Preface

 

 

 

Since the birth of the placement machine in the early 1980s, the basic functions have not changed much, but the placement requirements are mainly speed and accuracy requirements. With the rapid development of the electronic information industry and the miniaturization and high density of components, The development of assembly is no longer what it used to be. We exclude from the scope of discussion the so-called small batch-level equipment that was used early and is still used mainly for product trial production and scientific research, that is, manual placement machines, because these placement machines are technically inferior in terms of technical level and scope of use. None of them can be compared with mainstream placement machines. As far as the mainstream placement machines used for mass production are concerned, they can be technically classified into three generations so far.

 

 

 

1. Development stage of placement machine

 

 

 

1. The first generation placement machine

 

 

 

The first-generation placement machine was an early placement equipment that appeared in the 1970s and early 1980s, driven by the application of surface mounting technology in industrial and civilian electronic products. Although the mechanical centering method used by the SMT machine at that time determined the placement speed to be low (1000 to 2000 pieces/hour) and the placement accuracy was not high (X-Y positioning ±0.1mm, placement accuracy ±0.25mm), And the function is simple, but it already has all the elements of a modern chip placement machine. Compared with manual plug-in assembly, such speed and precision are undoubtedly a profound technological revolution.

 

 

 

The first generation of chip placement machines created a new era of large-scale, fully automatic, high-efficiency, and high-quality production of electronic products. In the early days of SMT development, chip components were relatively large (Chip component type was 1608, and the pitch of the IC was 1.27~0.8mm. ) requirements, it can already meet the needs of mass production. With the continuous development of SMT and the miniaturization of components, this generation of placement machines has long been withdrawn from the market and can only be seen in individual small businesses.

 

 

 

2. Second generation placement machine

 

 

 

From the mid-1980s to the mid-to-late 1990s, the SMT industry gradually matured and developed rapidly. Driven by this, the second-generation placement machine adopted an optical system for component centering based on the first-generation placement machine. The speed and accuracy of the placement machine are greatly improved, which meets the needs of the rapid popularization and rapid development of electronic products.

 

 

 

In the process of development, high-speed machines (also known as chip component placement machines or chip shooting machines) that focus on mounting chip components and emphasize placement speed have gradually formed, and multi-function machines (also known as chip component mounting machines or chip shooting machines) that focus on mounting various ICs and special-shaped components have gradually formed. Also known as general-purpose machine or IC placement machine) two models with obviously different functions and uses.

 

 

 

(1) High-speed machine

 

The high-speed machine mainly adopts a rotating multi-head and multi-nozzle placement head structure. According to the angle between the rotation direction and the PCB plane, it can be divided into turret type (the rotation direction is parallel to the PCB plane) and runner type (the rotation direction is perpendicular to the PCB plane or 45° ), please pay attention to the public account for relevant content, which will be discussed in detail in subsequent chapters.

 

 

 

Due to the use of optical positioning and alignment technology, precision mechanical systems (ball screws, linear guides, linear motors and harmonic drives, etc.), precision vacuum systems, various sensors and computer control technology, the placement speed of high-speed machines has reached 0.06 The order of magnitude of s/chip is close to the limit of electromechanical systems.

 

 

 

(2) Multifunctional machine

 

The multi-function placement machine is also called a general-purpose machine. It can mount a variety of IC packaging devices and special-shaped components. It can also mount small chip components. It can cover a variety of components of different sizes and shapes, so It's called a multi-function placement machine. The structure of multi-functional placement machines mostly adopts an arch structure and a translational multi-nozzle placement head, which has the characteristics of high precision and good flexibility. Multi-function machines emphasize functionality and precision, and their mounting speed is not as fast as high-speed placement machines. They are mainly used to mount various packaged ICs and large and special-shaped components. They are also used to mount small chip components in small and medium-scale production and trial production.

 

 

 

With the rapid development of SMT and the further miniaturization of components, and the emergence of more sophisticated SMD packaging forms such as SOP, SOJ, PLCC, QFP, BGA, etc., this generation of placement machines has gradually become unable to meet its requirements and has gradually withdrawn from the mainstream. SMT equipment manufacturers' vision, but a large number of second-generation SMT machines are still in use, and their application and maintenance are still important issues for SMT equipment.

 

 

 

3. The third generation placement machine

 

 

 

In the late 1990s, driven by the rapid development of the SMT industry and the diversified demand and variety of electronic products, the third generation of chip placement machines developed. On the one hand, the new miniaturized packaging of various ICs and 0402 chip components have put forward higher requirements for patch technology; on the other hand, the complexity and installation density of electronic products have further increased, especially the trend of multiple varieties and small batches. Promote placement equipment to adapt to assembly technology packaging needs. The picture below is an example of a third-generation placement machine.

 

 

 

 

 

(1) Main technologies of the third generation placement machine

 

• Modular composite architecture platform;

• High-precision vision system and flight alignment;

• Dual-track structure, can work synchronously or asynchronously to improve machine efficiency;

• Multiple arches, multiple placement heads and multiple suction nozzles structures;

• Intelligent feeding and testing;

• High-speed, high-precision linear motor drive;

• High-speed, flexible and intelligent placement head;

• Precise control of Z-axis movement and placement force.

 

 

(2) Main features of the third generation placement machine - high performance and flexibility

 

• Integrate high-speed machine and multi-function machine into one: Through the flexible structure of modular/modular/cell machine, the functions of high-speed machine and general-purpose machine can be realized on one machine by simply selecting different structural units. For example, it can achieve a mounting range from 0402 chip components to 50mm×50mm, 0.5mm pitch integrated circuits and a mounting speed of 150,000 cph.

• Taking into account both placement speed and accuracy: the new generation of placement machines adopts high-performance placement heads, precision visual alignment, and high-performance computer software and hardware systems, for example, achieving a speed of 45,000 cph and 50 μm under 4 Sigma on one machine or higher placement accuracy.

• High-efficiency placement: Through technologies such as high-performance placement heads and intelligent feeders, the actual placement efficiency of the placement machine reaches more than 80% of the ideal value.

• High-quality placement: Accurately measure and control the placement force through the Z-direction dimension to ensure good contact between components and solder paste, or apply APC to control the placement position to ensure the best soldering effect.

• The production capacity per unit area is 1 to 2 times higher than that of the second generation machine.

• Enables stack-on-pack (PoP) assembly • Intelligent software systems, such as high-efficiency programming and traceability systems.

 

 

2. Development Trend of SMT Machines

 

 

 

The development trend of future chip placement machines can be summarized as "three highs and four modernizations", namely high performance, high efficiency, high integration, flexibility, intelligence, greenness and diversification.

 

 

 

1. High performance

 

 

 

In the development of placement machines, speed, accuracy and placement functions have always been in a contradictory state, forcing people to compromise between speed and accuracy. Therefore, high-speed machines and multi-function machines are the two types of placement machines that are still in operation today. model. However, in the future, the update speed of electronic products will become faster and faster, and the trend of multi-variety and small-batch manufacturing will become more and more mainstream. New packages such as BGA, FC, CSP and PoP will have higher and higher requirements for placement machines. As the market becomes higher and higher, the placement machine model must keep pace with the times. With the development of modularization, modularization, dual-channel conveyance, multi-cantilever, multi-placement head structures, as well as flying centering, lightning placement and other placement machine technologies, in a placement machine, both speed and accuracy are taken into account And the placement function has become a new direction. New high-performance placement machines integrating high speed, high precision, multi-function and intelligence will become the mainstream. The figure below is a schematic structural diagram of the new generation of multi-cantilever and multi-placement heads.

 

 

 

 

 

2. High efficiency

 

 

 

High efficiency means improving production efficiency, reducing working hours and increasing production capacity. Being good, fast and cost-effective is the eternal pursuit of the manufacturing industry, especially today when competition is becoming increasingly fierce. The main way to improve efficiency is automation, which is a technology or means that reduces human labor and strengthens, extends and replaces human-related labor. From automatic control, automatic adjustment, automatic compensation, automatic identification, etc. to higher automation levels such as self-learning, self-organization, self-maintenance, and self-repair. Automation is always achieved with machinery or tools. Informatization, computerization and networking have not only greatly liberated people's physical work, but more importantly, they have effectively improved the level of automation of mental work and liberated part of people's mental work.

 

 

 

For automated CNC equipment such as placement machines, software programming efficiency is crucial to improving equipment efficiency. Developing more powerful software function systems, including various forms of PCB files, directly optimizing and generating patch program files, reducing manual programming time, developing machine fault diagnosis systems and mass production integrated management systems, and realizing intelligent operations will be a high priority in the future. An important link in the development of efficient placement machines.

 

 

 

In addition, improvements in equipment structure and working modes are also important ways to improve production efficiency. For example, when the placement machine does not have much room to explore the potential of placement speed, the structure is an effective method to improve efficiency. The dual-channel conveyor placement machine retains the performance of the traditional single-channel placement machine, and designs the transportation, positioning, detection and placement of PCB into a dual-channel structure. This dual-channel structure can work in synchronous or asynchronous mode, both of which can shorten the ineffective working time of the placement machine and improve the production efficiency of the machine. Another example is the multi-cantilever and multi-mount head structure of the placement machine, which are both effective methods. The figure below is a schematic diagram of a two-way conveying structure.

 

 

 

 

 

3. High integration

 

 

 

High integration refers to the integration of equipment technology and the integration of technology and management; its essence is the integration of knowledge. The integration of equipment technology requires the crossover, grafting and integration of multiple technologies. For example, machine-optical integration; comprehensive application of detection sensing technology, information processing technology, automatic control technology, servo transmission technology, precision machinery technology and overall system technology; coordination and integration of software and hardware technology, etc. The integration of technology and management means making full use of computer, automation and network technologies to realize the organic integration of equipment application and management technology. The utilization of complete sets of equipment, that is, automated production lines, is particularly important. For example, embedding SPC (Statistical Process Control, statistical process control) and traceability systems in SMT production line equipment can give full play to equipment efficiency and improve production capacity and quality.

 

 

 

4. Flexibility

 

 

 

The biggest challenges in future electronic product manufacturing are multiple varieties, small batches and short cycles. The only effective way to adapt to this basic trend is to flexibly mount equipment.

 

 

 

An important mode of flexibility for placement machines is the modularization and modularization of equipment. Modularization is also called building block type. For example, the host of the placement machine is made into a standard equipment and equipped with a unified standard base platform and a common user interface, while the various functions of the dispensing and patching machine are made into functional module components. , the user can install the required functional module components on the host machine or replace new components as needed to achieve the new functional requirements required by the user. Modularization can be understood as the mother-submachine model. For example, the placement machine is divided into a control host and a functional module machine. According to the different needs of the user, the control host and the functional module machine are flexibly combined to meet the user's needs. The module machine has different functions. According to the mounting requirements of different components, it can be mounted with different accuracy and speed to achieve higher efficiency. When users have new requirements, new function module machines can be added as needed; when orders increase, the number of module machines can be increased to increase production capacity without adding new complete machines.

 

 

 

Another mode of flexibility for placement machines is that one machine can be used for multiple purposes. For example, using a "dispensing head" and a "printing head" to replace the placement head to realize the functions of a dispensing machine and a printing press, this performance is particularly useful for scientific research and product development institutions. Of course, this model must consider the compatibility of the model and the adaptability of the interface in all aspects of mechanical structure, electrical control, computer software and hardware, etc. when designing the machine.

 

 

 

Further introduction to flexibility will be introduced in detail later, please follow the official account to pay attention to new content.

 

 

 

5. Intelligent

 

 

 

The intelligence of manufacturing equipment is the most promising direction for the development of manufacturing technology. In the past 20 years, manufacturing systems have been transforming from energy-driven to information-driven. This requires manufacturing systems to be not only flexible, but also intelligent in order to cope with the processing of large amounts of complex information, rapidly changing market demands and fierce competition. Competitive and complex environment. The basis of intelligent placement machines is computer intelligence technology. Smart placement machines have the following features:

 

• Human-machine integration;

• Self-discipline;

• Self-organization and ultra-flexibility;

• Learning ability and self-maintenance ability.

In the future, intelligent placement machines will have more advanced human-like thinking capabilities. With the help of computer-simulated intelligent activities of human experts, they can analyze, judge, reason, conceive and make decisions on the placement process, replacing or extending the human part of the manufacturing environment. Mental work. At the same time, collect, store, process, improve, share, inherit and develop the intelligence of human experts, etc.

 

 

 

The application of intelligence in placement equipment has just begun. The placement function and the detection and analysis function are organically integrated to improve the level of intelligence. For example, a placement machine equipped with an intelligent system can analyze faults based on detected abnormal phenomena (faults). root causes and automatically correct or give improvement suggestions.

 

 

 

6. Greening

 

 

 

Greening is an inevitable trend in the future development of electronic manufacturing. The development of human society will inevitably lead to harmony between man and nature, and chip placement machines are certainly no exception.

 

 

 

Future placement equipment must start from conception, and must fully consider the impact on the environment, improve material utilization, and reduce energy consumption in the design stage, manufacturing stage, sales stage, use and maintenance stage, until the recycling stage and remanufacturing stage. , to maximize user investment benefits.

 

 

 

In recent years, the concepts of greening and environmental protection have taken on new connotations. The so-called environmental protection is in a broad sense. It not only protects the natural environment, but also protects the social environment and production environment, and also protects the physical and mental health of producers. Under this premise, we can manufacture placement equipment with high precision, high efficiency, high quality, short delivery period and good after-sales service.

 

 

 

7. Diversification

 

 

 

Today's world is a diverse and diverse world. The development of different countries and regions is uneven, and the development of different regions in the same country is also uneven. Therefore, there are diversified demands for the level and grade of electronic products. At the same time, different application fields have widely varying requirements for the reliability of the application environment of electronic products, which also makes the product manufacturing process and equipment to create diversified needs.

 

 

 

This diversified demand for the future development of placement equipment will be the intersection of diversified structures and technologies:

 

• Multifunctional and flexible general-purpose placement machines suitable for a variety of products coexist with high-efficiency dedicated placement machines for specific fields and specific products.

• Fully automatic, intelligent, high-precision, high-capacity high-end placement machines that serve large enterprises and high-density assembly, and mid- to low-end ones that meet the needs of small and medium-sized enterprises and general electronic products have their own room for survival and development.

• High-performance mainstream placement machines for large-scale manufacturing in the industrial world are developed together with small non-mainstream placement machines suitable for scientific research, teaching and laboratories.

• As electronic products continue to be miniaturized, 3D assembly and SiP and PoP are used in more products, "board-level" assembly has penetrated upward into the semiconductor packaging field, requiring the accuracy of the placement machine to adapt to the chip.The requirements for chips to be assembled directly on PCB; in addition, the objects dealt with in the field of semiconductor packaging are not only chips. In some package modules, passive components or other micro components need to be embedded, thus extending down to the assembly field. This kind of The intersection and penetration of technology have blurred the boundaries between semiconductor-level placement machines and board-level placement machines. New placement machines that organically integrate the two will be an important development trend.