A bonded-wave real-time detection device and method

Abstract

The application relates to a bonded wave real-time detection device and method, and relates to a detection device and method. The application is used to solve the problems of bonded wave detection rate lag, difficulty in real-time acquisition of a bonded wave dynamic propagation process and single detection dimension in the prior art. The detection device comprises a lower table plate, an upper table plate, a bonding head, a supporting structure, a micro probe detection system and an infrared camera detection system. The micro probe detection system utilizes an optical interferometer to build a multi-point synchronous detection system, realizes real-time acquisition of global multi-point distance changes of a wafer in a wafer bonding pressing process, and the infrared camera detection system can obtain the propagation process of the bonded wave through the difference of reflectivity of a bonding interface. The application can realize real-time monitoring of the bonded wave, dynamically adjusts bonding parameters based on displacement field data, can improve bonding quality control capability, reduces defects, has the advantages of strong real-time performance and high detection precision. The application belongs to the chip packaging technical field.

Description

Technical Field

[0001] This invention relates to a detection device and method, belonging to the field of chip packaging technology. Background Technology

[0002] In semiconductor packaging, wafer bonding, and precision bonding processes, the bonding wave is a dynamic contact front formed by the gradual expansion of the interface to be bonded from the initial contact position outwards during the contact process. The propagation state of the bonding wave directly affects the final bonding quality. When the bonding wave propagates unevenly, has an abnormal propagation speed, or is locally obstructed, defects such as voids, bubbles, unbonded areas, and uneven interface stress can easily form at the bonding interface, thereby affecting the device yield, reliability, and service performance.

[0003] In existing technologies, bonding quality inspection is mostly performed after bonding is complete, typically using infrared detection, ultrasonic testing, or other offline methods to evaluate the overall state after bonding. While these methods can reflect the final bonding result to some extent, they usually only provide static information after bonding is complete, failing to reflect the real-time propagation of the bonding wave during the bonding process, nor can they promptly capture the dynamic process of bonding anomalies. Therefore, existing inspection methods exhibit significant lag, making it difficult to identify defects in their early stages and adjust process parameters in a timely manner.

[0004] Furthermore, in actual bonding processes, the propagation of the bonding wave not only manifests as the gradual expansion of the contact area within a plane, but also involves minute displacements and deformations of the components to be bonded within localized regions. Relying solely on a single imaging method is insufficient to accurately reflect the true state of dynamic interface contact, while relying solely on a single sensor signal lacks a direct representation of the bonding wave propagation path and morphology. Therefore, it is difficult to simultaneously achieve both intuitiveness and accuracy in detection. Based on this, there is an urgent need for a real-time detection device and method capable of simultaneously acquiring bonding wave image information and displacement change information during the bonding process, in order to more accurately characterize the bonding wave propagation behavior and provide an effective basis for bonding process control. Summary of the Invention

[0005] To address the problems of lagging bond wave detection, difficulty in obtaining the dynamic propagation process of bond waves, and limited detection dimensions in existing technologies, this invention proposes a real-time bond wave detection device and method.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: The present invention provides a real-time bonding wave detection device including a support structure, a lower table plate on the support structure, an upper table plate installed on the lower table plate, a micro probe detection system installed on the upper table plate, a bonding head also installed on the support structure, and the bonding head is located above the upper table plate. An infrared camera detection system is installed at the lower part of the support structure.

[0007] Furthermore, the support structure includes a cast iron platform, the upper surface of which is provided with a marble base. The marble base is fixed to the upper surface of the cast iron platform by angle iron. The upper surface of the marble base is provided with a gantry beam. The two ends of the gantry beam are fixedly connected to the upper surface of the marble base by gantry columns. The marble base is also provided with a support frame for installing the lower table. The key head is installed on the gantry beam.

[0008] Furthermore, the bonding head includes a support arm, which is mounted on the gantry beam. A rotary motor is mounted on the support arm, and a lead screw is mounted on the motor shaft of the rotary motor. A slider is fitted on the lead screw, and the slider is slidably connected to the bonding head guide rail mounted on the support arm. A thin cylinder is mounted on the slider, and a force sensor is mounted on the front end of the bonding head at the lower end of the thin cylinder.

[0009] Furthermore, the upper table includes a motion main board, which is mounted on a guide rail assembly. The guide rail assembly is mounted on a support structure. One side of the motion main board is rotatably connected to one side of the flipping component via a rotary assembly. A micro probe detection system is mounted on the lower surface of the flipping component, and a lifting pusher is provided on the upper surface of the flipping component.

[0010] Furthermore, the guide rail assembly includes two SP-grade mechanical guide rails arranged side by side and parallel on the support structure. A slider is slidably connected to the SP-grade mechanical guide rail, and the motion main board is fixed on the slider. A limit block is provided at the front end of the SP-grade mechanical guide rail, and an anti-collision block is provided at the rear end of the SP-grade mechanical guide rail.

[0011] Furthermore, the lower table includes a ZTT piezoelectric displacement stage, on the upper surface of which a super-flat block is installed. The surface of the super-flat block is provided with multiple adapters and fixing parts along the circumferential direction, and the side of the super-flat block is provided with multiple negative pressure pipelines.

[0012] Furthermore, the ultraflat block is made of silicon carbide material.

[0013] Furthermore, the microprobe detection system consists of 50 microprobe fiber optic interferometers, which are deployed in a distributed manner.

[0014] The steps of the real-time detection method for bonding waves described in this invention include: Step 1: Use the rotary handshake to rotate the flipping component around the rotary assembly, install the lower wafer on the lower table, and use the motion motherboard to drive the upper table to slide on the SP-level mechanical guide rail; Step 2: Mechanical locking and adjustment of the distance and parallelism between the upper and lower tables are achieved by using a super-flat block and a ZTT piezoelectric displacement stage; Step 3: Apply bonding force through the bonding head to trigger the bonding process; Step 4: The microprobe detection system activates the 50-channel synchronous acquisition mode. The microprobe fiber interferometer acquires 50-point distance data in real time from the initial position of the upper wafer to the bonding of the lower wafer. The acquisition frequency is 1kHz. The operator can view the displacement data of each point and the global flatness cloud map in real time through the industrial control computer. At the same time, the large-target InGaAs infrared camera of the infrared camera detection system realizes bonding wave imaging covering the entire radial direction of the wafer. Each frame contains the position of the bonding wave front, global contour and distortion on the entire wafer.

[0015] The beneficial effects of this invention are: 1. This invention innovatively employs an array-type reflective fiber optic displacement sensor as the core sensing unit to construct a closed-loop detection system. Fifty miniature fiber optic probes are embedded in a ring array on a table, with the probe spacing optimized according to the wafer size. Based on the principle of light intensity modulation, the sensor measures the normal micro-displacement of the bonding interface caused by atomic diffusion during the bonding process in real time by emitting a laser beam. Triggered by the bonding initiation signal, each probe synchronously records the displacement-time waveform at the arrival of the interface wave, with the sampling window covering the entire bonding wave diffusion stage. A high-speed data acquisition card synchronously records multi-channel displacement signals, which are then transmitted to the host computer in real time after photoelectric conversion, amplification, and filtering. The first peak moment of each channel waveform is extracted, and based on the time-of-arrival algorithm, the starting position and propagation velocity field of the bonding wave on the wafer plane are inverted. The amplitude and wave velocity characteristic values ​​corresponding to the discrete probe coordinates are extended to the entire wafer plane using a Kriging interpolation algorithm, generating a continuous distribution field with sub-millimeter resolution. The host computer runs real-time monitoring software to complete feature extraction and cloud map reconstruction. Using heat map coloring technology, the amplitude data is mapped to a color gradient (blue to red indicates energy increase), and a dynamic evolution cloud map of the interface wave diffusion is generated frame by frame to realize real-time display of the wavefront advancement process.

[0016] 2. This invention mounts an InGaAs infrared camera on the support frame of the base to perform real-time, high-precision detection of the bonding wave propagation process. The innovative combination of a micro-probe detection system and an infrared camera detection system cleverly solves the lag problem of traditional detection methods, more accurately characterizes the bonding wave propagation behavior, and provides an effective basis for bonding process control. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the bonding wave real-time detection device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the upper table structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the lower table structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the bonding head structure according to an embodiment of the present invention; Figures 1 to 4 In the middle, 1-lower tabletop, 2-upper tabletop, 3-bonding head, 4-support structure, 5-micro probe detection system, 6-infrared camera detection system, 101-ultra-flat block, 102-adapter fixing component, 103-negative pressure pipeline, 104-ZTT piezoelectric displacement stage, 201-motion mainboard, 202-flipping component, 203-rotation assembly, 204-guide rail assembly, 205-lifting pusher, 25-SP grade mechanical guide 26-Anti-collision block, 27-Limit block, 28-Slider, 31-Support arm, 302-Thin cylinder, 303-Force sensor, 304-Front end of bonding head, 305-Lead screw, 306-Rotary motor, 307-Bond head guide rail, 401-Marble base, 402-Cast iron platform, 403-Gantry beam, 404-Gantry column, 405-Support frame, 501-Micro probe fiber optic interferometer. Detailed Implementation

[0018] Specific implementation method one: as follows Figures 1 to 4 As shown, the real-time bonding wave detection device described in this embodiment includes a lower plate 1, an upper plate 2, a bonding head 3, a support structure 4, a microprobe detection system 5, and an infrared camera detection system 6. The lower plate 1 is used to adjust the spacing between the upper plate 2 and the lower plate 2, as well as the parallelism adjustment during the bonding process. The upper plate 2 is used to realize the loading and unloading of wafers and mechanical alignment. The bonding head 3 completes the loading, monitoring, and triggering of bonding force. The support structure 4 provides support for the lower plate 1, the upper plate 2, the bonding head 3, the microprobe detection system 5, and the infrared camera detection system 6.

[0019] Among them, the supporting structure 4 includes a marble base 401, a cast iron platform 402, a gantry beam 403, a gantry column 404, and a support frame 405; The lower table 1 includes a super-flat block 101, a connecting fastener 102, a negative pressure pipeline 103, and a ZTT piezoelectric displacement stage 104; The upper table 2 includes a motion main board 201, a flipping component 202, a rotation component 203, a guide rail component 204, and a lifting pusher 205; The guide rail assembly 204 includes an SP-grade mechanical guide rail 25, an anti-collision block 26, a limit block 27, and a slider 28; the main board 201 drives the entire upper table plate 2 to slide on the SP-grade mechanical guide rail 25, realizing the misalignment avoidance when the upper table plate 2 and the lower table plate 1 are placed on top and bottom; the flipping component 202 and the rotating assembly 203 are connected.

[0020] The bonding head 3 includes a support arm 31, a thin cylinder 302, a force sensor 303, and a bonding head front end 304; the bonding head 3 is fixed to the crossbeam of the marble base 4 by a lead screw.

[0021] The microprobe inspection system 5 includes 50 microprobe fiber interferometers 501, which are distributed in a manner that adheres to the principles of full coverage, balanced density, and increased density at key points, while also considering the wafer center, edges, and transition areas to avoid blind spots. The probe placement must avoid the wafer bonding head and the core area of ​​the bonding interface to prevent interference with normal bonding operations. All probes are perpendicular to the upper wafer surface to ensure accurate distance detection. The specific distribution scheme is as follows: The central core area is equipped with five micro-probe fiber interferometers 501. There are no probes at the geometric center of the wafer, but they are evenly distributed in a ring around the perimeter to detect the reference value of the pressure center. Inner ring transition area: 15 micro-probe fiber interferometers 501 are arranged in a ring area with a radius of 30mm, with the center as the origin. The 15 micro-probe fiber interferometers 501 are evenly distributed at the same angle to detect the downward pressure state in the middle of the wafer. Outer ring edge area: 30 micro-probe fiber optic interferometers 501 are arranged in a 120mm radius ring area. The 30 micro-probe fiber optic interferometers 501 are densely arranged at the same angle to control the edge pressing accuracy.

[0022] The micro-probe fiber interferometer 501 is embedded in a ring array on the upper table plate 2, and the probe spacing is arranged according to the wafer size.

[0023] The main component of the infrared camera inspection system 6 is a large-area InGaAs infrared camera. By employing a low-magnification, large-field-of-view infrared telecentric lens / macro objective, in conjunction with the large-area InGaAs infrared camera, the infrared camera inspection system 6 achieves single-shot imaging covering the entire radial direction of the wafer without scanning or moving parts. Each frame contains the position of the bonding wavefront, the global profile, and distortions across the entire wafer.

[0024] Among them, the ultra-flat block 101 is made of silicon carbide material, and the pin corner is designed to achieve mechanical locking.

[0025] Among them, the ZTT piezoelectric displacement stage 104 is a three-degree-of-freedom piezoelectric displacement stage, which can realize the stroke adjustment in the z-axis direction and the deflection adjustment in the Rx and Ry directions.

[0026] Among them, the motion motherboard 101 has four positioning surfaces to ensure the spacing between the upper and lower wafers and the parallelism between the upper and lower wafers.

[0027] After the flipping component 202 and the rotating component 203 are connected, they can be flipped 180° around the rotating axis for use on the upper table 2.

[0028] The guide rail assembly 204 achieves alignment of the upper and lower wafers through mechanical positioning.

[0029] The support arm 31 includes a lead screw 305, a rotary motor 306, and a bonding head guide rail 307; the bonding head 3 is fixed to the marble beam of the marble base 401 by the lead screw 305, and the size adjustment of the bonding head 3 to the upper wafer is performed by the rotary motor 306.

[0030] Force sensor 303 is a piezoelectric sensor.

[0031] The front end of the bonding head is made of 304 alloy steel with a rounded shape.

[0032] Specific Implementation Method Two: The steps of the real-time detection method for bonded waves described in this implementation method include: Step 1: The upper table and the flipping component 202 are rotated 180° around the rotating assembly 203 by the rotary handshake to realize the loading of the upper table 2 and the lower wafer is installed on the lower table 1. In order to make the upper table 2 and the lower table 1 misaligned and avoid each other when loading and unloading the wafer, the motion motherboard 201 is used to drive the upper table 2 to slide on the mechanical guide rail 25. Step 2: After the film is loaded, mechanical locking and adjustment of the spacing and parallelism of the upper and lower tables are achieved by using the ultra-flat block 101 and ZTT piezoelectric displacement stage 104; Step 3: Apply bonding force through bonding head 3 to trigger bonding; Step 4: The microprobe detection system 5 activates the 50-channel synchronous acquisition mode. The microprobe fiber interferometer 501 acquires 50-point distance data in real time from the initial position of the upper wafer to the bonding of the lower wafer. The acquisition frequency is 1kHz. The operator can view the displacement data of each point and the global flatness cloud map in real time through the industrial control computer. At the same time, the large target surface InGaAs infrared camera 601 of the infrared camera detection system 6 realizes bonding wave imaging covering the entire radial direction of the wafer. Each frame contains the bonding wave front position, global contour and distortion on the entire wafer.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A real-time bonding wave detection device, characterized in that, The system includes a support structure (4), a lower table (1) on the support structure (4), an upper table (2) on the lower table (1), a micro probe detection system (5) on the upper table (2), a bonding head (3) on the support structure (4), and the bonding head (3) is located above the upper table (2). An infrared camera detection system (6) is installed on the lower part of the support structure (4).

2. The real-time bonding wave detection device according to claim 1, characterized in that, The support structure (4) includes a cast iron platform (402), a marble base (401) is provided on the upper surface of the cast iron platform (402), the marble base (401) is fixed on the upper surface of the cast iron platform (402), a gantry beam (403) is provided on the upper surface of the marble base (401), the two ends of the gantry beam (403) are fixedly connected to the upper surface of the marble base (401) through gantry columns (404), and a support frame (405) is also provided on the marble base (401). The support frame (405) is used to install the lower table (1), and the key head (3) is installed on the gantry beam (403).

3. The real-time bonding wave detection device according to claim 2, characterized in that, The bonding head (3) includes a support arm (31), which is mounted on the gantry beam (403). A rotary motor (306) is mounted on the support arm (31), and a lead screw (305) is mounted on the motor shaft of the rotary motor (306). A slider is mounted on the lead screw (305), and the slider is slidably connected to the bonding head guide rail (307) mounted on the support arm (31). A thin cylinder (302) is mounted on the slider, and a force sensor (303) is mounted on the bonding head front end (304) at the lower end of the thin cylinder (302).

4. The real-time bonding wave detection device according to claim 1, characterized in that, The upper table (2) includes a motion main board (201), which is mounted on a guide rail assembly (204). The guide rail assembly (204) is mounted on a support structure (4). One side of the motion main board (201) is rotatably connected to one side of the flipping part (202) through a rotary assembly (203). A micro probe detection system (5) is mounted on the lower surface of the flipping part (202), and a lifting pusher (205) is provided on the upper surface of the flipping part (202).

5. The real-time bonding wave detection device according to claim 4, characterized in that, The guide rail assembly (204) includes two SP-grade mechanical guide rails (25) arranged side by side on the support structure (4). A slider (28) is slidably connected to the SP-grade mechanical guide rail (25). The motion main board (201) is fixed on the slider (28). The front end of the SP-grade mechanical guide rail (25) is pressed against the limiting block (28). The rear end of the SP-grade mechanical guide rail (25) is provided with an anti-collision block (26).

6. The real-time bonding wave detection device according to claim 1, characterized in that, The lower table (1) includes a ZTT piezoelectric displacement stage (104). A super-flat block (101) is installed on the upper surface of the ZTT piezoelectric displacement stage (104). Multiple adapters (102) are provided on the surface of the super-flat block (101) along the circumferential direction. Multiple negative pressure pipelines (103) are provided on the side of the super-flat block (101).

7. The real-time bonding wave detection device according to claim 6, characterized in that, The superflat block (101) is made of silicon carbide material.

8. The real-time bonding wave detection device according to claim 1, characterized in that, The microprobe detection system (5) consists of 50 microprobe fiber interferometers (501), which are distributed in a distributed manner.

9. A method for real-time detection of bonding waves based on the detection device according to any one of claims 1 to 8, characterized in that, The specific steps include: Step 1: Rotate the flipping component (202) around the rotating assembly (203) by rotating the handshake, and install the lower wafer on the lower table plate (1). Use the motion motherboard (201) to drive the upper table plate (2) to slide on the SP-level mechanical guide rail (25); Step 2: Mechanical locking and adjustment of the distance and parallelism between the upper table plate (2) and the lower table plate (1) are achieved by using the super-flat block (1) and the ZTT piezoelectric displacement stage (104); Step 3: Apply bonding force through the bonding head (3) to trigger the bonding process; Step 4: The micro probe detection system (5) starts the 50-channel synchronous acquisition mode. The micro probe fiber interferometer (501) collects the distance data of 50 points of the upper wafer from the initial position to the bonding of the lower wafer in real time. The acquisition frequency is 1kHz. The operator can view the displacement data of each point and the flatness cloud map of the whole area through the industrial control computer in real time. At the same time, the large target surface InGaAs infrared camera (601) of the infrared camera detection system (6) realizes the bonding wave imaging covering the entire radial direction of the wafer. Each frame contains the bonding wave front position, global contour and distortion on the entire wafer.

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