AOI, X-ray, ICT, FCT

AOI stands for Automated Optical Inspection. It uses optical cameras to capture PCB images, compares them with standard images, and automatically detects defects such as missing components, wrong components, reverse polarity, offset, bridging, etc. during the component placement process, ensuring product quality and improving production yield.

AOI uses the principle of optical imaging. It illuminates the PCB with a light source, the camera captures the image, and then the image processing algorithm extracts the component features. These features are compared with the pre - set qualified standard image data to determine whether there are placement defects in the components.

Factors such as detection accuracy (should meet the component placement accuracy requirements, for example, the accuracy should reach ±0.02mm when detecting 0201 components), detection speed (matched with the production line cycle), software functions (with rich detection algorithms, easy programming, and data analysis), and scalability (supporting the detection of PCBs of different sizes and being compatible with various component types) need to be considered.

Common light source types include white light sources, red light sources, blue light sources, and ring - shaped light sources. White light sources provide a full spectrum and are suitable for general detection. Red light sources have good detection effects on copper foils and solder joints. Blue light sources have high contrast with green solder masks. Ring - shaped light sources can reduce shadows and are suitable for the detection of complex components and PCBs with height differences.

It is necessary to ensure that the PCB surface is clean without contaminants such as dust and oil stains. Check that the PCB positioning Mark points are clear and complete for the AOI device to accurately identify and position. For double - sided mounted PCBs, clearly distinguish the detection surface to avoid misdetection.

Detection parameters include image acquisition parameters (such as exposure time, gain, contrast), detection algorithm parameters (such as threshold, edge detection sensitivity), and detection area parameters (defining the component areas to be detected and the ignored areas). Usually, according to the PCB design, component types, and production processes, the parameters need to be optimized through debugging and trial detection to achieve the best detection results.

AOI can detect defects such as missing components (components not placed), wrong components (wrong component models), reverse polarity (polarity - sensitive components with reversed polarity), component offset (position exceeding the allowable tolerance), solder bridging (solder connecting adjacent pads), component damage (appearance damage), component tombstoning (one end of the component 翘起), etc.

When AOI detects a defect, it will automatically mark the defect location and type and generate an alarm message. Operators need to isolate the defective PCB according to the alarm prompt, and then further confirm it through manual visual inspection or other detection methods. Then, repair or scrap the PCB according to the defect type.

Regularly calibrate the cameras and light sources of the AOI device to ensure accurate image acquisition. Optimize the detection parameters and adjust the algorithms for different types of components and PCB designs. Update the component library and standard image data in a timely manner to adapt to new products and processes. Provide professional training for operators to improve their parameter - setting and defect - judgment abilities.

Daily maintenance includes cleaning the device surface, lenses, and light sources to prevent dust from affecting image quality. Regularly check the operation status of the device's mechanical components (such as guide rails and lead screws), lubricate and fasten them. Check the electrical connections. Regularly conduct functional tests and calibrations on the device to ensure stable detection performance.

The advantages are fast detection speed, which can be used for online real - time detection; relatively low cost; and the ability to visually detect component appearance and surface defects. The disadvantages are that it cannot detect the defects of hidden solder joints (such as the internal solder joints of BGA and CSP), and has limited detection ability for tiny defects (such as voids smaller than 50μm). X - Ray inspection can detect internal defects, but it is slow and costly.

The main functions of AOI software include image acquisition and processing, inspection program programming (defining the inspection area, setting inspection parameters, selecting inspection algorithms), defect recognition and classification, display and recording of inspection results, data analysis and statistics (generating yield reports, defect distribution charts, etc.), and data interaction with other production line equipment (such as pick - and - place machines and rework stations).

Reasons include unreasonable setting of detection parameters (such as too high or too low thresholds), incorrect image recognition caused by component surface reflection or color differences, interference from stains or foreign objects on the PCB surface, contamination of the AOI device lens or light source, and deviations between the standard images in the component library and the actual components.

Re - adjust the detection parameters and optimize the threshold and sensitivity through trial detection. Clean the PCB surface to remove stains and foreign objects. Clean or replace the contaminated lenses and light sources. Update the standard images in the component library to ensure consistency with the actual components. Use multiple detection algorithms to complement each other and reduce the limitations of a single algorithm.

Modern AOI devices usually have good scalability. The inspection area and parameters can be adjusted through software settings to adapt to PCBs of different sizes. For different types of PCBs (such as rigid boards, flexible boards, rigid - flexible boards), as long as they are within the detection capabilities of the device, effective detection can be achieved by adjusting the corresponding detection processes and parameters.

AOI is generally installed after the pick - and - place machine and before the reflow soldering, so as to detect component placement defects in a timely manner and prevent defective products from entering the reflow soldering process, reducing rework costs. It can also be installed after reflow soldering to detect soldering quality, but if problems are found at this time, the difficulty and cost of rework will increase.

By analyzing the AOI detection data, count the occurrence rates and distribution of various defects to identify the weak links in the production process. For example, if the offset defect of a certain type of component occurs frequently, the placement parameters of the pick - and - place machine can be adjusted. If there are many bridging defects, the solder paste printing process or the reflow soldering temperature profile can be optimized.

X - ray inspection uses X - rays to penetrate the PCB and components. Based on the different absorption degrees of various materials to X - rays, grayscale - different images are formed, thereby detecting internal defects in PCB placement, such as voids, cold soldering, and non - wetting in solder joints of packaged components like BGA and CSP, as well as abnormal internal structures of components and foreign objects, ensuring product quality and reliability.

X - rays have penetrability. When X - rays irradiate the PCB, due to the different absorption capacities of various substances on the PCB (such as copper, solder, plastic packaging, etc.) to X - rays, the intensity of X - rays after passing through the PCB varies. The detector receives these X - rays of different intensities and converts them into electrical signals, which are then processed and converted into grayscale images. The internal structure and defect conditions can be judged by analyzing the images.

Factors such as detection accuracy (should be able to distinguish tiny defects, such as micron - level solder joint voids), magnification (meeting the detection requirements of components of different sizes), detection speed (matched with the production line cycle), image resolution (high resolution helps to clearly observe details), equipment scalability (supporting the detection of PCBs of different sizes and being compatible with various detection modes), and software functions (with functions such as image analysis, defect recognition, and data statistics) need to be considered.

Common types include 2D X - ray inspection devices and 3D X - ray inspection devices (such as CT inspection devices). 2D devices have a relatively simple structure and lower cost, and can detect surface and some internal defects of PCBs. 3D devices can obtain multi - layer images and achieve 3D imaging, which can more accurately detect the internal defects of components with complex structures, but the equipment cost is high and the detection speed is relatively slow.

Generally, no special pre - treatment is required, but it is necessary to ensure that the PCB surface is clean without obvious stains and foreign objects; remove metal shielding covers and other accessories on the PCB that may affect the inspection; for multi - layer PCBs, if certain layers are known to be not required for inspection, they can be set in the inspection software to improve the inspection efficiency.

Detection parameters include the tube voltage and tube current of X - rays (affecting the intensity and penetrability of X - rays), exposure time (affecting image brightness and clarity), magnification (adjusted according to component size and detection requirements), detection angle (for 3D inspection devices, different angles need to be set for scanning), etc. Usually, according to the material, thickness of the PCB, and component types, the parameters need to be optimized through debugging and trial detection to obtain the best inspection images.

X - ray can detect internal defects of solder joints of packaged components such as BGA, CSP, and QFN, such as voids, cold soldering, non - wetting, missing solder balls, and solder ball offset. It can also detect cracks and foreign objects inside components, as well as problems such as interlayer short circuits and open circuits inside the PCB.

When X - ray detects defects, a detailed inspection report will be generated, marking the defect location, type, and severity. Operators need to isolate the defective PCB according to the report. For repairable defects (such as some solder joint problems), they can be repaired through rework equipment. For PCBs with serious defects, they will be scrapped, and the causes of the defects will be analyzed to optimize the production process.

Regularly calibrate the X - ray equipment to ensure the stable performance of the X - ray source and detector; optimize the detection parameters and adjust the parameters for different types of PCBs and components; adopt advanced image analysis algorithms to improve the accuracy of defect recognition; provide professional training for operators to enhance their image analysis and defect - judgment abilities; establish standard inspection processes and specifications to reduce human errors.

Daily maintenance includes cleaning the device surface to prevent dust accumulation from affecting heat dissipation; regularly checking the working status of the X - ray tube and monitoring parameters such as tube voltage and tube current; checking the sensitivity and stability of the detector; lubricating and fastening the mechanical transmission components of the device; regularly conducting performance tests and calibrations on the device to ensure accurate and reliable detection results.

The advantages are the ability to detect hidden internal defects of PCBs and components, and it has unique advantages in the inspection of solder joints of packages such as BGA and CSP; it can provide 3D structural information (3D X - ray inspection). The disadvantages are relatively slow detection speed, high cost; professional operators are required for image analysis and defect judgment; X - rays are radioactive to a certain extent, and protective measures are required. AOI inspection is fast, low - cost, and can visually detect the appearance and surface defects of components, but it cannot detect hidden internal defects.

The main functions of X - ray inspection software include image acquisition and processing (adjusting image brightness, contrast, filtering, etc.), defect recognition and marking (automatically or manually recognizing defects and marking their positions and types), 3D image reconstruction (for 3D X - ray devices), generation of inspection result reports (detailed records of defect information, detection parameters, etc.), data analysis and statistics (counting defect occurrence rates and analyzing production process problems), and data interaction with other production line systems.

Reasons include improper setting of detection parameters (such as inappropriate tube voltage and exposure time resulting in poor image quality), limitations of image analysis algorithms (inability to accurately identify complex defects), lack of operator experience (incorrect judgment of images), special materials and structures of PCBs or components (resulting in abnormal image grayscale), and problems with the accuracy and stability of the equipment itself.

Re - adjust the detection parameters to optimize the image quality; upgrade or improve the image analysis algorithms to enhance the defect recognition ability; strengthen the training of operators to improve their professional level; establish a defect sample library for comparative analysis of complex images; regularly maintain and calibrate the equipment to ensure stable equipment performance.

Modern X - ray devices usually have certain adjustability and compatibility. Through software settings and hardware adjustments (such as changing lenses with different focal lengths and adjusting the size of the inspection platform), they can adapt to the inspection of PCBs of different sizes. For different types of PCBs (such as rigid boards, flexible boards, rigid - flexible boards) and components, as long as they are within the detection capabilities of the device, effective detection can be achieved by adjusting the corresponding detection parameters and modes. However, for PCBs with special structures or extremely thin and thick PCBs, specially configured devices may be required.

It is usually installed after reflow soldering to inspect the PCB after welding and timely detect internal defects such as solder joints. It can also set up a separate X - ray inspection station after key processes (such as after BGA component placement) to conduct special inspections on key components to ensure product quality, but this will increase the complexity and cost of the production line.

By analyzing the X - ray inspection data, count the distribution and occurrence frequencies of various defects to identify the weak links in the production process. For example, if the void rate of BGA solder joints in a certain batch of PCBs is found to be high, the solder paste printing amount, reflow soldering temperature profile, or component placement pressure can be adjusted. If foreign objects inside components occur frequently, the quality of incoming components and the cleanliness of the production environment can be checked, and the process can be improved and control can be strengthened accordingly.

An ICT line, namely In - Circuit Test line, is a device that conducts electrical performance tests on PCBs with mounted and soldered components. It makes contact with the test points on the PCB through probes, detects open circuits, short circuits, and whether component parameters (such as resistance, capacitance, and inductance values) meet the design requirements, as well as the soldering quality of components. It can quickly locate faulty components and defective solder joints, ensuring the quality of PCB products and improving production efficiency and yield.

The principle of ICT testing is based on circuit network analysis. The testing equipment applies excitation signals (such as current and voltage) to the test points on the PCB through probes, and then measures the response signals of the circuit. According to the pre - set test program and standard parameters, the actual measured values are compared with the theoretical values to determine whether there are problems such as open circuits, short circuits, and component parameter deviations in the circuit. For example, for a resistive component, a known voltage is applied, the flowing current is measured, and the resistance value is calculated and compared with the nominal value.

When selecting, factors such as testing accuracy (able to accurately measure component parameters, such as a resistance measurement accuracy of ±1%), testing speed (meeting the requirements of the production line cycle), the number of testable points (suitable for the number of test points on the PCB), software functions (with a graphical programming interface, automatic diagnosis function, data statistical analysis ability), equipment compatibility (supporting the testing of different types of PCBs and different component packages), probe service life, and maintenance costs need to be considered. In addition, attention should also be paid to the technical support and after - sales service capabilities of the equipment supplier.

Common ICT devices include bed - of - nails ICT and flying - probe ICT. The bed - of - nails ICT makes contact with the PCB test points through a fixed bed - of - nails, and can test multiple points at one time, with a fast testing speed, suitable for mass production. However, the cost of making the bed - of - nails is high, and the bed - of - nails needs to be replaced for different PCBs. The flying - probe ICT uses movable probes to test points one by one, without the need to make a bed - of - nails, with high flexibility, suitable for small - batch and multi - variety production, but the testing speed is relatively slow.

It is necessary to ensure that the PCB surface is clean without contaminants such as solder dross, tin beads, and oil stains to avoid affecting the good contact between the probes and the test points. Check whether the test points on the PCB are complete and free of oxidation. If necessary, clean or tin - plate the test points. Remove metal shielding covers and other accessories on the PCB that may interfere with the test. For double - sided mounted PCBs, clearly distinguish the test surface.

Test parameters include the type (voltage, current), magnitude, and frequency of the excitation signal; the measurement range (such as the resistance measurement range of 0.1Ω - 10MΩ); the test time (the test duration for each test point); the threshold setting (such as the allowable deviation range of the resistance value of ±5%), etc. According to the circuit design of the PCB, component specifications, and test requirements, the parameters need to be set reasonably through debugging and trial testing to ensure the accuracy and reliability of the test.

ICT can detect open circuits (the circuit is not connected), short circuits (unexpected conduction between different lines), wrong component installation (such as installing a resistor as a capacitor), incorrect component parameters (the values of resistors, capacitors, and inductors do not match the nominal values), reverse component polarity (polar components such as diodes and electrolytic capacitors are installed in reverse), cold soldering (the solder joints seem to be connected but have poor electrical performance), etc.

When ICT detects defects, it will display the defect location, type, and detailed information on the test software interface. Operators need to remove the defective PCB from the production line according to the prompts and use tools such as multimeters and oscilloscopes to further confirm the problems. For repairable defects (such as cold soldering and wrong component installation), repair them with rework tools. For PCBs with serious non - repairable defects, scrap them, record the defect data, and analyze the causes to improve the production process.

Regularly calibrate the ICT equipment to ensure the accuracy of the excitation signal and the measurement system. Keep the probes clean and in good condition, and replace worn or damaged probes in a timely manner. Optimize the test program and accurately set the test parameters. Provide professional training for operators to improve their fault - judgment and handling abilities. Establish standard test processes and specifications to reduce human operation errors.

Daily maintenance includes cleaning the device surface and probes to prevent dust and solder residue from affecting the test. Regularly check the probe pressure to ensure good contact with the test points. Monitor the electrical performance of the equipment, such as the stability of the excitation signal. For bed - of - nails ICT, check the fixing condition of the bed - of - nails and the conductivity of the pins. Regularly back up test programs and data to prevent loss. Perform regular calibrations and professional maintenance according to the requirements of the equipment manufacturer.

The advantages are the ability to directly detect the electrical performance of the circuit, accurately judge component parameters and soldering quality, and precisely locate the fault points; it has a good detection effect on problems such as open circuits and short circuits. The disadvantages are the need to set test points on the PCB, increasing the PCB design and manufacturing costs; it can only detect the areas accessible by the test points, with detection blind spots; the development of the test program is complex, and reprogramming is required for different PCBs. AOI mainly detects the appearance and surface defects of components, with fast detection speed and low cost. X - ray inspection can detect hidden internal defects of PCBs and components, but it has a slow detection speed and high cost.

The main functions of ICT testing software include test program programming (defining test points, setting test parameters, writing test logic), test execution and control (starting, pausing, stopping the test), defect recognition and alarm (automatically judging the test results, marking defects, and issuing alarms), test result display and recording (presenting test data in the form of charts and reports), data analysis and statistics (counting defect types and occurrence rates, analyzing production process problems), and data interaction with other production line systems (such as the MES system).

Reasons include unreasonable design of test points (such as too small a distance between test points and improper location), resulting in poor probe contact or mutual interference; inaccurate setting of test parameters (such as too narrow or too wide a threshold range); probe wear, oxidation, or contamination, affecting the transmission of test signals; uneven PCB surface, causing uneven probe pressure; logical errors in the test program, resulting in misjudgment of normal circuits; unstable electrical performance of the equipment itself, etc.

Optimize the design of test points to ensure reasonable layout, appropriate spacing, and good surface quality of the test points. Recalibrate and adjust the test parameters, and determine the appropriate threshold range through multiple trial tests. Regularly clean, maintain, and replace the probes. Pre - treat uneven PCBs or use adaptive probes. Carefully check and correct the logical errors in the test program. Regularly maintain and calibrate the equipment to ensure stable equipment performance.

Bed - of - nails ICT devices usually need to customize the bed - of - nails for PCBs of different sizes and types, with poor flexibility, but they are highly efficient in mass - producing the same type of PCBs. Flying - probe ICT devices control the movement of probes through software without the need to replace hardware, and can adapt to the testing of PCBs of different sizes and types. Only the test program and parameters need to be adjusted. However, for extremely large - sized PCBs or PCBs with an extremely large number of test points, the testing efficiency may be limited.

ICT testing is usually installed after the reflow soldering process and before the functional test, so as to timely detect the electrical performance problems generated during the soldering and component placement processes, prevent defective products from entering subsequent processes, and reduce rework costs. It can also, according to the production process requirements, set up a separate ICT testing station after the placement of key components to conduct advance inspections on key circuit parts.

By analyzing the ICT testing data, count the distribution and occurrence frequencies of various defects to identify the weak links in the production process. For example, if the defect rate of a certain type of component parameters is high, the quality of incoming components, placement accuracy, or soldering process can be checked. If open circuit or short circuit problems occur frequently, the PCB design can be optimized (such as adjusting the wiring and adding test points), the soldering parameters can be improved, or anti - static measures during the production process can be strengthened.

An FCT line, namely Functional Circuit Test line, is used to verify the functions of PCBs or assembled products after component placement and soldering. It simulates the actual working environment of the product, inputs excitation signals, and detects whether the output signals and various functions of the product meet the design requirements. It can identify potential logical errors and performance issues, ensuring that the product can be used normally. It is a crucial step in guaranteeing the functional integrity and reliability of the product.

The principle of FCT testing is based on the functional characteristics and design specifications of the product. The testing equipment applies specific excitation conditions, such as power supply and signal input, to the tested PCB or product, and at the same time, collects the output signals of the product. These output signals are compared and analyzed with the pre - set correct output data, waveforms, logical states, etc. If the output results do not match the standards, it is determined that there are functional defects, thereby locating the functional fault points of the product.

When selecting, factors such as the comprehensiveness of testing functions (whether it can meet all functional testing requirements of the product), testing accuracy (accuracy in measuring analog and digital signals), testing speed (matching the production line cycle), compatibility (supporting the testing of products of different models and specifications), software functions (with functions such as test program editing, data recording and analysis, and fault diagnosis prompts), equipment expandability (ability to add test modules according to product upgrades), as well as equipment costs and after - sales service need to be considered.

Common FCT devices include dedicated FCT devices based on fixtures and universal FCT devices based on instruments. Dedicated FCT devices are designed for specific products, with strong testing pertinence and high efficiency, but poor flexibility. The fixtures need to be redesigned when the product is updated. Universal FCT devices use reusable test instruments (such as multimeters, signal generators, oscilloscopes, etc.) and achieve the testing of different products through software programming. They have high flexibility and a wide application range, but the development of test programs is complex, and the initial equipment cost is relatively high.

It is necessary to ensure that the PCB has no external damage, good soldering quality, and no obvious defects such as cold soldering and short circuits. Conduct necessary cleaning on the PCB to remove residual flux, dust, and other impurities on the surface. Check whether the connectors, interfaces, etc. on the PCB are installed correctly and without damage. According to the test requirements, perform necessary configurations on the PCB (such as program burning, jumper setting, etc.).

Test parameters include the type (analog signal, digital signal), amplitude, frequency, and duty cycle of the input signal; test time; judgment criteria for output signals (such as voltage range, logic level, waveform characteristics); the sequence and conditions of test process steps, etc. According to the product functional specification and actual working requirements, combined with the performance of the testing equipment, the parameters need to be set reasonably through debugging and verification to ensure the effectiveness and accuracy of the test.

FCT can detect logical function errors (such as abnormal logic control of chips), abnormal signal transmission (signal attenuation, distortion, interference), interface function failures (USB, network interface, etc. unable to communicate normally), power management problems (unstable voltage output, abnormal over - current protection), software function defects (program operation errors, response timeout), etc. These defects may be caused by incorrect component placement, poor soldering, component damage, or design problems.

When FCT detects defects, the testing equipment will record the defect information and issue an alarm prompt. Operators need to mark the defective products according to the prompts and use professional instruments (such as oscilloscopes and logic analyzers) to further analyze the causes of the failures. For repairable problems (such as program errors and component cold soldering), repair them and retest. For products that cannot be repaired, handle them according to the scrapping process, and feedback the defect data to the production and R & D departments to improve the process and optimize the design.

Regularly calibrate the testing equipment to ensure the accuracy of input and output signals. Optimize the test program and accurately set the test parameters and judgment criteria. Adopt multiple testing methods and means (such as boundary condition testing and limit testing) to comprehensively detect product functions. Provide professional training for operators to improve their fault analysis and judgment abilities. Establish a complete test data recording and analysis mechanism, and discover potential problems through the comparison of historical data.

Daily maintenance includes cleaning the surface of the equipment and test fixtures to prevent dust and impurities from affecting the test. Regularly check the operation status of each module of the equipment (such as the power module and signal generation module) and monitor key performance indicators. Check and calibrate the test fixtures to ensure good contact. Update the test software in a timely manner to fix bugs and add new functions. Perform regular comprehensive calibrations and in - depth maintenance according to the requirements of the equipment manufacturer.

The advantage is that it can detect problems from the actual functional level of the product, which is closer to the user's usage scenario, and can identify logical and performance defects that cannot be detected by other tests. The disadvantages are higher testing costs (equipment and fixture costs), complex test program development, and relatively slow testing speed. AOI mainly detects appearance and surface defects, with fast speed and low cost. X - ray inspection can detect hidden internal defects. ICT focuses on the detection of electrical parameters of circuits and can accurately locate faulty components, but none of the three can directly verify the product functions.

The main functions of FCT testing software include test program writing and editing (defining the test process, setting parameters, writing logical judgment statements), test execution control (starting, pausing, stopping the test), real - time data collection and display (displaying input and output signal waveforms and values), automatic defect recognition and alarm (marking faults and prompting according to the judgment criteria), test result recording and report generation (counting the pass rate, recording defect information), data analysis and traceability (analyzing the trend of test data, tracing the product test history).

Reasons include unreasonable setting of test parameters (too wide or too narrow threshold range), logical errors in the test program (inaccurate judgment conditions), performance fluctuations of the testing equipment itself (unstable signal output), poor contact of the test fixture (resulting in abnormal signal transmission), environmental interference (electromagnetic interference affecting signal collection), and compatibility problems in product design (abnormal performance in the test environment).

Re - review and adjust the test parameters, and optimize the threshold through multiple tests. Carefully check and correct the logic of the test program and conduct sufficient test verification. Regularly maintain and calibrate the testing equipment to ensure stable performance. Check and improve the contact condition of the test fixture, and replace the fixture if necessary. Shield or optimize the test environment to reduce interference. Communicate with the R & D department to confirm the compatibility of the product design in the test environment and solve potential problems.

Dedicated FCT devices based on fixtures are usually designed for specific products and have poor adaptability to PCBs of different sizes and types. The fixtures need to be redesigned. Universal FCT devices based on instruments can adapt to the testing of PCBs of different sizes and types to a certain extent through software programming and replacing the appropriate test interfaces, but for products with special functions or structures, some test modules may still need to be customized.

FCT testing is generally set at the end of the production line, that is, after processes such as ICT testing and appearance inspection are completed, to ensure that the products screened by the previous processes are verified for functions in a state close to actual use, and to prevent unqualified products from flowing to the client. According to the product characteristics, phased FCT testing can also be set after the assembly of key functional modules to detect problems in a timely manner and reduce the waste of subsequent processes.

Through the statistical analysis of FCT testing data, the distribution patterns and high - frequency problem points of product functional defects can be discovered. For example, if a certain type of functional defect occurs frequently, the corresponding production processes (such as component placement, soldering, software burning) can be thoroughly investigated. Analyze the correlation between defects and factors such as raw material batches, production equipment, and operators, and improve process parameters, strengthen quality control, and optimize product design accordingly, thereby improving the overall product quality and production efficiency.