I. Introduction

In the modern electronics manufacturing industry, the efficient and precise operation of Surface Mount Technology (SMT) production lines is crucial. Automatic Optical Inspection (AOI) equipment, as a key component in SMT production lines, plays an irreplaceable role in ensuring product quality and improving production efficiency. In-depth research into the mainstream brands of SMT AOI equipment and their relevant characteristics will help electronics manufacturing companies make more informed decisions when selecting equipment, and also provide a reference for equipment manufacturers' technological improvements and market expansion.

II. Mainstream SMT AOI Equipment Brands

(I) Shenzhou Vision: Shenzhou Vision's involvement in the research and development of AOI equipment in China dates back to 2003, when it began developing its own brand of AOI automatic optical inspection equipment.

(II) Zhenhuaxing: As a domestic brand, Zhenhuaxing enjoys high recognition in the Chinese SMT industry. Its equipment is competitive in terms of performance and price, and is therefore used by many small and medium-sized electronics manufacturing enterprises in China.

(III) Mirtec/Meilu: This is a well-known brand with advanced equipment technology, widely used in SMT production lines worldwide. Relevant research shows that its equipment has high detection accuracy for miniature components, performing exceptionally well in detecting the mounting quality and pin soldering of components as small as 0201 or even smaller, meeting the strict requirements of some high-end electronic products for SMT mounting quality.

(IV) TRI (Test Research, Inc.): In the field of SMT testing equipment, TRI is one of the important manufacturers. Its AOI equipment has a high level of technological maturity, and its detection accuracy is recognized in the industry. According to industry surveys, it has numerous customers worldwide, especially large electronics manufacturing companies, which tend to choose TRI equipment due to their high demands for equipment stability and efficiency.

(V) E-Vision: Since 2006, E-Vision has been professionally engaged in the research and development, production, sales, and after-sales service of AOI optical vision inspection equipment, and is an integrated AOI optical inspection equipment supplier. It provides visual inspection solutions for SMT and DIP customers, and its equipment is sold in Europe, America, and Southeast Asian countries, earning a good reputation. III. Technical Characteristics of SMT AOI Equipment from Various Brands

(I) Shenzhou Vision

Fast Programming Speed:  It uses a statistical modeling method for programming, which is relatively simple and easy to use. This method allows for quick modeling and setting of the detection object, reducing the complexity and time cost of programming, enabling the equipment to be quickly put into production and testing. According to actual production data, it can quickly switch detection programs to adapt to different PCB board testing needs when facing multi-variety, small-batch production tasks. High Cost-Effectiveness: While ensuring detection performance, its equipment price is more advantageous compared to foreign brands. Relevant research indicates that this advantage can save companies equipment procurement costs, which is particularly attractive to small and medium-sized manufacturing enterprises with limited budgets but needing to guarantee a certain level of production quality. Certain Technological Innovation: Through its own technological research and development, it continuously improves equipment performance. According to market feedback, this move has forced foreign brands to lower their prices by more than 30%, demonstrating a pioneering role in the Chinese AOI equipment market.

(II) Zhenhuaxing

Detection Accuracy Range Adapts to Multiple Needs: In terms of component position accuracy and solder joint quality detection, Zhenhuaxing's equipment can meet a range of testing tasks, from general production needs to higher quality requirements. Whether it's large-pitch ordinary components or precise micro-components, it can provide reasonably accurate detection results to a certain extent. Good Ease of Operation: The equipment's operating interface is designed to be user-friendly.  Relevant tests show that operators can easily master the equipment's operation skills after appropriate training, thus reducing the company's personnel training costs and the difficulty of learning to operate the equipment.

(III) Mirtec/Meilu

High-Precision Detection Capability:  With the help of advanced optical imaging systems and precise algorithms, it can detect very small defects in micro-components. For example, it can achieve high-precision detection of the mounting quality and pin soldering of components of 0201 or even smaller sizes. Multifunctional Integration: In addition to conventional SMT mounting detection functions, it often integrates other related detection functions or can be well integrated with other equipment, which helps companies build a more comprehensive and efficient SMT production line testing system.

(IV) TRI

High Stability: Its equipment adopts advanced mechanical structure design and a stable electrical control system, making it less prone to failure during long-term continuous operation. In the mass continuous production of large-scale electronic product manufacturing enterprises, maintaining high-precision and high-accuracy inspection work is crucial to ensuring the smooth progress of the production process.

Complex algorithms ensure accuracy:  Using mature algorithms to analyze the collected images, various complex defect types can be accurately identified and distinguished. Whether it's excess solder paste, insufficient solder paste, or displacement in solder paste printing, or various defect types such as missing, misaligned, or displaced components, all can be accurately detected, reducing the occurrence of misjudgments.

(V) Ecotron

Comprehensive visual inspection solution:  Self-developed software provides visual inspection solutions for different SMT and DIP processes. It can handle both assembly and post-soldering inspection in SMT processes, as well as DIP (dual in-line package) related inspections, demonstrating the comprehensiveness of the software and equipment functions. Multiple inspection modes:  The equipment includes various types of AOI (Automated Optical Inspection) devices, such as online AOI, offline AOI, dual-track online AOI, large-size non-standard customized AOI, top and bottom illumination double-sided inspection AOI, and bottom illumination AOI. Different types of equipment can adapt to different production scenarios. For example, online AOI can perform full inspection directly on the production line, improving production efficiency, while offline AOI can be used for sampling inspection or inspection of specific batches of products.

IV. Comparison of Performance Parameters of Different Brands of SMT AOI Equipment

(I) Detection Accuracy

Mirtec/Mirtec generally excels in detecting tiny components, capable of detecting minute defects as small as 0.1-0.2mm. Its optical imaging system boasts ultra-high resolution, providing a technical foundation for identifying ultra-small components and subtle solder joint anomalies. TRI (Test Research, Inc.)  With its high-precision image acquisition sensors and rigorous algorithmic logic, it can achieve high accuracy in detecting rework areas, precisely detecting down to the microscopic level of solder joint size and shape, and identifying extremely subtle differences. Shenzhou Vision: In terms of detecting conventional SMT component placement, it can meet the accuracy requirements for detecting larger defects of approximately 0.3-0.5mm. Although there is still a certain gap compared to well-known international brands in terms of micro-size detection accuracy, its accuracy is sufficient to provide adequate quality control assurance for general conventional electronic manufacturing production. Zhenhua Xing's inspection accuracy can basically meet the requirements of general production quality control. For example, it can achieve good control over the placement accuracy of common components such as diodes and resistors.  It also has a certain competitive advantage over domestic brands in the inspection of miniaturized components (such as 0402 size).

(II) Inspection Speed

TRI (Test Research, Inc.) uses advanced processors and optimized detection algorithms, enabling fast scanning and analysis of images when processing complex circuit board inspection tasks. Its in-line AOI equipment can achieve a line scanning rate of several centimeters per second for conventional size PCBs, significantly improving inspection efficiency on the production line. Mirtec/Mirtec stands out in terms of inspection speed with its efficient optical imaging capture system and real-time data analysis capabilities. For example, when performing AOI inspection in high-speed SMT production lines, it can quickly complete the element inspection of the entire PCB board in a short time, ensuring the production line rhythm. Shenzhou Vision's inspection speed is average among domestic brands, but its faster programming speed can reduce non-inspection time to a certain extent, indirectly improving overall production efficiency. When performing small to medium-scale SMT PCB board inspection tasks, it can achieve an inspection efficiency that basically meets the normal flow of the production line. Zhenhua Xing's equipment inspection speed is suitable for low-end to some mid-to-high-end production speed requirements. When inspecting small to medium-sized PCBs with relatively less dense component layouts, it can maintain a stable and appropriate inspection speed, avoiding situations where inspection cannot keep up with the production rhythm.

(III) Detectable Defect Types

Econix can detect numerous common defects in SMT assembly, such as defects in the solder paste printing process (presence/absence, offset, insufficient solder, excessive solder, open circuit, short circuit, contamination, scratches, etc.), post-soldering component defects (missing components, extra components, offset, skew, tombstoning, side mounting, flipped components, wrong components, damage, reverse polarity, XYθ offset data output, etc.), and solder joint defects including excessive solder, insufficient solder, cold solder joints, short circuits, solder balls, excessive glue, unexposed pins, copper foil contamination, etc. Mirtec/Meilu possesses powerful detection capabilities for extremely fine defects such as very small solder shorts and open circuits, tombstoning and side-standing of tiny pin components, and uneven solder paste distribution.  It can also accurately determine the mounting status of components with complex optical characteristics. TRI (Test Research, Inc.) can detect a wide range of complex defects, from macroscopic issues like missing, misaligned, and incorrect components to microscopic defects such as internal voids in solder joints and poor wetting between solder paste and pins. Its detection range covers almost all common and some uncommon hidden problems in the SMT process, from placement to soldering. Zhenhuaxing can detect typical problems commonly found in SMT assembly and soldering processes, such as component tilting, insufficient solder, solder shorts, cold solder joints, reversed components, misplacement, deformation, missing components, and lifting, playing a good role in ensuring basic production quality.

V. User Evaluation of Different Brands of SMT AOI Equipment

(I) Shenzhou Vision

Views of Small and Medium-Sized Manufacturing Enterprises

Positive evaluations generally consider Shenzhou Vision's equipment to be cost-effective. For small and medium-sized electronic manufacturing enterprises, the equipment price meets their budget constraints. Relevant company cases show that with limited company funds, they can introduce AOI equipment at a relatively low cost for basic production quality control. For example, some small-scale electronic processing plants, after using Shenzhou Vision's AOI equipment, can effectively improve their product yield and avoid excessive defective products due to the inaccuracy of manual visual inspection. Negative evaluations: Compared with international major brands, the detection accuracy needs further improvement. Especially when facing the detection needs of ultra-small components and fine circuits in some high-end electronic products, Shenzhou Vision's equipment may not be able to meet the requirements. According to relevant production tests, in the ultra-small chip placement and soldering detection tasks used in smartphones, there may be a higher rate of missed detections or misjudgments.

(II) Zhenhuaxing

Views of Domestic SMT Manufacturers

Positive evaluations: The operation is relatively simple, and the equipment is easy to use. According to company feedback, on-site engineers can operate the equipment and issue detection tasks after a short training period. Moreover, the equipment has good stability and can maintain stable detection accuracy during long-term operation, which is very important for the stable execution of production plans. Many traditional domestic electronics companies have reported that after using Zhenhuaxing's AOI equipment, downtime due to equipment failure is relatively low. Negative feedback: In some complex SMT process scenarios, such as multi-layer PCB boards with many printing layers and special material component placement, the innovative and high-end functions (such as 3D shape detection of extremely small pitch components) are relatively lacking, affecting their application in improving production quality on a broader level.

(III) Mirtec/Meilu

Feedback from international corporate clients

Positive feedback from multinational electronics manufacturing companies generally acknowledges its high-precision detection capabilities and reliability. For example, several internationally renowned large-scale electronics manufacturers use Mirtec/Meilu's AOI equipment in their high-end product lines (such as high-end server circuit board production, aerospace electronic equipment manufacturing, etc.) to ensure a zero defect rate or extremely low defect rate in their manufacturing process, believing that its high precision greatly contributes to improving production quality. Negative feedback: The equipment is expensive, resulting in high procurement and maintenance costs. According to market research, emerging electronics companies in some developing countries often shy away from Mirtec/Meilu products due to budget constraints; moreover, the equipment parts rely on imports, resulting in longer repair cycles in case of failure.

(IV) TRI

Feedback from the electronics manufacturing industry

Positive feedback: The accuracy rate is very high, performing particularly well in complex and precise electronic product manufacturing scenarios. According to actual production data, for example, some high-end smartphone manufacturers use TRI's AOI equipment for smartphone motherboard placement inspection, and it can accurately detect almost all solder paste printing, component placement, and welding defects, greatly ensuring a high yield rate. Furthermore, the equipment is highly stable and can adapt to the high-intensity demands of 24/7 continuous production. Negative feedback: Due to the complexity and high-end nature of its technology, the equipment is relatively expensive, making it too costly for many small and medium-sized enterprises. In addition, the training requirements are high; operators need a considerable amount of time to become familiar with the equipment's operation procedures, ion expansion operations, algorithm adjustments, and other advanced operations, and require highly qualified engineering technicians for maintenance. (V) E-Vision

Evaluation from a User Experience Perspective

Positive Evaluation: E-Vision provides users with comprehensive visual inspection solutions.  Whether in SMT assembly or DIP production processes, from component placement at the source to later welding quality inspection, applicable equipment and corresponding specific solutions can be found.  Its strong flexibility helps enterprises optimize quality control in the entire electronic manufacturing process. In addition, the availability of multiple inspection modes allows enterprises to choose based on actual circumstances or flexibly arrange inspection processes in different production scenarios. Negative Evaluation: In some high-speed, high-precision assembly line scenarios, there is a certain gap in inspection speed and accuracy compared to top international brands. According to on-site production tests, for example, in ultra-high-speed production lines, when inspecting new miniaturized, ultra-high-density circuit boards, the speed may not keep up with production, or the accuracy may not meet the quality control limits.

VI. Market Share of Different Brands of SMT AOI Equipment

(I) Global Market Share

Globally, international brands such as KohYoung Technology, Viscom, and Mirtec have a high market share. According to a report by QYResearch, the top five manufacturers in the global AOI equipment market accounted for approximately 60% of the market share in 2023, with well-known international brands like Mirtec among them. This high market share stems from their advanced technology and long-term accumulation of brand recognition among global electronic manufacturing companies. For example, large electronic manufacturing companies in developed regions such as Europe, the United States, Japan, and South Korea have trust in and a preference for these international brands. Brands like TRI (Test Research, Inc.) also have a certain market share in global SMT manufacturing companies, especially in the high-end electronic product manufacturing industry (such as high-end communication equipment manufacturing and certain aspects of semiconductor manufacturing) where equipment stability and inspection accuracy requirements are extremely high.