figure 2is a schematic diagram of a light path design of a visual assembly in an embodiment of the present application;

[0040] In all the drawings, the same reference signs refer to the same technical features, specifically:

[0041] 1, bonding assembly; 2, first displacement mechanism; 3, second displacement mechanism; 4, first visual assembly; 5, second visual assembly; 6, chip to be pasted; 7, target chip; 8, wafer; 9, bonding table;

[0042] 101, bonding head; 102, plane adjustment module; 103, alignment through hole;

[0043] 201, translation motor; 202, translation guide rail; 203, fixed plate;

[0044] 301, lifting motor; 302, lifting guide rail;

[0045] 401, infrared camera module; 402, first mirror; 403, second mirror; 404, glass lens;

[0046] 601, first mark point; 602, first alignment point; 701, second mark point; 702, second alignment point. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0048] In the description of the present application, it should be understood that, unless otherwise explicitly specified and limited, the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0049] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an ordered sequence. Thus, features referring to "first", "second" etc. can include, explicitly or implicitly, at least one of such features. In the description of the application, the term "a plurality" means at least two, for example two, three, etc., unless expressly and specifically defined otherwise.

[0050] In the present application, unless otherwise expressly and specifically defined, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, they can be fixedly connected, or detachably connected, or integrated; they can be mechanically connected, or electrically connected; they can be directly connected, or indirectly connected through an intermediate medium; they can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise expressly defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] In the present application, unless otherwise expressly and specifically defined, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0052] Embodiment:

[0053] Please refer to Figures 1-2 The wafer bonding device in the preferred embodiment of the present application is suitable for the field of wafer chip bonding, in which the bonding of the to-be-pasted chip 6 and the target chip 7 on the wafer 8 needs to be performed, and the target chip 7 on the wafer 8 is often arranged in an array and needs to be sequentially taken by the bonding device to-be-pasted chip 6, and then the to-be-pasted chip 6 is bonded to the corresponding target chip 7.

[0054] Since the size of the to-be-pasted chip 6 and the target chip 7 is extremely small, a small mechanical error can cause misalignment between the to-be-pasted chip 6 and the target chip 7, and ultimately cause the failure of the bonding process, resulting in defective products. The wafer bonding device in the preferred embodiment of the present application is designed to complete the alignment of the to-be-pasted chip 6 and the target chip 7 on the wafer 8 before bonding, and ultimately achieve accurate bonding of the to-be-pasted chip 6 and the target chip 7.

[0055] In actual arrangement, the end faces of the to-be-pasted chip 6 and the target chip 7 for bonding are each provided with at least two pairs of positioning marks, and the alignment of the two chips is to align the two pairs of positioning marks.

[0056] More specifically, the positioning marks on each chip are preferably arranged at the four corners of the chip, and are further preferably four pairs arranged at the four corner regions. For the to-be-pasted chip 6, each pair of positioning marks arranged on the bonding face thereof includes a first mark point 601 and a first alignment point 602 arranged in pairs and spaced apart by a certain distance; correspondingly, each pair of positioning marks on the target chip 7 includes a second mark point 701 and a second alignment point 702.

[0057] For the chips accurately aligned, the positioning marks at each position on the to-be-pasted chip 6 should be aligned with the positioning marks at the corresponding position on the target chip 7, at which time, the first mark point 601 in the positioning mark is aligned with the second alignment point 702, and the first alignment point 602 is aligned with the second mark point 701, as shown in FIG. 1B. Figure 2

[0058] It can be understood that for the two chips aligned, the first mark point 601 and the second mark point 701 are vertically misaligned.

[0059] More specifically, in the preferred embodiment, the first mark point 601 on the to-be-pasted chip 6 and the second mark point 701 on the target chip 7 are each arranged as a metal Mark, and the bonding device in the preferred embodiment is to align the two metal Marks with the corresponding alignment points.

[0060] Specifically, the bonding device in the preferred embodiment includes a bonding assembly 1, a first displacement mechanism 2 and a second displacement mechanism 3 assembled with each other, a first visual assembly 4 and a second visual assembly 5 arranged corresponding to the bonding assembly 1, and a bonding table 9 for carrying a to-be-bonded wafer 8.

[0061] Among them, the bonding assembly 1 is mainly used for taking the to-be-pasted chip 6, and completing the bonding operation of the to-be-pasted chip 6 on the target chip 7 after taking and aligning.

[0062] In actual arrangement, the bonding assembly 1 includes a bonding head 101 and a plane adjustment module 102, the bonding head 101 is assembled on the plane adjustment module 102 through a connecting shaft, can be driven by the plane adjustment module 102 to perform XYθ adjustment in the plane, so as to change the alignment state of the to-be-pasted chip 6; correspondingly, the bottom surface of the bonding head 101 is a working surface for taking the to-be-pasted chip 6.

[0063] ​Exemplarily, a plurality of negative pressure adsorption holes are formed on the bottom surface of the bonding head 101 in the preferred embodiment, and the adsorption and material taking of the chip 6 to be bonded can be achieved by means of negative pressure adsorption, and the reliable holding of the position state of the chip 6 to be bonded during the bonding process is ensured.

[0064] Further, the first displacement mechanism 2 in the preferred embodiment comprises a translation guide rail 202 and a translation motor 201 assembled on the translation guide rail 202, and the extension direction of the translation guide rail 202 is the horizontal direction, i.e. the X-axis direction shown in FIG. 1. Figure 1 The reciprocating movement control of the object carried on the translation motor 201 in the X-axis direction can be achieved by the reciprocating movement of the translation motor 201 on the translation guide rail 202.

[0065] In actual setting, the second displacement mechanism 3 and the two visual components are simultaneously assembled and connected with the translation motor 201, and can follow the translation motor 201 to perform the reciprocating displacement in the X-axis direction under the guidance of the translation guide rail 202.

[0066] Exemplarily, the second displacement mechanism 3, the first visual component 4 and the second visual component 5 in the preferred embodiment are simultaneously connected on the fixed plate 203 connected with the translation motor 201, and the fixed plate 203 is driven by the translation motor 201 to perform the reciprocating displacement, and then each component provided on the fixed plate 203 is driven by the fixed plate 203 to perform the reciprocating displacement in the X-axis direction.

[0067] More specifically, the second displacement mechanism 3 in the preferred embodiment comprises a lifting guide rail 302 and a lifting motor 301 provided on the lifting guide rail 302. Meanwhile, the bonding head 101 is connected with the lifting motor 301 through the plane adjustment module 102, and the reciprocating movement of the bonding head 101, i.e. the reciprocating displacement in the Z-axis direction shown in FIG. 1, can be achieved by the reciprocating movement of the lifting motor 301 on the lifting guide rail 302. Figure 1

[0068] Correspondingly, the relative position adjustment of the bonding head 101 relative to the lifting motor 301, i.e. the XYθ adjustment in the plane, can also be achieved by the control of the plane adjustment module 102.

[0069] Based on the combined setting of the two displacement mechanisms and the plane adjustment module 102, the coarse adjustment of the plane displacement of the bonding head 101 in the X-axis direction (completed by the first displacement mechanism 2) and the XYθ fine adjustment in the plane (completed by the plane adjustment module 102) can be achieved, and after the adjustment of the plane position is completed, the displacement adjustment in the Z-axis direction is realized by the second displacement mechanism 3, and the bonding operation process after the alignment of the two chips is completed.

[0070] Further specifically, the structures of the two visual components in the preferred embodiment are preferably the same, and the pre-alignment of different parts of the two chips is completed based on the same working principle. ​

[0071] In the preferred embodiment as shown in Figure 1 , the two visual components are preferably arranged in the X-axis direction, as shown in Figure 1 , on the two sides of the second displacement mechanism 3. At this time, the two visual components are respectively used to align the two pairs of positioning marks on the chip 6 to be pasted arranged in the X-axis direction.

[0072] Of course, it can be understood that the two visual components can also be arranged in other forms according to the needs of the arrangement.

[0073] For example, in a specific preferred embodiment, the two pairs of positioning marks on the diagonal position of the chip 6 to be pasted are aligned, at this time, the two visual components are arranged in the X-axis direction. The two visual components are arranged in the X-axis direction.

[0074] For example, in another specific preferred embodiment, the two pairs of positioning marks on the chip 6 to be pasted on one side of the X-axis direction are aligned, at this time, the two pairs of positioning marks are arranged in the Y-axis direction, and the two visual components are arranged on the same side of the bonding component 1 and arranged in the Y-axis direction.

[0075] Of course, in addition to arranging two visual components, three or four visual components can also be arranged for the alignment of the two chips to realize the simultaneous positioning of the two chips in three or four corners and ensure the accuracy of the alignment of the two chips.

[0076] More specifically, the visual component in the preferred embodiment is as shown in Figure 1 , Figure 2 , which includes an infrared camera module 401 including an infrared light source and an infrared camera. Wherein, the infrared light source is used to generate infrared light of a certain waveband, which is reflected to form a detection light path after irradiating on the object to be detected, and finally focused and imaged by the infrared camera on the detection light path, thereby completing the detection of the corresponding object.

[0077] In the preferred embodiment, the optical path of the two detection light paths in the visual component is the same, which is parallelly emitted from the lens of the visual component and simultaneously imaged on the infrared camera.

[0078] Further, the lens of the visual component is arranged directly above the corresponding position of the bonding head 101, and the field of view range corresponding to the lens is vertically (in the Z-axis direction) provided with an alignment through hole 103 on the bonding head 101, so that the infrared light emitted from the lens can be simultaneously emitted to the two mark points on the two chips after passing through the corresponding alignment through hole 103, and the detection and shooting of the metal Mark (i.e. the first mark point 601 and the second mark point 701) on the chip 6 to be pasted and the target chip 7 below the bonding head 101 at the infrared camera are completed.

[0079] In actual settings, in order to facilitate the combination of the visual component and the bonding assembly 1, the infrared camera module 401 in the preferred embodiment is arranged on one side of the bonding assembly 1, and the two infrared detection light paths that can be received by the infrared camera module 401 extend along the Z axis; at the same time, a pair of mirrors, i.e. the first mirror 402 and the second mirror 403, are arranged corresponding to the infrared camera module 401, and the two detection light paths formed by the two metal Marks are reflected by the second mirror 403 and the first mirror 402 and then focused and imaged by the infrared camera in the infrared camera module 401.

[0080] The corresponding arrangement of the two mirrors enables the lens of the visual component and the infrared camera module 401 to be arranged in a staggered manner, so as to adapt to the limited space for arranging the device above the bonding head 101.

[0081] Exemplarily, in a specific preferred embodiment, the two mirrors are arranged at an angle of 45° with the horizontal plane, at this time, the second mirror 403 can reflect the vertical light beam into a horizontal light beam, and the first mirror 402 can convert the horizontal light beam into a vertical light beam again, as shown in FIG. 4B. Figure 1 More specifically, the two mirrors are arranged at intervals in the X axis direction, and the second mirror 403 is located directly above the lens of the visual component in the Z axis direction, at this time, the infrared camera module 401 and the lens are arranged in a staggered manner in the XZ plane.

[0082] At the same time, in order to accurately realize the transmission of the infrared detection light to the to-be-pasted chip 6 and the recognition of the metal Mark, the spectral range of the infrared light emitted by the infrared camera module 401 in the preferred embodiment is between 1100 nm and 1345 nm.

[0083] At the same time, the focusing optical path of the infrared camera module 401 is preferably arranged corresponding to the position of the target chip 7, at this time, the infrared light for detection penetrates the alignment through-hole 103 and the to-be-pasted chip 6 and is shot to the first mark point 601 and the second mark point 701, and two detection light paths are formed by the reflection of the two mark points (the metal Mark does not transmit the infrared light), and the detection of the positions of the two metal Marks is completed by the focusing and imaging of the two detection light paths on the infrared camera.

[0084] However, since there is a spacing H1 between the to-be-pasted chip 6 and the target chip 7, in order to realize the simultaneous focusing and imaging of the two detection light paths on the same infrared camera, it is necessary to shorten the focusing optical path of the detection light path at the first mark point 601 to compensate for the spacing H1 between the two chips.

[0085] To achieve the above process, in a preferred embodiment, a glass lens 404 is provided in the alignment through-hole 103. This glass lens 404 aligns with the chip 6 to be attached in the Z-axis direction after the chip is picked up, ensuring that the detection beam formed by the first marker point 601 can achieve optical path reduction after passing through the glass lens 404. Correspondingly, the detection beam of the second marker point 701 does not pass through the glass lens 404. Simultaneously, to ensure the focusing accuracy of the first marker point 601, the optical path reduction by the glass lens 404 is equal to the vertical distance H1 between the two chips, i.e., the thickness of the glass lens 404. d The following requirements must be met:

[0086] d =H1 / ( n -1)

[0087] In the formula, d H1 represents the thickness of the glass lens 404; H1 represents the optical path direction between the target chip 7 and the chip 6 to be attached (i.e., Figure 2 Spacing along the Z-axis (in the middle); n is the refractive index of glass lens 404.

[0088] More specifically, in the preferred embodiment, the glass lens 404 is smaller than the cross-sectional area of ​​the alignment through-hole 103, ensuring that one of the two detection optical paths always passes through the glass lens 404, while the other passes directly through the alignment through-hole 103 from the outside of the glass lens 404. This ensures two detection optical paths with different actual optical paths, but capable of simultaneous imaging on the same infrared camera, enabling simultaneous imaging of the two marker points on the infrared camera.

[0089] In actual installation, the size of the glass lens 404 is no greater than half the cross-sectional area of ​​the alignment through hole 103.

[0090] For example, in a specific preferred embodiment, the glass lens 404 is positioned to be exactly half the cross-sectional area of ​​the alignment through-hole 103, and is further preferably located on the X-axis side inside the alignment through-hole 103, such as... Figure 2 As shown in the image.

[0091] By simultaneously imaging two metal marks on two chips using a vision component, the relative positional relationship of local areas of the two chips can be accurately obtained. Through processing the image (e.g., determining the center of the metal mark image), it can be determined whether the relative position between the chip to be attached (6) and the target chip (7) requires displacement adjustment in the XY plane. Simultaneously, by combining the detection results from another vision component, it can be determined whether θ adjustment in the XY plane is needed for the chip to be attached (6).

[0092] That is, in combination with the focused imaging of the two visual components, the corresponding detection of the metal mark positions on the two chips can be realized, and through the control of the planar adjustment module 102, the XYθ adjustment of the to-be-pasted chip 6 in the plane before the bonding of the two chips can be accurately completed, so that the alignment of each mark point on the two chips with the corresponding alignment point can be realized, thereby realizing the accurate alignment before the bonding of the two chips. After that, through the control of the second displacement mechanism 3 to perform Z-axis movement, the stroke of the bonding head 101 to press H1 can be controlled, and the accurate bonding of the two chips can be completed.

[0093] It should be noted that when the bonding device performs the bonding operation, the bonding assembly 1 needs to at least go through two processes of taking (taking the to-be-pasted chip 6) and displacement (moving the to-be-pasted chip 6 from the taking position to above the target chip 7), and both processes are completed under precise control. That is to say, when the bonding head 101 sucks the to-be-pasted chip 6, each first mark point 601 on the to-be-pasted chip 6 has a relatively accurate alignment relationship with each alignment through-hole 103 on the bonding head 101, and the first mark point 601 will not be out of alignment with the glass lens 404 in the vertical direction. Moreover, after moving to above the target chip 7, the second mark point 701 will not deviate from the detection field of the infrared detection light.

[0094] Briefly, the bonding device in the preferred embodiment is based on the combined arrangement of the two visual components and the bonding assembly 1, and is designed to realize the accurate alignment of the two to-be-bonded chips under a certain alignment accuracy. Through the corresponding work of the two visual components, the slight error introduced by the mechanical movement of the device can be compensated, so as to ensure the sufficient alignment of the two chips before bonding and improve the quality of chip bonding.

[0095] With the corresponding arrangement of the aforementioned wafer bonding device, the preferred embodiment of the present application further proposes a wafer bonding method realized by using the aforementioned wafer bonding device. The method comprises the following processes:

[0096] (1) The bonding assembly 1 is driven by the first displacement mechanism 2 to a taking station and the taking of the to-be-pasted chip 6 is completed.

[0097] At this time, the to-be-pasted chip 6 that has completed the taking is adsorbed on the bottom surface of the bonding head 101, and each first mark point 601 on the to-be-pasted chip 6 is aligned with the glass lens 404 in the corresponding alignment through-hole 103, and the first alignment point 602 corresponds to the through-hole region outside the glass lens 404.

[0098] The alignment process of the to-be-pasted chip 6 and the bonding head 101 can be realized by a pre-alignment process, which can be realized by setting an additional alignment mechanism or by detection of each visual component. For example, when the to-be-pasted chip 6 is taken, multiple visual components are turned on at the same time to ensure that each alignment through-hole 103 has a first mark point 601 focused and imaged.

[0099] It can be understood that in the above pre-alignment process, each vision component is synchronously controlled to displace with the bonding assembly 1.

[0100] In addition to the above pre-alignment method, the pre-alignment between the to-be-pasted chip 6 and the bonding head 101 can also be realized through precise mechanical control, and the accuracy of the to-be-pasted chip 6 when taking the material is ensured by pre-setting the accurate stroke displacement parameters.

[0101] (2) Control the first displacement mechanism 2 to drive the bonding assembly 1 and the two vision components to synchronously displace in the X-axis direction, and drive the to-be-pasted chip 6 to above the corresponding target chip 7, which is arranged on the corresponding wafer 8, and the wafer 8 is carried on the bonding table 9;

[0102] As above, when the first displacement mechanism 2 is controlled, the pre-alignment process between the target chip 7 and the to-be-pasted chip 6 is also performed, which can be completed through precise mechanical control or through pre-work of at least one vision component, and details are not repeated here.

[0103] (3) Control each vision component to work respectively, and generate infrared light by each vision component to focus and image the first mark point 601 on the to-be-pasted chip 6 and the second mark point 701 on the target chip 7, so as to obtain imaging information of multiple groups of mark points (for example, two groups shown in the figure, and each group of mark points includes a first mark point 601 and a second mark point 701); Figure 1

[0104] (4) Process the imaging information of multiple groups of mark points to obtain the relative position relationship between the two chips, and then obtain the XYθ adjustment information of the to-be-pasted chip 6; thereafter, control the plane adjustment module 102 to work to adjust the position of the to-be-pasted chip 6 to be accurately aligned with the target chip 7 in the Z-axis direction;

[0105] (5) Control the second displacement mechanism 3 to work to press the to-be-pasted chip 6 along the Z-axis to the surface of the target chip 7, and complete the bonding of the two chips.

[0106] The processes in cycles (1)-(5) are repeated to complete the bonding process between multiple to-be-pasted chips 6 and corresponding target chips 7.

[0107] The wafer bonding device in the application has the advantages of compact structure, convenient use, simultaneous imaging detection of metal Marks on the to-be-pasted chip and the target chip based on double-focus imaging, representation of metal Mark information at different heights in the same plane, avoidance of frequent alignment and correction processes of multiple positioning components, guarantee of the alignment accuracy of the to-be-pasted chip and the target chip before bonding, improvement of the quality of chip bonding processing, reduction of the defective rate of chip processing, good practical value and economic benefits, and the like. ​

[0108] It is to be understood that the above description is intended to be illustrative and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the application should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A wafer bonding apparatus, characterized by comprising: The application relates to a bonding assembly, which comprises a bonding head for picking up a chip to be bonded, the bonding head being connected to a plane adjustment module for driving the bonding head to perform XY theta adjustment in a plane; a bonding table for carrying a target chip to be bonded with the chip to be bonded; a first displacement mechanism and a second displacement mechanism; the plane adjustment module is assembled on the second displacement mechanism, the bonding head can be driven by the second displacement mechanism to approach or move away from the bonding table; the second displacement mechanism is assembled on the first displacement mechanism and can be driven by the first displacement mechanism to perform horizontal displacement; at least two visual assemblies, the visual assembly comprising an infrared camera module having an infrared light source for emitting infrared light and an infrared camera for focusing and imaging the infrared light; the light path of the infrared light emitted from the visual assembly lens is perpendicular to the mutually parallel chip to be measured and the target chip; and the lens corresponding to each visual assembly is respectively provided with an alignment through hole on the bonding head; the infrared light emitted from each visual assembly lens is respectively emitted to a first mark point on the chip to be bonded and a second mark point on the target chip after penetrating through the alignment through hole and the chip to be bonded; both mark points are metal Marks, the infrared light forms two detection light paths after irradiating the two metal Marks; and a glass lens is arranged in the alignment through hole, the detection light path of the first mark point is simultaneously imaged with another detection light path not penetrating through the glass lens on the infrared camera after penetrating through the glass lens; the glass lens satisfies that the spectral range of the infrared light is between 1100 nm and 1345 nm. Each displacement mechanism comprises a guide rail and a motor assembled on the guide rail; the guide rail of the second displacement mechanism is connected with the motor of the first displacement mechanism and can follow the motor to perform horizontal displacement; and the plane adjustment module is connected with the motor of the second displacement mechanism and can follow the motor to perform lifting displacement. A fixing plate is connected and arranged on the motor of the first displacement mechanism, and the at least two visual assemblies and the guide rail of the second displacement mechanism are simultaneously mounted on the fixing plate. The visual assembly is two visual assemblies separately arranged on two sides of the bonding assembly and used for detecting mark points at two ends of the chip to be bonded. The setting size of the glass lens is not greater than half of the cross-sectional area of the alignment through hole. The bottom surface of the bonding head is a working surface, a plurality of negative pressure adsorption holes are arranged on the working surface, and the chip to be bonded is picked up by using a negative pressure adsorption mode. d =H1 / （ n -1） In the formula, d is the thickness of the glass lens; H1 is the distance between the target chip and the chip to be pasted in the optical path direction; n is the refractive index of the glass lens.

2. The wafer bonding apparatus according to claim 1, wherein The infrared camera module in the visual assembly is arranged in a dislocation mode with the lens of the visual assembly, and a mirror group is arranged between the infrared camera module and the lens; the mirror group comprises at least one mirror.

3. The wafer bonding apparatus of claim 2, wherein The mirror group comprises a first mirror and a second mirror arranged in a horizontal direction.

4. The wafer bonding apparatus according to claim 3, wherein The two mirrors are arranged at an angle of 45 degrees with a horizontal plane, and are used for reflecting a detection light path from the infrared camera module from a vertical direction to a horizontal direction and finally to a vertical detection light path again.

5. The wafer bonding apparatus according to any one of claims 1 to 4, characterized by, The application further discloses a process, which comprises the following steps: (1) controlling the bonding head to pick up the chip to be bonded; (2) controlling the first displacement mechanism to move, so as to drive the bonding head to above the corresponding target chip; 6. The wafer bonding apparatus according to any one of claims 1 to 4, wherein ​ 7. The wafer bonding apparatus according to any one of claims 1 to 4, wherein ​ 8. The wafer bonding apparatus according to claim 7, wherein, ​ ​ 9. A wafer bonding method using the wafer bonding apparatus according to any one of claims 1 to 8, characterized by, ​ ​ ​ (3) Controlling each vision component to work respectively, and each vision component respectively carries out infrared focusing imaging on the pair of first mark points and second mark points to obtain imaging information of multiple groups of mark points; (4) Processing the imaging information of multiple groups of mark points to obtain the relative position relationship between the two chips and obtain XYθ adjustment information of the chip to be pasted; thereafter, controlling the plane adjustment module to work to accurately align the chip to be pasted with the target chip; (5) Controlling the second displacement mechanism to work to press the chip to be pasted to the surface of the target chip to complete the bonding of the two chips.

10. The wafer bonding method according to claim 9, wherein, In the process of taking the chip to be pasted, the pre-alignment process of the chip to be pasted and the bonding head is carried out to ensure that each alignment through hole is aligned with the first mark point on the chip to be pasted; And / or In the process of driving the chip to be pasted by the first displacement mechanism to the top of the target chip, the pre-alignment process between the chip to be pasted and the target chip is carried out.

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