A method and device for appearance detection of LED chip integrated die bonding

Abstract

The application provides an appearance detection method and device for LED chip integration and die bonding. The method comprises the following steps: transferring a target LED chip from a blue film to a target substrate to realize die bonding; collecting die bonding image information of one or more first target visual fields during the die bonding transfer process, the die bonding image information has a first resolution, and the first target visual field is from a die bonding machine platform, and the die bonding machine platform comprises the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip; and obtaining appearance detection information of the target LED chip based on the die bonding image information. The resolution of the die bonding image information is improved, the first target visual field is enlarged, and the target chip and the adjacent chip are analyzed and compared, so that the die bonding quality of the LED chip can be monitored in real time, it is detected whether the die bonding is abnormal, an alarm is given in time for processing once the die bonding is abnormal, the placement position of the next target LED chip is corrected, the rework rate is greatly reduced, and the die bonding yield and the production efficiency are improved.

Description

Technical Field

[0001] This invention belongs to the field of LED chip integration testing, and more specifically, relates to a method and apparatus for appearance testing of LED chip integration die bonding. Background Technology

[0002] Currently, the appearance inspection of traditional LED chip integration die bonding is mainly carried out on two separate devices: a die bonding machine and an AOI machine. Specifically, the existing die bonding machine is used to transfer the LED chip from the blue film to the target substrate. Then, the AOI machine is used to perform appearance inspection on the LED chip on the substrate after die bonding and outputs a document containing records of appearance yield and marking the location of defective chips for subsequent rework.

[0003] In other words, existing die bonders simply transfer LED chips repeatedly. Whether the placement of each LED chip meets the requirements is analyzed by a dedicated AOI machine after all LED chips have been transferred. This means that the quality of die bonding cannot be fed back in real time, resulting in high rework rates, low production efficiency, and high costs. In addition, current die bonders mainly transfer LED chips to the target chip, serving only a simple positioning function. They lack re-inspection capabilities, resulting in limited detection of abnormal states and an inability to achieve appearance inspection and evaluation that meets process requirements.

[0004] In addition, the abbreviations mentioned above are specifically:

[0005] LED (Light Emitting Diode): A light-emitting diode;

[0006] AOI (Automatic Optic Inspection): Automated optical inspection;

[0007] CCD (Charge Coupled Device): A device that converts optical images into digital signals. Summary of the Invention

[0008] To address at least one of the defects or improvement needs of the existing technology, the present invention provides an appearance inspection method and apparatus for LED chip integrated die bonding, which solves the problems of traditional LED chip integrated die bonding appearance inspection, such as the inability to provide real-time feedback on die bonding quality, limited feedback on die bonding status, high rework rate, low production efficiency, and high cost.

[0009] To achieve the above objectives, the present invention provides a method and apparatus for appearance inspection of LED chip integrated die bonding, the method comprising:

[0010] The target LED chip is transferred from the blue film to the target substrate to achieve die bonding;

[0011] As the die bonding transfer process proceeds, die bonding image information of one or more first target fields of view is acquired. The die bonding image information has a first resolution, and the first target field of view includes the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip.

[0012] Based on the die-bonding image information, the appearance inspection information of the target LED chip is obtained;

[0013] The first target field of view comes from a die bonding machine platform.

[0014] Furthermore, the analysis includes comparing one or more of the relative positions, shapes, and grayscale steps of the target LED chip and the adjacent LED chips in the first target field of view.

[0015] Furthermore, obtaining the appearance inspection information of the target LED chip includes:

[0016] Based on the target LED chip and the adjacent LED chips, determine whether the appearance of the target LED chip is abnormal:

[0017] If an anomaly is detected, an alarm is issued, the anomaly information is recorded, and an appearance anomaly file is output. After correction, the process continues to move to the next target LED chip.

[0018] If everything is normal, continue transferring to the next target LED chip.

[0019] Furthermore, the first target field of view includes the target LED chip and four adjacent LED chips that are evenly spaced around the outer periphery of the target LED chip.

[0020] Furthermore, the first resolution is greater than or equal to 20 megabits.

[0021] In another aspect of the present invention, an appearance inspection device for LED chip integrated die bonding is also provided, the device comprising:

[0022] Die bonding platform: used to transfer the target LED chip from the blue film onto the target substrate;

[0023] Optical acquisition component: having a first resolution, used to acquire die-bonding image information of one or more first target fields of view on the die-bonding machine platform, the first target field of view including the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip;

[0024] Analysis module: Receives the die-bonding image information and analyzes it to obtain the appearance inspection information of the target LED chip.

[0025] Furthermore, the first resolution parameter is greater than or equal to 20 megabits.

[0026] Furthermore, the first target field of view includes the target LED chip and four adjacent LED chips that are evenly spaced around the outer periphery of the target LED chip.

[0027] Furthermore, the optical acquisition component is disposed inside the die-bonding platform.

[0028] Furthermore, the analysis module is located inside the optical acquisition component or the die bonder platform;

[0029] or,

[0030] The analysis module is located outside the optical acquisition component or the die bonder platform.

[0031] In general, the technical solution conceived in this invention can achieve the following beneficial effects compared with the prior art:

[0032] (1) The present invention provides an appearance inspection method and device for integrated die bonding of LED chips. During the die bonding transfer process, high-resolution die bonding image information is collected, which can monitor the die bonding quality of LED chips in real time. Once an abnormality occurs, an alarm can be triggered in time for processing, which greatly reduces the rework rate, improves the die bonding yield, and also improves production efficiency and reduces rework costs to a certain extent.

[0033] (2) The present invention provides an appearance inspection method and apparatus for LED chip integrated die bonding, which expands the first target field of view to include the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip, thereby increasing the field of view. By analyzing and comparing the target chip and the adjacent chip, it is possible to more clearly detect whether there are abnormal states such as missing parts, offset, side-standing, stacking, foreign objects, etc. in the die bonding. It can not only monitor the quality of die bonding in time and mark the defective positions of die bonding, but also make it easier to correct the placement position of the next target LED chip, reduce the fault tolerance rate, and thus improve the die bonding yield and production efficiency. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic flowchart of an LED chip integrated die bonding appearance inspection method and apparatus according to the present invention;

[0036] Figure 2 This is a schematic diagram of the first target field of view of the appearance inspection method and apparatus for LED chip integrated die bonding according to the present invention. Figure 1 ;

[0037] Figure 3 This is a schematic diagram of the first target field of view of the appearance inspection method and apparatus for LED chip integrated die bonding according to the present invention. Figure 2 . Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0039] The terms "first," "second," "third," and "fourth" in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0040] Figure 1 This is a schematic flowchart of a method and apparatus for appearance inspection of LED chip integrated die bonding according to the present invention. Specifically:

[0041] First, the target LED chip is transferred from the blue film to the target substrate to achieve die bonding;

[0042] Then, during the die bonding transfer process, die bonding image information of one or more first target fields of view is acquired, wherein the die bonding image information has a first resolution, and the first target field of view includes the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip, and the first target field of view comes from a die bonding machine platform.

[0043] Finally, based on the die-bonding image information analysis, the appearance inspection information of the target LED chip is obtained.

[0044] In other words, the die-bonding image information is acquired during the die-bonding transfer process. Each time the target LED chip is transferred from the blue film to the target substrate, die-bonding image information is acquired and analyzed to obtain the appearance inspection information of the target LED chip. It should be noted that die-bonding can transfer one target LED chip at a time, or multiple target LED chips can be transferred simultaneously; the acquisition of die-bonding image information can be one first target field of view of one target LED chip, or multiple first target fields of view of one target LED chip; it can also be one first target field of view of multiple target LED chips, or multiple first target fields of view of multiple target LED chips.

[0045] However, regardless of the circumstances, it is essential to ensure that the die-bonding image information has a first resolution, and that the first target field of view includes the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip. As an embodiment of the present invention, the first resolution is greater than or equal to 20 megahertz, and the first target field of view includes the target LED chip and four complete adjacent LED chips adjacent to the target LED chip.

[0046] As an embodiment of the present invention, when die bonding image information is acquired once for each target LED chip transferred sequentially during the die bonding transfer process, the schematic diagram of the first target field of view is shown below. Figure 1 like Figure 2 As shown, the first target field of view includes the target LED chip (target-1) and four complete neighboring LED chips (neighbor-1-1, neighbor-1-2, neighbor-1-3, and neighbor-1-4).

[0047] As more and more target LED chips are transferred onto the target substrate during the die-bonding process, the system not only collects die-bonding image information of the target LED chips being transferred at that time, but also collects die-bonding image information of previously transferred target LED chips to further detect any abnormalities in chip placement and appearance. For example... Figure 3 The diagram shown illustrates the first target field of view of the appearance inspection method and apparatus for LED chip integrated die bonding according to the present invention. Figure 2 The first target field of view includes the target LED chip (target-2) and four complete adjacent LED chips (adjacent 2-2, adjacent 2-4, adjacent 2-5, adjacent 2-7) evenly spaced around the outer periphery of the target LED chip.

[0048] Finally, based on the die-bonding image information of the first target field of view, the appearance inspection information of the target LED chip is analyzed and obtained, and the placement position of the next target LED chip is corrected based on the appearance inspection information.

[0049] As an embodiment of the present invention, obtaining the appearance inspection information of the target LED chip includes: determining whether the appearance of the target LED chip is abnormal based on the target LED chip and adjacent LED chips. As a preferred embodiment of the present invention, the chip is detected to be in an abnormal state by comparing one or more of the relative position, shape, and grayscale step of the target LED chip and adjacent LED chips in the first target field of view. For example, comparing target-1 with adjacent 1-1, adjacent 1-2, adjacent 1-3, and adjacent 1-4, if the relative position offset of target-1 exceeds a set parameter, or the shape is different from adjacent 1-1, adjacent 1-2, adjacent 1-3, and adjacent 1-4, or the grayscale step exceeds the set parameter, then it means that the state of target-1 at this time is abnormal, and it is marked as (target-1, missing part / offset / sideways / overlapping crystal / foreign object).

[0050] If an anomaly is detected, an alarm is issued, an anomaly information is recorded, and an appearance anomaly file is output. After correction, the process continues to move to the next target LED chip. Using target-1 and neighboring LEDs 1-1, 1-2, 1-3, and 1-4 as examples, if target-1 has an anomaly, an alarm is issued, an anomaly information is recorded, and output is made. The output format is not limited; it can be an image or a document. Furthermore, issuing the alarm will simultaneously stop die bonding and stop acquiring die bonding image information. At this time, the die bonding machine will adjust based on the anomaly status or notify the operator to handle the anomaly. Once everything is normal, the die bonding process and the acquisition of die bonding image information will resume. It should be noted that the die bonding machine adjusts based on the anomaly status to correct the placement of the next target LED chip.

[0051] If everything is normal, continue transferring to the next target LED chip.

[0052] In summary, by improving the resolution of die-bonding image information and expanding the field of view of the first target, this invention analyzes and compares the target chip and adjacent chips, enabling real-time monitoring of the die-bonding quality of LED chips. It can clearly detect abnormal states such as missing components, misalignment, side-standing, stacking, and foreign objects in the die-bonding process. Once an abnormality occurs, an alarm can be triggered in time for processing, and the placement position of the next target LED chip can be corrected, thereby greatly reducing the rework rate and improving the die-bonding yield and production efficiency.

[0053] As another aspect of the present invention, an appearance inspection device for LED chip integrated die bonding is also provided, the device comprising:

[0054] A die bonder platform is used to transfer target LED chips from the blue film onto the target substrate.

[0055] An optical acquisition component, having a first resolution, is used to acquire die-bonding image information of one or more first target fields of view on a die-bonding machine platform. The first target field of view includes a target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip.

[0056] The analysis module receives die-bonding image information and analyzes it to obtain the appearance inspection information of the target LED chip.

[0057] In a preferred embodiment of the present invention, the optical acquisition component is disposed inside the die bonding platform. The optical acquisition component can be a CCD with a first resolution. By modifying the die bonding machine platform, the optical acquisition component CCD can take pictures and detect the placement of the target LED chip after each transfer. The appearance of the chip is judged by AOI algorithm according to the quality requirements, thus meeting the detection requirements of LED chip die bonding. In addition, there is no need to add an additional AOI machine for appearance inspection, saving costs.

[0058] As an embodiment of the present invention, the analysis module can be set not only inside the optical acquisition component or the die bonder platform, but also outside the optical acquisition component or the die bonder platform to perform offline analysis or online remote analysis. This allows it to monitor the die bond quality of the LED chip in real time, and to promptly alarm and handle any abnormalities, greatly reducing the rework rate and improving the die bond yield.

[0059] In addition, the principle and technical effect of an LED chip integrated die bonding appearance inspection device are similar to some of the technical features of the above-mentioned LED chip integrated die bonding appearance inspection method, and will not be repeated here.

[0060] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0061] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0062] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0063] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0064] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0065] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0066] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0067] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This invention is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for visual inspection of LED chip integrated die bonding, characterized in that, The method includes: Each time the target LED chip is transferred from the blue film to the target substrate to achieve die bonding, a die bonding image information of the target LED chip is acquired. As the die bonding process is carried out, die bonding image information of one or more first target fields of view is acquired during the die bonding transfer process. The die bonding image information has a first resolution and amplifies the first target fields of view. The first target fields of view include the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip. Based on the die-bonding image information analysis, the appearance detection information of the target LED chip is obtained, including: determining whether the appearance of the target LED chip is abnormal based on the target LED chip and the adjacent LED chip; if the appearance of the target LED chip is determined to be abnormal, an alarm is issued and die bonding and the acquisition of die-bonding image information are stopped; after the abnormality is handled, the die bonding process and the acquisition of die-bonding image information are resumed. The first target field of view comes from a die bonding machine platform.

2. The appearance inspection method for LED chip integrated die bonding as described in claim 1, characterized in that, The analysis includes comparing one or more of the relative position, shape, and grayscale step of the target LED chip and the adjacent LED chip in the first target field of view.

3. The method for appearance inspection of LED chip integrated die bonding as described in any one of claims 1 to 2, characterized in that, Obtaining the appearance inspection information of the target LED chip includes: Based on the target LED chip and the adjacent LED chips, determine whether the appearance of the target LED chip is abnormal: If an anomaly is detected, an alarm is issued, the anomaly information is recorded, and an appearance anomaly file is output. After correction, the process continues to move to the next target LED chip. If everything is normal, continue transferring to the next target LED chip.

4. The appearance inspection method for LED chip integrated die bonding as described in claim 1, characterized in that, The first target field of view includes the target LED chip and four adjacent LED chips that are evenly spaced around the outer periphery of the target LED chip.

5. The method for appearance inspection of LED chip integrated die bonding as described in claim 2, characterized in that, The first resolution is greater than or equal to 20 megabits.

6. An appearance inspection device for integrated die bonding of LED chips, characterized in that, The device includes: Die bonding platform: used to transfer the target LED chip from the blue film onto the target substrate; Optical acquisition component: having a first resolution, used to acquire die bonding image information of the target LED chip once each time the target LED chip is transferred from the blue film to the target substrate for die bonding; on the die bonding machine platform, during the die bonding transfer process, die bonding image information of one or more first target fields of view is acquired, and the first target fields of view are amplified; the first target fields of view include the target LED chip and at least one complete adjacent LED chip adjacent to the target LED chip; Analysis module: Receives the die-bonding image information and analyzes and obtains the appearance detection information of the target LED chip, including: determining whether the appearance of the target LED chip is abnormal based on the target LED chip and the adjacent LED chips; if the appearance of the target LED chip is determined to be abnormal, an alarm is issued and die bonding and the acquisition of die-bonding image information are stopped; after the abnormality is handled, the die bonding process and the acquisition of die-bonding image information are resumed.

7. The appearance inspection device for LED chip integrated die bonding as described in claim 6, characterized in that, The first resolution parameter is greater than or equal to 20 megabits.

8. The appearance inspection device for LED chip integrated die bonding as described in claim 7, characterized in that, The first target field of view includes the target LED chip and four adjacent LED chips that are evenly spaced around the outer periphery of the target LED chip.

9. The appearance inspection device for LED chip integrated die bonding as described in any one of claims 6 to 8, characterized in that, The optical acquisition component is located inside the die bonder platform.

10. The appearance inspection device for LED chip integrated die bonding as described in any one of claims 6 to 8, characterized in that, The analysis module is located inside the optical acquisition component or the die bonding platform; or, The analysis module is located outside the optical acquisition component or the die bonder platform.

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