Preface

 

 

 

In SMT production line construction, the choice of placement machine is the key to the selection of the entire line body, not only because it is the key equipment that affects production capacity in the entire production line, but also the most expensive equipment. Therefore, for the entire SMT production line, the choice of the production line is mainly the choice of the placement machine.

 

 

 

When choosing a placement machine, there are many brands on the market, and each brand has many varieties. If a production line is randomly configured and several devices are selected from multiple suppliers, the optimal production optimization rate will be very low. How to effectively select equipment among the numerous equipment in the fiercely competitive supply market so that it not only meets the production needs of the enterprise, but also has a certain degree of foresight and obtains good cost performance is an arduous and complex task. Equipment purchase manufacturers do not know how to start at the beginning, and often have various problems when selecting equipment, such as paying too much attention to equipment hardware, starting to consider the purchase from the perspective of equipment, ignoring that it is just a tool; lack of consideration and consideration of the overall production model of the product. Considering the management model; believing that good brand equipment can produce good products, over-investing in the quantity and quality of equipment; or being greatly influenced by brands and peers; poor equipment application efficiency, etc. How to choose a placement machine effectively, quickly and correctly involves many factors. This chapter specifically explains the various factors that need to be considered and inspected when selecting a placement machine, and also introduces the construction, layout and optimization of the production line in detail.

 

 

 

The specific contents mainly include: when purchasing equipment, first analyze your own situation and clarify your own needs; secondly, conduct market research, find out the market situation, collect relevant information and data, and process the collected data; on this basis, Conduct equipment evaluation, selection and procurement, as well as placement machine equipment acceptance.

 

 

 

introduction

 

 

 

When purchasing SMT equipment, you must first determine the attributes of the enterprise. The SMT equipment you choose should be used for EMS companies or to produce your own products to meet needs; whether it should be used for military products or civilian use, etc. There are differences in selection between EMS and those that meet your own production needs, mainly due to the different nature of the products. Generally, EMS companies may produce multiple varieties and small batches, or they may produce large-scale products. In multi-variety production, it faces all products and components, and the selection of feeders and the wear resistance of the machine will be considered. For example, the requirements of high-speed machines and multi-function machines, as well as the flexibility of equipment, put forward different requirements. The equipment that meets their own product needs is often highly reliable or produces very large products in large quantities. For the production of high-reliability products, the placement machine is not the most important, but the furnace selection is. Another reason for producing by yourself is that you can effectively control the cycle, quality and product reliability.

 

 

 

The scale of production is also an important factor that affects the selection of equipment, whether it is used for large-scale production or for small and medium-scale production, whether it is used for scientific research or teaching, etc.; the technical difficulty and development of existing products will also affect the selection of equipment. According to the structure of the product, the use The connection method or the independent method, and the compatibility of the entire line. At the same time, consider the affordability of funds and the technical status of personnel.

 

 

 

Therefore, any SMT production line has certain pertinence. For example, placement machines not only differ in speed and price, but also have many other factors. When these factors are combined, they will have certain characteristics and are suitable for certain products. Production should not be decided without a sufficient understanding of what you are going to do. Only by fully analyzing your own situation and understanding what kind of equipment you need can you make a decision to purchase equipment. That is, thoroughly analyze your own situation and clarify your purchasing needs.

 

 

 

1. Consideration of production scale

 

 

 

The scale of production often determines the type and quantity of equipment, and different scales have different considerations for the production line.

 

 

 

1. Mass production

 

 

 

The enterprise has a large number of orders, and the pursuit of production is efficiency and quality. The enterprise itself needs to put forward more requirements for the production capacity, efficiency and stability of the placement machine. First, determine the range of the production line's output capacity based on the product batch size, and then configure high-speed machines and multi-function machines. The first choice is to use an ultra-high-speed placement machine in conjunction with a multi-function, or multiple high-speed machines in conjunction with a multi-function, as shown in the figure below. This configuration is relatively cheaper and has the characteristics of flexibility. No matter how configured, the calculation of production capacity must be achieved. At this time, vibrating feeders are generally not considered because all components are produced using tape, such as mobile phone production.

 

 

 

 

 

Since processing output of OEM companies is affected by market capabilities, production plans are often unbalanced and highly volatile. When designing lines for large-scale production, output needs and changes must also be considered. Such changes must be expected to a certain extent and have a rough range, such as the stability of monthly orders and product change trends. In addition to considering production capacity and efficiency, line design must also consider its flexibility to adapt to product changes.

 

 

 

2. Small- and medium-scale production For enterprises with medium- and small-scale production, due to the large variety of products and often tight cycles, the company's own survival needs put forward requirements for the speed of changeover of placement machine models and operational flexibility. Generally, enterprises It has 2 to 3 production lines. This production line configuration is shown in Figure 1 and Figure 2 below.

 

 

 

 

 

 

 

 

 

3. R&D and teaching

 

 

 

For scientific research units and schools, relatively speaking, the production is quite small, and the main purpose is small batch trial production and teaching purposes. What the company itself needs is to put forward appropriate requirements for the accuracy and operational flexibility of the placement machine, but there is no requirement for speed. . Generally, a multi-functional production line is enough.

 

 

 

2. Product features and corporate positioning

 

 

 

Buyers must understand the development trends of existing products, products to be produced, and new products, and have an understanding of the product's functions, characteristics, quality requirements, technical difficulty, and development. These are factors that need to be considered when selecting equipment. By understanding the purpose of the product, the size of the printed board, the characteristics of the components on the board such as packaging type and quantity, and the production batch, etc., you can roughly know the selected production line type and equipment range, what are the key equipment and key parameters.

 

 

 

The maximum size of the printed board used in the product determines the processing capacity of the equipment on the production line. Generally, equipment is divided into M, L, and XL types. For different types of products, equipment with different processing ranges can be selected accordingly to avoid waste.

 

 

 

The type of components used in the product, component size, component shape, and density of mounted components determine the placement accuracy of the placement machine, the number of feeders configured, and the selection of camera accuracy. At the same time, buyers must also foresee whether components currently not in the company's products will be used in the next 3-5 years. That is, the development trend of components determines that the selected placement machine must be able to mount the components that will be used. Only with a certain degree of foresight can we consider placement in 3-5 years when selecting equipment. For example, the placement of small components involves the configuration of feeders and nozzles; the placement of POP equipment involves Choice of model and brand.

 

 

 

1. Highly reliable products

 

 

 

In the production of high-reliability products such as military, aerospace, and medical products, the sizes of printed boards usually vary greatly, and the thickness of the boards also varies greatly. There are many types of component packaging forms on the board, and various packaging types will be encountered. In particular, new packaging will be constantly updated according to product needs and design selection. The production of such products is usually limited. Therefore, the equipment is required to have strong ability and flexibility to handle different boards. When choosing a placement machine, the main consideration is the convenience of programming. The placement of components must be extensive and forward-looking. The selection range of feeder types and quantities must be wide. In addition to the tape feeder, the tray feeder The feeder must have strong processing capacity, and a tubular feeder is essential. In addition, the camera must have strong IC processing capabilities. It is required that the camera must be able to identify components larger than 30×30 and with a spacing of less than 0.5mm; the processing range of printed board size should be as large as possible; if the forward-looking nature of the equipment is considered, it is best to be able to When placing POP components, placement accuracy and precise control of patch pressure must be considered, while placement speed is secondary.

 

 

 

In addition, to ensure product quality and product life, the reliability of solder joints is key. Therefore, for the selection of the entire line, the welding furnace is the most important equipment. Under limited resource conditions, the best furnace must be selected. This type of equipment currently has a series of products from multiple manufacturers on the market, and can be selected according to the company's products and output.

 

 

 

2. Digital mobile products

 

 

 

For large EMS processing enterprises, such as mobile phone product manufacturing, the board sizes of their products are not large, and the sizes are similar, and there are no thick boards. There are many types of resistive and capacitive components on the board, but there are fewer types of tray components used in ICs compared to communication products. The component packages are smaller, and the package spacing tends to be miniaturized. New packages will continue to be used, and the production output is large. .

 

 

 

This type of production line must produce at high speed and efficiently. It is critical to choose a high-speed placement machine. In addition to high placement speed, the issue of component miniaturization must also be considered to ensure the placement of 0201 small components, and at the same time, consider the miniaturization of packaged components. The development trend is that machines that can mount 01005 components are better. The multi-function machine requires a certain degree of accuracy to ensure the placement accuracy of small components, thereby ensuring production quality. For example, it can place components such as CSP with a pitch of 0.3mm. At the same time, we must also consider the trend of packaging developing in the 3D direction, and have a certain degree of forward awareness. It is best if we can mount POP, which is critical to the pressure and control of the Z-axis. It is also not necessary to choose a tube feeder for the range of feeders.

 

 

 

It is not necessary to choose the largest size machine for the width of the board, generally 250mm is enough. Due to the small size of the board, in order to save space and furnace efficiency, dual-track equipment can be used to produce products with small and large batches of mobile phone boards. The front and back sides are processed on the same production line at the same time, and each placement machine is mounted at the same time. On the front and back sides of the board, components are mounted on one track on the front and on the other track on the back. The efficiency of the furnace is doubled. For specific production line layout, please refer to the production line layout introduction later in this chapter. In addition, when multiple machines are connected, the stability of the equipment is very important. If one machine shuts down, other machines will shut down, affecting production. Therefore, the placement machine should have high equipment stability, and the lower the failure rate, the better.

 

 

 

In order to improve the production efficiency of the entire line, each piece of equipment must have optimization software, and after being connected, the balance of the entire line can be optimized. When optimizing the entire line, the high-speed machine must be the bottleneck.

 

 

 

In order to save the time of changing lines, it is best to predict the usage of materials in advance if the equipment can change materials continuously. There are currently many products of this type of equipment on the market, such as the Global GC series.

 

 

 

3. Small and medium-sized EMS processing industry enterprises

 

 

 

Small and medium-sized EMS processing industry enterprises face various users, including military/medical products and MP3 and other civilian products. Since customers cannot choose, they have to process whatever boards they receive. The sizes of printed boards for such products usually vary greatly, and the thickness of the boards will also vary greatly. The manufacturability design of product boards varies widely, and for welding Quality makes a difference. There are many types of component packaging, and various packaging types will be encountered, and the output of the product is not necessarily certain. Sometimes the batch size is small, sometimes there is a certain batch size or even a large batch size.

 

 

 

This type of product requires in addition to the equipment's strong ability to handle different boards, strong flexibility, convenient programming of the placement machine, flexibility in line changes, the largest possible printed board size processing range, and the breadth and foresight of mounted components. , there will also be requirements on the speed of the equipment. The speed requirements of the placement machine will be much higher than those of the military industry, and it can even be used for mass production. Therefore, the choice of placement machine is between medium speed and high speed, and even a high-speed machine can be selected if conditions permit. Since flexibility is the main trend in future development, there are currently more and more manufacturers of this type of equipment.

 

 

 

In addition, due to different customers, in order to ensure product quality, the entire line configuration must be consistent, and a printing press and reflow oven that matches the line body must be selected.

 

 

 

3. Production process

 

 

 

The characteristic of SMT production is that it is process-centered. When purchasing equipment, buyers must be clear about the process flow used in future production lines. It will also determine the model and configuration of the selected equipment as well as wiring. For example, production line wiring, different companies and different products require the use of different SMT production lines, with either connection methods or stand-alone operation methods. The reason why both exist is because each has its own pros and cons. Different production products, different production processes, and equipment selection will also be different.

 

 

 

1. Connection method

 

 

 

The connection method, also called a fully automatic production line, is the current mainstream method. Almost 99% of SMT manufacturers use the connection method, which is a fully automatic production line from solder paste printing machine, component patching, welding to AOI (as shown in the figure below). The advantages of this approach are:

 

 

 

 

 

① The production efficiency is high, the production process time is short, and the time is controllable. Through computer online management, offline programming, and program optimization, the potential of each device can be fully utilized. The optimization of the program effectively solves the time matching problem and bottleneck problem between equipment in production, and is suitable for large-volume and large-scale modern production requirements.

 

② Wiring can reduce the causes of production quality problems caused by boards and components. Because the PCB and components stay for a short time from unpacking to soldering, the effects of environmental hazards such as oxidation and moisture absorption are avoided.

 

③ Able to ensure high-quality products produced in large quantities. Only by connecting screen printing machines, patch machines and reflow ovens to online production can real-time computer online quality tracking be achieved. When defective quality occurs, timely feedback can be achieved, and equipment adjustments and maintenance can be carried out in a timely manner to avoid large batches of defects. Appear.

 

④ The solder paste will not be exposed to the air for a long time, which is very beneficial for lead-free production.

 

⑤ In terms of production management, it is conducive to the formulation of production plans. Through computer online network management, material supply, production and sales links can be reasonably arranged.

 

 

 

The main disadvantage of in-line production is that the price of the entire line is high. If the line design is not comprehensive, the utilization rate of the printing press and reflow oven cannot reach 100%, resulting in a waste of limited resources.

 

 

 

2. Stand-alone operation mode

 

 

 

When designing a production line, it is often configured according to the production of a specific product. When this product is produced, due to the optimal configuration, the entire production line is optimized and intact, and there is no waiting or connection between the printing machine, placement machine and reflow oven. It's perfect, each device is maximized, efficiency is maximized, and the advantages of connection are revealed. But the production line often cannot be a single variety and is constantly changing. At this time, every situation will occur, such as the placement machine becoming a bottleneck, or the printing machine becoming a bottleneck, or the reflow oven becoming a bottleneck. No matter the previous situation, it will cause a waste of energy resources. The idle reflow oven causes a waste of energy, and the idle high-speed machine causes a waste of costs. Therefore, stand-alone independent operation is sometimes used. The advantage of this method is that equipment occupies less money and saves costs and energy, but management is more difficult and planning and arrangements must be more precise.

 

 

 

For example, a manufacturer that produces high-frequency heads has a large batch volume, simple product manufacturing, many small resistance and capacitance components, and small board size, and most of them are assembled boards. This kind of product takes a long time to mount, and the printing and welding time is relatively short. If in-line production is used, a large number of production lines will be needed, and the equipment capital will be relatively large. The bottleneck is placement speed. The workload of printing and welding is relatively small, so choose non-connected production, such as 6 screen printing machines, 19 high-speed machines,The configuration of 14 multi-function machines and 2 reflow soldering furnaces improves equipment utilization, saves energy and equipment costs, and ensures the completion of production tasks. The annual output of high-frequency head production has reached 21 million units, and the overall production efficiency and effectiveness have reached a high level.

 

 

 

The disadvantage of single-machine operation is that it requires very careful planning and scheduling, which puts forward higher requirements for factory management, especially for the constantly changing multi-variety and small-batch products.

 

 

 

3. Influence of process flow

 

 

 

There are the following six types of assembly processes. Each process has different requirements for equipment. See the table for details.

 

 

 

 

 

What is specifically mentioned in the above table is the production of side A THC and side B SMD in single-sided mixing. The process flow of the board is different, and the selection and configuration of the equipment are completely different. In method 2, in addition to adding a dispensing machine , an automatic plug-in machine is also required.

 

 

 

4. Existing human resources of the enterprise

 

 

 

If the company already has patch equipment and needs to purchase new equipment, it needs to consider the utilization of the company's existing equipment and human resources, and coordinate and match the purchased equipment with the existing equipment and adapt to the existing personnel.

 

 

 

If the existing equipment engineers are familiar with a certain type of equipment, when purchasing new equipment, they should give priority to purchasing equipment of the same brand. This way the equipment engineers can become familiar with the equipment quickly and put it into use as soon as possible. If another model is changed, the engineers need to be familiar with it again. This model. At the same time, equipment of the same brand has good interchangeability and is easy to repair and maintain. Therefore, when purchasing equipment at the initial stage, we put forward requirements. We must pay attention to the needs of future production development and the compatibility when adding and purchasing new equipment. We must not have multiple wire bodies, otherwise the spare parts, maintenance and repair of the wire bodies will require multiple personnel. The incompatibility of the feeder will increase the purchase cost. If a certain equipment does not even have service personnel, it will be more troublesome and cause losses to the enterprise. Enterprises often do not pay attention to this waste of resources.

 

 

 

5. Cost analysis

 

 

 

Cost analysis considers two issues: first, the company's own financial capabilities and how much money the company is prepared to invest in equipment; second, how the company considers the return on investment, equipment depreciation time, capital recovery time, and profit margins.

 

 

 

Funding conditions often play a crucial role in the selection of equipment. Once the amount of funds invested in the company's budget is determined, the grade range of the equipment is basically determined. At the same time, the development prospects of the enterprise must also be considered. If the prospects are good, the initial investment will be larger. If the prospects are unclear, investment should be cautious.

 

 

 

The company's cost structure is shown in the figure below. Production costs include fixed costs, variable costs, material costs and engineering costs. Fixed costs are divided into equipment depreciation and equipment maintenance, while variable costs include maintenance costs and equipment operating costs. In the SMT industry, equipment capital investment accounts for a large proportion of the entire capital investment, that is, fixed costs are very heavy. How to recover the investment in the shortest time is a question that every investor must consider. Otherwise, if the investment cannot be realized, the maximum profit will be obtained. Purpose. Therefore, even if you have sufficient funds for equipment investment, you should not invest too much blindly. You must calculate the return on investment of the equipment. Generally, the current investment recovery time is about 3 years, and it takes 4-5 years in the early stage. If the investment is too large and the recovery time is too long, the intensity and proportion of the investment should be considered. Originally designed with 5 lines, now only 2 lines can meet the requirements. Not investing all at once, but investing in stages, etc. If money is tight and the cost is best recovered within 1 year, you can purchase low-cost equipment or second-hand machinery.

 

 

 

 

 

In addition, the equipment itself has two categories: necessary and optional configurations. These configurations are to strengthen the equipment's capabilities and enable the equipment to play a greater role, but at the same time it will increase the cost of the enterprise's investment; how to maintain a competitive advantage in the same industry, To maximize the potential of the equipment and obtain a certain profit at the same time, choosing a better balance point is an issue that needs to be considered.

 

 

 

6. Image and brand effect

 

 

 

If the equipment invested by the enterprise requires a certain social image, such as a national key investment project, it needs to pass inspection and receive frequent visits, and the equipment is required to have image and brand display. In addition, the company needs to accept orders from certain important customers, and these orders play a vital role in the company. At this time, the image and brand of the equipment are even more important. Starting with hardware equipment is very helpful in improving the corporate image. Brand is the most important factor when choosing equipment. Therefore, sometimes image will also affect the choice of equipment. Find out whether your company has needs in this regard.

 

 

 

For example, if several manufacturers that specialize in outsourcing receive an order from a well-known brand at the same time, then they will have an advantage in purchasing famous brand placement machines, such as Universal's equipment. Therefore, when purchasing equipment, you must also consider the brand effect, because purchasing general brand equipment will lose orders from famous brands. Another example is a factory that produces computer handwriting input boards. According to the complexity of the product, technically speaking, it is enough to buy a general mid-range line. However, this is a national key project. Considering the influence and future development, it may be better to buy high-end equipment. s Choice.