Dam glue detection method

Abstract

The invention discloses a box dam glue detection method, and relates to the technical field of wafer coating, and the method comprises the following steps: S1, data acquisition: carrying out height data acquisition on the outer contour of box dam glue at set intervals h along the cross section direction of the box dam glue preset by a system; s2, data processing: sampling the collected data, taking the first height of a continuously rising sampling point as a1, and taking the tail sampling height of a continuously falling sampling point as an; s3, carrying out area summation; s4, qualification judgment: if the total area S is greater than a preset area, determining that the product is qualified; if the total area S is smaller than the preset area, it is unqualified, through the detection method for the cross section of the box dam glue, the area of the cross section of the box dam glue can be detected very accurately, rapidly and efficiently, and whether the gluing amount of the box dam glue meets the glue amount needed by design or not is judged according to the area of the cross section of the box dam glue.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer coating, and in particular relates to a dam glue detection method. Background Art

[0002] In wafer coating equipment, dam adhesive is a critical material for ensuring the stability of precision wafer coating processes. During wafer manufacturing, particularly in advanced packaging, chip integration, and functional coating applications, liquid materials must be applied to specific areas of the wafer surface. To prevent this liquid material from leaking and contaminating non-target areas and to ensure coating boundary accuracy, dam adhesive is used to pre-form a closed or semi-closed "dam" structure around the edges of the target area.

[0003] Dam adhesives used for wafer coating must meet the high-precision and high-cleanliness requirements of wafer manufacturing. They are typically single-component materials with moderate viscosity to ensure coating formability. After curing, they must exhibit excellent adhesion, high-temperature resistance, and chemical resistance. Furthermore, the dam adhesive must exhibit minimal shrinkage upon curing to prevent shrinkage that could cause the dam to deform or delaminate from the wafer surface, thereby impacting subsequent coating. In standard wafer manufacturing, the dam adhesive dosage accuracy requirements are relatively low, and minor deviations generally do not significantly impact final product quality. However, in high-precision wafer manufacturing, deviations in dam adhesive dosage can have devastating consequences. If the adhesive dosage is insufficient, or the dam height or thickness is insufficient, the liquid coating material can easily break through the dam and leak out, contaminating the functional areas of the chip and causing device failure. If the adhesive dosage is excessive, the dam may overextend the target area or overflow into non-target areas, resulting in insufficient coating space and contamination of the wafer surface, also leading to product failure.

[0004] According to the process requirements for high-precision wafer coating, the cross-sectional area of ​​the dam adhesive (a direct reflection of the adhesive volume) must be immediately inspected after application to ensure it is within the specified range. However, most current production lines lack this step, and problems caused by substandard dam adhesive are often not discovered until later in the process. Due to the extremely high manufacturing costs of high-precision wafers, scrapping substandard products at this stage would result in significant cost losses, increasing production costs and selling prices while also reducing production efficiency and market competitiveness. Summary of the Invention

[0005] The purpose of the present invention is to provide a dam glue detection method, which is intended to solve the problem of traditional dam glue.

[0006] In order to solve the above-mentioned technical problems, the purpose of the present invention is achieved as follows: A method for detecting dam glue comprises the following steps: S1: Data collection, along the cross-section direction of the dam glue preset by the system, the outer contour of the dam glue is height-measured at every set interval h. Data collection; ; The required number of sampling points and sampling interval h can be set according to the sampling accuracy requirements. Of course, the number of sampling points is also determined by the inherent hardware characteristics of the sampling device and the driving device used.

[0007] S2: Data processing, including sampling the collected data, taking the first height of the continuously rising sampling point as a1, and the last sampling height of the continuously descending sampling point as an; by taking the first height of the continuously rising sampling point as the sampling starting point of the cross section and the end of the continuously descending sampling point as the sampling end point, the outer contour of the cross section can be obtained as realistically as possible, avoiding the deviation of the cross section acquisition due to sampling interference, which will have an adverse effect on the accuracy of the final calculation.

[0008] S3: area summation, ,in, is the cross-sectional area between adjacent collection points, and S is the total area; when the collection points are dense enough, the arc surface of the outer contour between two adjacent collection points on the cross section of the dam glue can be approximated to a straight line segment, thereby approximating the cross section between the two adjacent collection points to a trapezoid, wherein the height collected the previous time is the upper base, the height collected the next time is the lower base, and the distance h between the two collection points is the height, then the trapezoidal formula can be used to calculate the size of the cross section of the area, and finally the cross sections of each area are accumulated to obtain the area of ​​the entire dam glue cross section, thereby reducing the difficulty of data collection and the complexity of calculation while being able to obtain the dam glue cross section area as accurately as possible, thereby reducing the amount of data processing by the processor, improving the detection speed, and reducing the performance requirements for the processor.

[0009] S4: Qualified: If the total area S is greater than the preset area, it is qualified; if the total area S is less than the preset area, it is unqualified. The cross-sectional total area S calculated in step S3 is compared with the system's preset area range to obtain the cross-sectional test result of the dam glue.

[0010] On the basis of the above scheme and as a preferred scheme of the above scheme: step S2 also includes a filtering step, which includes filtering one or more sample heights of sudden rise and fall Filtering steps. During the inspection process, the sampling values ​​on the main body of the dam glue basically tend to be steadily increasing or steadily decreasing. However, in the early stages of the inspection and near the end of the inspection, at the critical position between the dam glue and the wafer surface, the laser will produce obvious fluctuations near this position. In other words, the sampling height will rise or fall suddenly. Of course, when inspecting the main body of the dam glue, some factors may also cause a sudden rise or fall. Therefore, removing these obviously fluctuating collection points can make the cross-section obtained by the collection calculation as close as possible to the actual cross-section, thereby obtaining a more accurate glue coating amount.

[0011] On the basis of the above scheme and as the preferred scheme of the above scheme: Step S1 uses a laser rangefinder to measure the height of each collection point The laser rangefinder has a fast response speed and high ranging accuracy, making it easier to achieve fast and accurate height sampling.

[0012] Based on the above solution and as a preferred solution, the laser rangefinder is operated by pulse triggering. During each pulse triggering interval, the laser rangefinder moves laterally by a distance equal to a spacing h. The spacing h is the vertical distance between two adjacent sampling points.

[0013] Based on the above solution and as a preferred solution, step S4 further includes outputting and displaying the judgment result via a human-computer interaction device. Displaying and outputting the processing result via the human-computer interaction device facilitates staff access to the test results. This can be accomplished by displaying a warning color on the display, flashing, or adding audible and visual alarms.

[0014] Compared with the existing technology, the present invention has the outstanding and beneficial technical effect that: through the cross-section detection method of the dam glue of the present invention, the cross-section area of ​​the dam glue can be detected very accurately, quickly and efficiently, which is used as a basis for judging whether the amount of dam glue applied meets the design required amount of glue, thereby improving the quality and pass rate of the entire wafer product back-end process. Since the manufacturing cost of wafer products is high, the loss of defective products can be effectively reduced through detection and control of the front-end process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a data collection diagram of the dam glue detection position of the present invention. DETAILED DESCRIPTION

[0016] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the given embodiments, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0017] In the description of this application, it should be understood that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0018] In the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0019] The present invention discloses a dam glue detection method, which includes the following steps: S1: Data acquisition, along the cross-section direction of the dam glue preset by the system, the height of the outer contour of the dam glue is measured at every set interval h. Data collection; The number of sampling points and the sampling interval h can be set according to the sampling accuracy requirements. Of course, the number of sampling points is also determined by the inherent hardware characteristics of the sampling device and the driving device. The height of each sampling point is measured by a laser rangefinder in step S1. To collect data. The laser rangefinder has a fast response speed and high ranging accuracy, making it easier to achieve fast and accurate height sampling. The laser rangefinder operates in a pulse triggering manner. In the interval between each pulse triggering, the distance the laser rangefinder moves laterally is the spacing h, which is the vertical distance between two adjacent sampling points. It should be noted that in this embodiment, a transverse driving mechanism is preferably used to drive the laser rangefinder to move laterally along the section direction. During the pulse interval of the laser rangefinder, that is, after the current pulse ranging of the laser rangefinder is completed, the transverse driving mechanism drives the laser rangefinder to move laterally by the spacing h. After the transverse driving mechanism moves, the laser rangefinder performs the next height data collection until the preset transverse movement distance is reached. The transverse driving mechanism here can adopt a combination of a servo motor and a screw nut pair. A high-precision screw nut pair is used to reduce the backlash and movement error, which can effectively improve the transverse movement accuracy and help improve the detection accuracy. Furthermore, it should be noted that laser rangefinders operate using pulse triggering, a common laser operating mode. Its core principle is to control the energy release of the laser gain medium, causing it to output laser light in the form of short, high-intensity pulses. The laser medium first absorbs energy from a pump source (such as a flash lamp or semiconductor laser), exciting the particles to a high energy level. When the energy accumulates to a threshold, it is rapidly released via a trigger signal (electrical pulse, optical signal, etc.), forming a pulsed laser with an ultrashort duration: pulse widths can range from nanoseconds to femtoseconds, with very high temporal resolution. This allows for capturing fast dynamic processes, thus facilitating efficient and rapid height measurement.

[0020] S2: Data processing, including sampling the collected data, taking the first height of the continuously rising sampling point as a1, and the last sampling height of the continuously descending sampling point as an; since the height of the main body of the dam glue tends to be continuous and stable when it increases or decreases, by taking the first height of the continuously rising sampling point as the sampling starting point of the cross section and the end of the continuously descending sampling point as the sampling end point, the interference can be eliminated to the maximum extent, and the outer contour of the cross section can be obtained as realistically as possible, avoiding the deviation of the cross section acquisition due to sampling interference, thereby adversely affecting the accuracy of the final calculation.

[0021] S3: area summation, ,in, is the cross-sectional area between adjacent sampling points, and S is the total area. According to the accuracy requirements of the detection, the sampling points are set as densely as possible; when the sampling points are dense enough, the arc surface of the outer contour between two adjacent sampling points on the cross section of the dam glue can be approximated to a straight line segment, so that the cross section between the two adjacent sampling points can be approximated as a trapezoid, where the height collected in the previous time is the upper base, the height collected in the next time is the lower base, and the distance h between the two sampling points is the height. Then, the size of the cross section of the area can be calculated using the trapezoidal formula. Finally, the cross sections of each area are accumulated to obtain the area of ​​the entire dam glue cross section. In this way, while the cross-sectional area of ​​the dam glue can be obtained as accurately as possible, the difficulty of data collection and the complexity of calculation are reduced, which reduces the amount of data processing required by the processor, improves the detection speed, and reduces the performance requirements for the processor.

[0022] S4: Qualification: Whether the dam glue application meets the design requirements can be determined by comparing the total area S calculated in step S3 with a preset area. If the calculated total area S is greater than the preset area, the product is considered qualified. The system then controls the corresponding equipment to transfer the tested product to the next process, while simultaneously performing other necessary operations such as counting the number of qualified products. If the total area S is less than the preset area, the product is considered unqualified. The system then controls the corresponding equipment to transfer the product to the NG area for further processing. This results in the cross-sectional inspection results of the dam glue. To alert staff to and address unqualified products immediately, step S4 preferably also includes the step of outputting and displaying the results via a human-computer interaction device. This can be done via a display, using a warning color, or flashing. Alternatively, an audible and visual alarm can be added. Displaying and outputting the processing results via the human-computer interaction device facilitates staff access to the inspection results.

[0023] As a further preferred embodiment, step S2 further includes a filtering step, which includes filtering one or more sample heights of sudden rise and fall. Filtering steps. During the detection process, the sampled values ​​on the main body of the dam glue basically tend to be steadily and continuously increasing or steadily and continuously decreasing. However, in the early stage of the detection and near the end of the detection, the glue surface of the normal dam glue is gently rising or gently falling (similar to a semicircular arc structure or a D-shaped structure). However, at the critical position between the dam glue and the wafer surface, the laser will produce obvious fluctuations near this position. For example, near the critical point between the rising side of the glue surface of the dam glue and the wafer, and near the critical point between the falling side of the glue surface of the dam glue and the wafer, the data obtained by laser ranging will produce one or more obvious fluctuations. We can also call this one or more obvious fluctuations noise points. These noise points are not real dams. If the location of the glue is unknown, then if it is collected and calculated, the final calculated cross-sectional area value will be inaccurate, that is, the calculated cross-sectional area will be larger than the actual cross-sectional area of ​​the dam glue. In order to control the cross-sectional area of ​​the dam glue within the preset range, it is necessary to reduce the amount of glue during the application of glue, which will result in the actual cross-sectional area of ​​the dam glue being smaller than the cross-sectional area required by the design, or even the actual amount of glue of the dam glue being smaller than the amount of glue required by the design, thus failing to meet the process requirements of the product. For this reason, it is necessary to remove these obviously fluctuating collection points so that the cross-sectional area obtained by the collection and calculation can be closer to the actual cross-sectional area, thereby obtaining a more accurate amount of glue applied. In the actual processing process, in order to avoid omissions in the detection of the dam glue, the detection coverage width is often greater than the width of the dam glue, such as Figure 1 As shown, in Figure 1 The detection starting point 1 and the detection end point 70 are both beyond the detection position of the cross section for this reason. Figure 1 The data collection curve shown in the figure (the horizontal axis is the number of collection points, the vertical axis is the height), data collection starts from point 1, near the critical point between the rising side of the dam glue surface and the wafer (that is, Figure 1 There are several obvious fluctuations between the 7th and 16th points in the figure. Similarly, there are several obvious fluctuations between the lower side of the dam glue surface and the critical point of the wafer (that is, Figure 1 The 51st to 60th point in the image (in the image) produces multiple obvious fluctuations. First, according to step S2, the first height of the continuously rising sampling points is used as the sampling starting point of the cross section, and the end of the continuously falling sampling points is used as the sampling end point. Although this step can remove some interfering noise points, some interfering noise points may still not be removed, such as Figure 1 Points 11 to 15 in the figure are continuous rises, and points 52 to 55 are continuous falls, but these points are not the glue surface of the dam glue; then these points need to be removed by removing one or more sampling heights of sudden rise and fall. By filtering out these obvious filters, we can obtain data that is closer to the cross-section of the dam glue. In addition, we first collect all the height data at the preset cross-section detection position of the dam glue at one time, then analyze and process this data according to the above steps, and calculate and sum the area of ​​the final separated data to calculate the total area of ​​the cross section.

[0024] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting dam glue, characterized by: The following steps are included S1: Data collection, along the cross-section direction of the dam glue preset by the system, the outer contour of the dam glue is height-measured at every set interval h. Data collection; ; S2: Data processing, including sampling the collected data, taking the first height of the continuously rising sampling point as a1, and the last sampling height of the continuously falling sampling point as an; S3: area summation, ,in, is the cross-sectional area between adjacent collection points, and S is the total area; S4: Qualified judgment: if the total area S is greater than the preset area, it is qualified; if the total area S is less than the preset area, it is unqualified.

2. A dam glue detection method according to claim 1, characterized in that: Step S2 also includes a filtering step, which includes filtering one or more sample heights of sudden rises and dips Filtering steps.

3. A dam glue detection method according to claim 2, characterized in that: In step S1, the laser rangefinder is used to measure the height of each acquisition point. Collect.

4. A dam glue detection method according to claim 3, characterized in that: The laser rangefinder is operated in a pulse triggering manner. In the interval between each pulse triggering, the laser rangefinder moves laterally by a distance h.

5. The dam glue detection method according to claim 1, characterized in that: Step S4 also includes the step of outputting and displaying the judgment result through a human-computer interaction device.

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