Ultrasonic detection of voids and cracks in substrates
By combining ultrasonic transducers and detectors with a processor, the problem of optical inspection being unable to detect defects in semiconductor substrates has been solved, enabling efficient inspection and repair of opaque or multilayer material substrates and improving the production yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ORBOTECH LTD
- Filing Date
- 2024-09-23
- Publication Date
- 2026-04-17
AI Technical Summary
Existing optical inspection methods are ineffective at detecting defects in semiconductor substrates, especially for opaque substrates or substrates composed of multiple layers of materials, leading to a decrease in production yield.
A method combining an ultrasonic transducer and detector with a processor is employed. By controlling the ultrasonic transducer to generate acoustic signals and receiving reflected signals, defects in the substrate are detected by comparing phase and intensity, and repair is performed by repairing the acoustic signals.
It improves the detection accuracy and repair efficiency of various types of substrate defects, especially for opaque or multilayer substrates, thereby increasing the production yield and detection resolution.
Smart Images
Figure CN121889671A_ABST
Abstract
Description
[0001] Cross-reference of related applications
[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 542,343, filed and assigned on October 4, 2023, and U.S. Provisional Patent Application No. 63 / 612,346, filed and assigned on December 19, 2023, the entire disclosure of which is hereby incorporated by way of introduction. Technical Field
[0003] This disclosure relates to inspection systems, and more specifically to inspection systems for detecting defects in semiconductor substrates. Background Technology
[0004] The evolution of the electronics manufacturing industry places higher demands on yield management, and specifically on metrology and inspection systems. Critical dimensions continue to shrink, but the industry needs to shorten timelines to achieve high yield rates and high-value production. Minimizing the total time from detecting a yield problem to resolving it maximizes the return on investment for electronics manufacturers.
[0005] Inspection processes are used at various stages of electronics manufacturing to detect defects in wafers, electronic devices, or circuits, thereby promoting higher yields and, consequently, higher profits. Inspection has always been a crucial part of manufacturing electronic devices such as integrated circuits (ICs), flat panel displays (e.g., organic light-emitting diode-on-silicon (OLEDoS) display panels), and printed circuit boards (PCBs) (including the assembled PCBs). However, as feature sizes shrink, inspection becomes even more critical for the successful manufacture of acceptable electronic devices, as even small defects can render devices and assemblies unacceptable. For example, with decreasing feature sizes, the detection of defects of reduced size becomes necessary because even relatively small defects can cause unwanted aberrations in the device.
[0006] Many inspection processes rely on optical inspection systems to identify defects. However, when the material is diffuse, opaque, or consists of multiple layers, optical inspection of defects can be difficult or impossible.
[0007] Therefore, a method is needed to detect defects in various types of substrates to improve production yield. Summary of the Invention
[0008] Embodiments of this disclosure provide a method. The method may include: attaching an ultrasonic transducer to a substrate; attaching an ultrasonic detector to the substrate; controlling the ultrasonic transducer with a processor to generate an acoustic signal applied to the substrate; receiving, with the processor, a reflected acoustic signal detected by the ultrasonic detector; and determining, with the processor, defects in the substrate based on a comparison of the phase and intensity of the reflected acoustic signal with the acoustic signal applied to the substrate.
[0009] In some embodiments, the substrate may include silicon, glass, ceramic or organic materials, and the defect may be a void or crack in the substrate.
[0010] In some embodiments, the substrate may include a printed circuit board. The ultrasonic transducer may be attached to a metal line on the printed circuit board, and the ultrasonic detector may be attached to the metal line. The defect may be a crack in the metal line or a gap between repaired segments of the metal line.
[0011] In some embodiments, the ultrasonic detector may be attached to the substrate remotely from the ultrasonic transducer.
[0012] In some embodiments, the ultrasonic detector may be attached to the substrate at the same location as the ultrasonic transducer.
[0013] In some embodiments, the method may further include using the processor to control the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair the defect.
[0014] In some embodiments, the method may further include depositing welding material into the substrate to repair the defect.
[0015] Another embodiment of this disclosure provides a method. The method may include: attaching a multi-segment ultrasonic transducer to a chip, wherein the chip is disposed on a substrate, and an underfill material is disposed between the chip and the substrate; attaching an ultrasonic detector to the chip; controlling the multi-segment ultrasonic transducer to generate acoustic signals applied to the chip from each segment, wherein the acoustic signals from each segment of the multi-segment ultrasonic transducer have a phase delay; receiving reflected acoustic signals detected by the ultrasonic detector using the processor; and determining defects in the underfill material using the processor based on the phase and intensity of the reflected acoustic signals.
[0016] In some embodiments, the phase delay of the acoustic signal from each segment of the multi-segment ultrasonic transducer can focus the sound wave at a different depth relative to the chip, such that the sound wave can be reflected by the underfill material and detected by the ultrasonic detector.
[0017] In some embodiments, the method may further include using the processor to control the multi-segment ultrasonic transducer to generate an acoustic signal from at least one segment applied to the defect in the underfill material to repair the defect. The acoustic signal applied to the defect may be configured to melt or sinter the underfill material to repair the defect.
[0018] Another embodiment of this disclosure provides a method. The method may include: positioning an ultrasonic transducer proximal to a first side of a substrate; controlling the ultrasonic transducer with a processor to generate an acoustic signal applied to the substrate; scanning a laser beam across a second side of the substrate using a laser source, wherein the first side is opposite to the second side; detecting a reflected laser beam with a detector, wherein the reflected laser beam is a reflection of the laser beam from the second side of the substrate; and determining defects in the substrate using the processor based on phase and amplitude changes in the reflected laser beam received from the detector.
[0019] In some embodiments, the method may further include using the processor to control the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair the defect.
[0020] In some embodiments, before the processor controls the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair the defect, the method may further include scanning the substrate relative to the ultrasonic transducer to position the ultrasonic transducer close to the defect in the substrate.
[0021] Another embodiment of this disclosure provides a method. The method may include: positioning an ultrasonic transducer and an ultrasonic detector close to a substrate; controlling the ultrasonic transducer to emit sound waves toward the substrate, wherein the sound waves are reflected by the substrate and received by the ultrasonic detector; scanning the substrate relative to the ultrasonic transducer and the ultrasonic detector; and, while scanning the substrate, using the processor to determine defects in the substrate based on changes in the phase or intensity of the reflected sound waves detected by the ultrasonic detector.
[0022] In some embodiments, the substrate may be a solid-state battery, and the defect may be a crack or dendritic protrusion in the solid-state battery.
[0023] In some embodiments, the method may further include using the processor to control the ultrasonic transducer to emit acoustic waves applied to the defect in the substrate to repair the defect.
[0024] In some embodiments, before the processor controls the ultrasonic transducer to emit acoustic waves applied to the defect in the substrate to repair the defect, the method may further include scanning the substrate relative to the ultrasonic transducer to position the ultrasonic transducer close to the defect in the substrate. Attached Figure Description
[0025] For a more complete understanding of the nature and purpose of this disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
[0026] Figure 1A This is a flowchart of a detection method according to an embodiment of the present disclosure;
[0027] Figure 1B use Figure 1A A systematic diagram of the method;
[0028] Figure 1C It is to utilize Figure 1A Another systematic diagram of the method;
[0029] Figure 2A This is a flowchart of a detection method according to another embodiment of the present disclosure;
[0030] Figure 2B It is to utilize Figure 2A A systematic diagram of the method;
[0031] Figure 3A This is a flowchart of a detection method according to another embodiment of the present disclosure;
[0032] Figure 3B It is to utilize Figure 3A A systematic diagram of the method;
[0033] Figure 4A This is a flowchart of a detection method according to another embodiment of the present disclosure;
[0034] Figure 4B It is to utilize Figure 4A A systematic diagram of the method;
[0035] Figure 5A and 5B The diagram illustrates the repair process of an embodiment of this disclosure;
[0036] Figure 6A and 6B The diagram illustrates the repair process of another embodiment of this disclosure; and
[0037] Figures 7A to 7C The diagram illustrates the repair process of another embodiment of this disclosure. Detailed Implementation
[0038] Although the claimed subject matter will be described with reference to some embodiments, other embodiments that do not provide all the benefits and features set forth herein are also within the scope of this disclosure. Various structural, logical, procedural, and electronic changes may be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure is defined only by reference to the appended claims.
[0039] Embodiments of this disclosure relate to using ultrasound to detect defects in a substrate 101. Such a substrate 101 may include a semiconductor wafer, a substrate (made of silicon, glass, ceramic, or organic materials), a printed circuit board (including metal lines made of copper or other conductive materials), a solid-state battery, or other materials / devices. The system 100 of various embodiments of this disclosure may include an ultrasonic transducer 110, an ultrasonic detector 120, and a processor 130. Generally, the processor 130 may be configured to control the ultrasonic transducer 110 to generate an acoustic signal applied to the substrate 101, and the ultrasonic detector 120 may detect reflected acoustic signals from the substrate 101. The processor 130 may be configured to receive reflected acoustic signals from the substrate 101 and determine the presence of a defect 102 in the substrate 101 based on a comparison of the phase and intensity of the reflected acoustic signals with the acoustic signals applied to the substrate 101.
[0040] Processor 130 may include a microprocessor, microcontroller, or other device. Processor 130 may be coupled to components of system 100 in any suitable manner (e.g., via one or more transmission media, which may include wired and / or wireless transmission media) to enable processor 130 to receive output. Processor 130 may be configured to use the output to perform several functions. Inspection tools may receive instructions or other information from processor 130. Optionally, processor 130 may electronically communicate with another inspection tool, metrology tool, repair tool, or re-inspection tool (not shown) to receive additional information or send instructions.
[0041] Processor 130 may be part of a variety of systems, including personal computer systems, graphics computers, mainframe computer systems, workstations, network appliances, Internet appliances, or other devices. A subsystem or system may also include any suitable processor known in the art, such as a parallel processor. Additionally, a subsystem or system may include a platform with high-speed processing and software as a standalone tool or a networking tool.
[0042] Processor 130 may be located in or otherwise part of system 100 or another device. In the example, processor 130 may be part of a separate control unit or located in a centralized quality control unit. Multiple processors 130 may be used to define multiple subsystems of system 100.
[0043] In practice, processor 130 can be implemented by any combination of hardware, software, and firmware. Furthermore, its functions, as described herein, can be performed by a single unit or divided among different components, each of which can be implemented by any combination of hardware, software, and firmware. Program code or instructions for processor 130 to perform various methods and functions can be stored in a readable storage medium, such as memory.
[0044] If system 100 comprises more than one subsystem, then different processors 130 can be coupled to each other, allowing images, data, information, instructions, etc., to be transmitted between the subsystems. For example, a subsystem can be coupled to an additional subsystem via any suitable transmission medium, which may include any suitable wired and / or wireless transmission medium known in the art. Two or more of such subsystems can also be effectively coupled by sharing a computer-readable storage medium (not shown).
[0045] Processor 130 can be configured to perform various functions using the output of system 100 or other outputs. For example, processor 130 can be configured to send outputs to an electronic data storage unit or another storage medium. Processor 130 can be further configured as described herein.
[0046] Processor 130 may be configured according to any of the embodiments described herein. Processor 130 may also be configured to perform other functions or additional steps using the output of system 100 or using images or data from other sources.
[0047] Processor 130 can be communicatively coupled to any of the various components or subsystems of system 100 in any manner known in the art. Furthermore, processor 130 can be configured to receive and / or acquire data or information (e.g., inspection results from an inspection system such as a re-inspection tool, a remote database containing design data, etc.) from other systems via a transmission medium that may include wired and / or wireless portions. In this way, the transmission medium can act as a data link between processor 160 and other subsystems of system 100 or systems external to system 100. The various steps, functions, and / or operations of system 100 and methods disclosed herein are performed by one or more of the following: electronic circuits, logic gates, multiplexers, programmable logic devices, ASICs, analog / digital controllers / switches, microcontrollers, or computing systems. Program instructions implementing methods such as those described herein can be transmitted or stored on a carrier medium. The carrier medium may include storage media such as read-only memory, random access memory, magnetic disk or optical disk, non-volatile memory, solid-state memory, magnetic tape, etc. The carrier medium may include a transmission medium, such as a wire, cable, or wireless transmission link. For example, the various steps described throughout this disclosure may be implemented by a single processor 130 (or computer subsystem) or alternatively by multiple processors 130 (or multiple computer subsystems). Moreover, different subsystems of system 100 may include one or more computing or logic systems. Therefore, the above description should not be construed as a limitation of this disclosure but is merely illustrative.
[0048] The sensitivity of ultrasound to defects can be estimated by the partial reflection intensity at the interface between the defect and the medium. The interface reflectivity can be determined by the acoustic impedance of the two media. in and These are the intensities of the reflected acoustic signal and the incident acoustic signal, respectively. and These are the acoustic impedances of the two media forming the interface. The acoustic impedance can be determined by the following formula: Where c is the speed of sound in the medium, and It refers to the density of the material. For example:
[0049]
[0050] Resolution can be proportional to the wavelength of the sound wave. For example, and Sensitivity (i.e., the detectability of the void) is proportional to the intensity of the reflected wave and depends to a minimum on the material:
[0051] Applicable to almost any material .
[0052] Embodiments of this disclosure provide a method 200, such as Figure 1A As shown in [the diagram]. The system 100 used in conjunction with method 200 is shown in [the diagram]. Figure 1B and 1C Method 200 may include the following steps.
[0053] At step 210, the ultrasonic transducer is attached to the substrate. In some embodiments, the substrate may include silicon, glass, ceramic, or an organic material. The ultrasonic transducer may be directly attached to the substrate. In other embodiments, the substrate may be a printed circuit board containing metal lines (e.g., made of copper or other conductive materials). The ultrasonic transducer may be attached to the metal lines of the printed circuit board. In some embodiments, the ultrasonic transducer may be indirectly attached to the substrate, for example, by means of an intermediary disposed between the ultrasonic transducer and the substrate. The intermediary may be a liquid, a gel, or other material having a similar impedance to the substrate.
[0054] At step 220, the ultrasonic detector is attached to the substrate. In some embodiments, the ultrasonic detector may be attached to the substrate (e.g., remotely from the ultrasonic transducer) Figure 1C (As shown in the figure). In other embodiments, the ultrasonic detector may be attached to the substrate (e.g., at the same location as the ultrasonic transducer). Figure 1B (As shown in the illustration). In some embodiments, the ultrasonic detector may be indirectly attached to the substrate, for example, by means of an intermediary disposed between the ultrasonic detector and the substrate. The intermediary may be a liquid, a gel, or other material having similar impedance to the substrate. In some embodiments, an ultrasonic transducer may also be used as an ultrasonic detector based on careful timing control between acoustic signal generation and detection.
[0055] At step 230, the processor controls the ultrasonic transducer to generate an acoustic signal applied to the substrate. The frequency of the acoustic signal can be in the range of tens of MHz or up to several GHz. Since the ultrasonic transducer is attached to the substrate, the acoustic signal generated by the ultrasonic transducer can travel through the substrate and be reflected by the substrate.
[0056] At step 240, the processor receives the reflected acoustic signal detected by the ultrasonic detector. Since the ultrasonic detector is attached to the substrate, acoustic signals traveling through the substrate or reflected by the substrate can be detected by the ultrasonic detector.
[0057] At step 250, the processor determines defects in the substrate based on a comparison of the phase and intensity of the reflected acoustic signal with the acoustic signal applied to the substrate. For example, defects present in the substrate can cause changes in the intensity of the acoustic signal (e.g., in...). Figure 1B The strength is increased in the arrangement shown in the figure, and in Figure 1CThe arrangement shown may result in reduced strength and / or a phase shift in the acoustic signal. Therefore, defects in the substrate can be identified by comparing the acoustic signal applied to the substrate by the ultrasonic transducer with the reflected acoustic signal detected by the ultrasonic detector. Such defects may include voids or cracks in the substrate, cracks in the metal lines of the PCB, or gaps between repaired segments of the metal lines of the PCB.
[0058] Another embodiment of this disclosure provides a method 300, such as Figure 2A As shown in [the diagram]. System 100a, used in conjunction with method 300, is shown in [the diagram]. Figure 2B The difference between system 100a and system 100 is that the ultrasonic transducer 110 is a multi-segment ultrasonic transducer, wherein each segment is configured to emit an acoustic signal. Additionally, system 100a is applied to a chip 103 disposed on a substrate 101, and an underfill material 104 may be disposed between the chip 103 and the substrate 101. Method 300 may include the following steps.
[0059] At step 310, the multi-segment ultrasonic transducer is attached to the chip. The chip may be disposed on a substrate, with an underfill material disposed between the chip and the substrate. In some embodiments, the multi-segment ultrasonic transducer may be indirectly attached to the chip, for example, by means of an intermediary disposed between the multi-segment ultrasonic transducer and the chip. The intermediary may be a liquid, a gel, or other material having a similar impedance to the chip.
[0060] At step 320, an ultrasonic detector is attached to the chip. In some embodiments, the ultrasonic detector may be attached to the chip remotely from the multi-segment ultrasonic transducer. In other embodiments, the ultrasonic detector may be attached to the chip at the same location as the multi-segment ultrasonic transducer. In some embodiments, the ultrasonic detector may be integrated with the multi-segment ultrasonic transducer as a single device. In some embodiments, the ultrasonic detector may be indirectly attached to the chip, for example, by means of an intermediary disposed between the ultrasonic detector and the chip. The intermediary may be a liquid, a gel, or other material having a similar impedance to the chip. In some embodiments, some or all of the segments of the multi-segment ultrasonic transducer may also be used as the ultrasonic detector, based on careful timing control between acoustic signal generation and detection.
[0061] At step 330, the processor controls the multi-segment ultrasonic transducer to generate acoustic signals applied to the chip from each segment. The frequency of the acoustic signals can range from tens of MHz to several GHz. The processor can be configured to individually control each segment of the multi-segment ultrasonic transducer, which allows the acoustic signals to be focused onto specific portions of the chip by controlling specific segments or groups of segments, and allows the acoustic signals to be scanned by sequentially controlling one or more segments across the chip. Because the multi-segment ultrasonic transducer is attached to the chip, the acoustic signals generated by the multi-segment ultrasonic transducer can travel through the chip, underfill material, and substrate, and can be reflected by the chip, underfill material, and substrate. The acoustic signals from each segment of the multi-segment ultrasonic transducer can have a phase delay between segments. The phase delay of the acoustic signals from each segment of the multi-segment ultrasonic transducer can focus the sound waves at different depths relative to the chip.
[0062] At step 340, the processor receives the reflected acoustic signal detected by the ultrasonic detector. Since the ultrasonic detector is attached to the chip, acoustic signals traveling through the chip, underfill material, or substrate, or reflected by the chip, underfill material, or substrate, can be detected by the ultrasonic detector.
[0063] At step 350, the processor determines defects in the underfill material based on the phase delay and intensity of the reflected acoustic signal. For example, defects / voids in the underfill material can cause an increase in the intensity of the acoustic signal and / or a phase shift due to the high impedance difference between the underfill material and air. The phase shift of the reflected acoustic signal can correspond to a specific segment of a multi-segment ultrasonic transducer. Therefore, defects in the underfill material can be identified by comparing the acoustic signal applied to the chip by the multi-segment ultrasonic transducer with the reflected acoustic signal detected by the ultrasonic detector.
[0064] Another embodiment of this disclosure provides a method 400, such as Figure 3A The system 100b used in conjunction with method 400 is shown in [the diagram]. Figure 3B The difference between system 100b and system 100 is that, instead of ultrasonic detector 120, system 100b includes a laser source 140 and a laser detector 145. The ultrasonic detector 120 is arranged close to a first side 101a of the substrate, while the laser source 140 is configured to emit laser light toward a second side 101b of the substrate 101, and the laser detector 145 is configured to detect laser light reflected by the second side 101b of the substrate 101. The laser source 140 may be a laser diode (continuous wave or modulated), and the laser detector 145 may be a photodiode. In some embodiments, the laser detector 145 may be a pixelated detector. Method 400 may include the following steps.
[0065] At step 410, the ultrasonic transducer is positioned close to a first side of the substrate. In some embodiments, the substrate may include silicon, glass, ceramic, or an organic material. In other embodiments, the substrate may be a printed circuit board containing metal lines (e.g., made of copper or other conductive materials).
[0066] At step 420, the processor controls the ultrasonic transducer to generate an acoustic signal applied to the substrate. The frequency of the acoustic signal can be in the range of tens of MHz or up to several GHz. The acoustic signal generated by the ultrasonic transducer can be directed toward a first side of the substrate and can be reflected by the first side of the substrate.
[0067] At step 430, the laser source scans across a second side of the substrate with a laser beam. The second side may be opposite the first side. The laser beam may be a spot laser or a line. The scanning may be performed, for example, using a movable stage, scanning mirror, or other components by moving the substrate.
[0068] At step 440, the detector detects the reflected laser beam. The reflected laser beam may be a reflection of a laser beam from a second side of the substrate.
[0069] At step 450, the processor determines a defect in the substrate based on changes in the phase and amplitude of the reflected laser beam received from the detector. For example, a defect in the substrate may cause a reduction in the amplitude of the reflected laser beam detected by the detector and / or may cause a phase shift in the reflected laser beam detected by the detector. Therefore, as the laser beam scans across the second side of the substrate, changes in the reflected laser beam can indicate a defect, and the location of the defect can be identified based on the scan position.
[0070] Another embodiment of this disclosure provides a method 500, such as Figure 4A As shown in [the diagram]. System 100c, used in conjunction with method 500, is shown in [the diagram]. Figure 4B The difference between system 100c and system 100 is that substrate 101 is a solid-state battery, and ultrasonic transducer 110 and ultrasonic detector 120 are positioned close to substrate 101 but not attached to it. However, in some embodiments, ultrasonic transducer 110 and ultrasonic detector 120 may be indirectly attached to substrate 101 via an intermediary such as a liquid, gel, or other material having an acoustic impedance similar to that of substrate 101. Method 500 may include the following steps.
[0071] At step 510, the ultrasonic transducer and ultrasonic detector are positioned close to the substrate. The ultrasonic transducer and ultrasonic detector may be part of the same device. In some embodiments, the substrate may be a solid-state battery. In some embodiments, the ultrasonic transducer may also be used as an ultrasonic detector based on careful timing control between acoustic signal generation and detection.
[0072] At step 520, the processor controls the ultrasonic transducer to emit sound waves toward the substrate. The frequency of the acoustic signal can be in the range of tens of MHz or up to several GHz. The sound waves can be reflected by the substrate and received by the ultrasonic detector.
[0073] At step 530, the substrate is scanned relative to the ultrasonic transducer and ultrasonic detector. For example, the substrate may be placed on a stage that is movable relative to the ultrasonic transducer and ultrasonic detector. Alternatively, the ultrasonic transducer and ultrasonic detector may be movable relative to the substrate.
[0074] At step 540, while the substrate is being scanned, the processor can determine defects in the substrate based on changes in the phase or intensity of the reflected acoustic signal detected by the ultrasonic detector. For example, due to the high impedance difference between the substrate and air, defects in the substrate can cause a decrease in the intensity of the reflected acoustic signal and / or an change in the phase of the reflected acoustic signal received by the ultrasonic detector. Therefore, when the substrate is scanned relative to the ultrasonic transducer and the ultrasonic detector, changes in the reflected acoustic signal can indicate defects, and the location of the defects can be identified based on the scan position. In some embodiments, the defect may be a crack or dendrite protrusion in the solid-state battery.
[0075] Following methods 200, 300, 400, or 500 of this disclosure, the detected defects can be repaired. For example, when an additive process is used to repair open voids or crack defects 102 in substrate 101 (e.g., laser-induced forward transfer (LIFT), inkjet printing, etc.), acoustic signals from the ultrasonic transducer 110 can be used to improve the adhesion of the additive material 105 to substrate 101 or to improve material properties. Figure 5A and 5B As shown, the ultrasonic transducer 110 can be positioned close to the additive material 105 and can apply an acoustic signal until the material in the defect 102 is aligned with the substrate 101. Alternatively, when adding solder bumps to correct defects in the metal traces of a PCB, the acoustic signal from the ultrasonic transducer can be used to melt or sinter the solder bumps, allowing solder material to reflow and repair deformed or low-solder bumps. Figure 6A and 6BAs shown, solder material is deposited from solder source 150 to form solder bumps 106. When the solder bumps deform or become low, they can be defects 102. By applying an acoustic signal to the solder bumps 106, the solder can be melted and reformed into a corrected shape. In some embodiments, voids or defects 102 in the substrate 101 can be bubbles 107 between layers of the substrate 101. Figures 7A to 7C As shown, by applying an acoustic signal from the ultrasonic transducer 110 to the substrate 101 or scanning the substrate 101 or the ultrasonic transducer 110, a bubble 107 can be pushed out of the substrate 101 to correct the defect 102. In either of the repair processes, the processor can use the location of the defect detected in the substrate to control the location where the acoustic signal is applied to the substrate to repair the defect, thus avoiding damage to the substrate in locations where the defect is not detected. The frequency of the acoustic signal generated by the ultrasonic transducer may differ during the repair process from the frequency used during the detection process. For example, the frequency of the acoustic signal generated by the ultrasonic transducer may be higher during the repair process than the frequency used during the detection process.
[0076] In an embodiment, method 200 may further include step 260, such as Figure 1A As shown in the diagram. At step 260, the processor controls the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair it. For example, the defect could be a void or crack in the substrate, and after the void or crack is filled with an additive material, the acoustic signal can improve the adhesion or material properties of the additive material, such as… Figure 5A and 5B As shown in the image.
[0077] In another embodiment, method 200 may further include step 270, such as Figure 1A As shown in the diagram. At step 270, solder material is deposited onto the defect in the substrate to repair the defect. For example, the defect may be a crack in a metal wire, and the solder material may fill the crack to repair the defect. In some embodiments, the defect in the substrate may be a gap between repaired segments of a metal wire, and the solder material may fill the gap to repair the defect. If the applied solder bumps deform or become lower, the processor may further control an ultrasonic transducer to apply an acoustic signal to melt or sinter the solder bumps, such as... Figure 6A and 6B As shown in the image.
[0078] In some embodiments, after step 260 or step 270, steps 230 to 250 may be repeated to verify that no defects remain after the repair process or whether further repair is required.
[0079] In another embodiment, method 300 may further include step 360, such as Figure 2AAs shown in the diagram. At step 360, the processor controls a multi-segment ultrasonic transducer to generate an acoustic signal from at least one segment to apply to the defect in the underfill material to repair the defect. For example, the multi-segment ultrasonic transducer may generate an acoustic signal from at least one segment based on the location of the defect determined by the processor, and the acoustic signal applied to the defect may be configured to melt or sinter the underfill material to repair the defect. In some embodiments, after step 360, steps 330 to 350 may be repeated to verify that no defect remains after the repair process or whether further repair is required.
[0080] In another embodiment, method 400 may further include steps 460 and 470, such as Figure 3A As shown in the diagram. At step 460, the substrate is scanned relative to the ultrasonic transducer to position the ultrasonic transducer close to a defect in the substrate. The ultrasonic transducer can be positioned close to a defect in the substrate to avoid damaging areas of the substrate that have not been identified as defects. At step 470, the processor controls the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair the defect. For example, the defect can be a void or crack in the substrate, and after the void or crack is filled with an additive material, the acoustic signal can improve the adhesion or material properties of the additive material, such as... Figure 5A and 5B As shown in the figure. In some embodiments, after step 470, steps 420 to 450 may be repeated to verify that no defects remain after the repair process or whether further repair is required.
[0081] In another embodiment, method 500 may further include steps 550 and 560, such as Figure 4A As shown in the diagram. At step 550, the substrate is scanned relative to the ultrasonic transducer to locate the ultrasonic transducer close to a defect in the substrate. The ultrasonic transducer can be located close to a defect in the substrate to avoid damaging areas of the substrate that have not been identified as defects. At step 560, the processor controls the ultrasonic transducer to emit acoustic waves applied to the defect in the substrate to repair the defect. For example, the defect may be a crack or dendrite protrusion in a solid-state battery, and after the crack or dendrite protrusion is filled with an additive material, the acoustic waves may improve the adhesion or material properties of the additive material, such as… Figure 5A and 5B As shown in the figure. In some embodiments, after step 560, steps 520 to 540 may be repeated to verify that no defects remain after the repair process or whether further repair is required.
[0082] Using methods 200, 300, 400, and 500 of this disclosure, defects in various types of substrates can be detected using ultrasound, and these defects can be repaired using ultrasound. Ultrasonic detection can be used for optically opaque materials. Furthermore, due to the variability of the velocity and frequency of the applied acoustic signal, ultrasonic detection improves detection resolution compared to other methods. Therefore, the detection method can improve overall production yield.
[0083] Although this disclosure has been described with respect to one or more specific embodiments, it should be understood that other embodiments of this disclosure may be made without departing from the scope of this disclosure. Therefore, this disclosure is to be considered limited only by the appended claims and their reasonable interpretation.
Claims
1. A method comprising: Attach the ultrasonic transducer to the substrate; Attach the ultrasonic detector to the substrate; The processor controls the ultrasonic transducer to generate an acoustic signal applied to the substrate; The processor receives the reflected acoustic signal detected by the ultrasonic detector; and The processor determines defects in the substrate by comparing the phase and intensity of the reflected acoustic signal with the acoustic signal applied to the substrate.
2. The method of claim 1, wherein the substrate comprises silicon, glass, ceramic or organic material, and the defect is a void or crack in the substrate.
3. The method of claim 1, wherein the substrate comprises a printed circuit board.
4. The method of claim 3, wherein the ultrasonic transducer is attached to a metal line of the printed circuit board, and the ultrasonic detector is attached to the metal line, and the defect in the substrate is a crack in the metal line.
5. The method of claim 3, wherein the ultrasonic transducer is attached to a metal line on the printed circuit board, and the ultrasonic detector is attached to the metal line, and the defect in the substrate is a gap between repaired segments of the metal line.
6. The method of claim 1, wherein the ultrasonic detector is attached to the substrate remotely from the ultrasonic transducer.
7. The method of claim 1, wherein the ultrasonic detector is attached to the substrate at the same location as the ultrasonic transducer.
8. The method of claim 1, further comprising: The processor controls the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair the defect.
9. The method of claim 1, further comprising: The defect is repaired by depositing welding material into the substrate.
10. A method comprising: A multi-segment ultrasonic transducer is attached to a chip, wherein the chip is disposed on a substrate, and an underfill material is disposed between the chip and the substrate. Attach the ultrasonic detector to the chip; The processor controls the multi-segment ultrasonic transducer to generate an acoustic signal applied to the chip from each segment, wherein the acoustic signal from each segment of the multi-segment ultrasonic transducer has a phase delay. The processor receives the reflected acoustic signal detected by the ultrasonic detector; and The processor uses the phase and intensity of the reflected acoustic signal to determine defects in the underfill material.
11. The method of claim 10, wherein the phase delay of the acoustic signal from each segment of the multi-segment ultrasonic transducer focuses the acoustic wave at a different depth relative to the chip, such that the acoustic wave is reflected by the underfill material and detected by the ultrasonic detector.
12. The method of claim 10, further comprising: The processor controls the multi-segment ultrasonic transducer to generate acoustic signals from at least one segment, which are applied to the defect in the underfill material to repair the defect.
13. The method of claim 12, wherein the acoustic signal applied to the defect is configured to melt or sinter the underfill material to repair the defect.
14. A method comprising: Position the ultrasonic transducer close to the first side of the substrate; The processor controls the ultrasonic transducer to generate an acoustic signal applied to the substrate; A laser source is used to scan across a second side of the substrate, wherein the first side is opposite to the second side; The reflected laser beam is detected by a detector, wherein the reflected laser beam is the laser beam reflected from the second side of the substrate; and The processor determines defects in the substrate based on phase and amplitude changes in the reflected laser beam received from the detector.
15. The method of claim 14, further comprising: The processor controls the ultrasonic transducer to generate an acoustic signal applied to the defect in the substrate to repair the defect.
16. The method of claim 15, wherein before controlling the ultrasonic transducer with the processor to generate an acoustic signal applied to the defect in the substrate to repair the defect, the method further comprises: The substrate is scanned relative to the ultrasonic transducer to position the ultrasonic transducer close to the defect in the substrate.
17. A method comprising: The ultrasonic transducer and ultrasonic detector are positioned close to the substrate; The processor controls the ultrasonic transducer to emit sound waves toward the substrate, wherein the sound waves are reflected by the substrate and received by the ultrasonic detector. The substrate is scanned relative to the ultrasonic transducer and the ultrasonic detector; and The processor determines defects in the substrate based on changes in the phase or intensity of the reflected sound waves detected by the ultrasonic detector during scanning of the substrate.
18. The method of claim 17, wherein the substrate is a solid-state battery, and the defect is a crack or dendritic protrusion in the solid-state battery.
19. The method of claim 17, further comprising: The processor controls the ultrasonic transducer to emit acoustic waves applied to the defect in the substrate to repair the defect.
20. The method of claim 19, wherein before controlling the ultrasonic transducer with the processor to emit acoustic waves applied to the defect in the substrate to repair the defect, the method further comprises: The substrate is scanned relative to the ultrasonic transducer to position the ultrasonic transducer close to the defect in the substrate.