Preface

 

 

 

In addition to the host machine, the placement machine also has many accessories. They form a whole with the host machine to complete the placement task. Different configurations have different efficiency in completing the task, and the maximum advantage of the machine is different. However, purchasing these accessories should be determined based on production needs and financial capabilities.

 

 

 

Generally, accessories are optional and need to be selected separately. The cost of accessories accounts for 1/3 to 1/2 of the total machine cost, and mainly includes feeders and consumables. The selection of accessories is divided into three levels. The first level is the accessories that the enterprise must equip. If these are not replenished in time, it will cause downtime; the second level is the accessories that the enterprise needs to equip. If these accessories are damaged, failure to replenish them in time will cause The reduction in equipment speed affects production efficiency; the third level is for reserve accessories if the buyer has sufficient funds. They can be purchased when purchasing the host to enjoy the host's preferential discounts and reduce the cost of future purchases. These spare parts are damaged. It will not affect production later.

 

 

 

With the use of the placement machine, there will also be some parts that need to be inspected and replaced regularly due to wear and tear, so there will be consumables generated by the operation of the equipment. The more fully prepared the consumables are, the more conducive to production, but the pressure on funds will be Increase.

 

 

 

The selection of the equipment's main accessory feeders, consumables and some more independent components, such as sensors and fixtures, will be described.

 

 

 

1. Selection of feeder

 

 

 

1. Feeder selection principles

 

 

 

(1) Type and quantity of feeders

 

 

 

The type and quantity of feeders should be configured according to the packaging form and type of components, and must be configured appropriately. Since the price of the feeder is relatively high, too little will not be enough, and too much will cause waste. It should be configured according to the products with the largest number of packaging forms and components, and an appropriate margin should be left.

 

 

 

(2) The versatility of the feeder

 

 

 

The versatility of the feeder must be considered on the production line to save the cost of purchasing equipment. It is best to use the same brand of machines across different models. It is best to use the same feeder between the multi-function machine and the high-speed machine. The same 8mm tape, 2mm step and 4mm step can be used in common, and plastic and paper tape can be used in common.

 

 

 

Generally, manufacturers will consider the versatility of feeders on their machines, but sometimes manufacturers will design feeders for a specific machine, which limits the use of the feeder on other machines. Specialized machines not only leave a large number of feeders idle, but also require space to store them, which should be noted when selecting.

 

 

 

(3) Feeding method of feeder

 

 

 

Boom machines can support many different types of feeders, such as belt, tray, bulk and tube, etc. This is in sharp contrast to high-speed installation systems, which can only use bulk or belt feeders. When installing many large ICs, such as QFPs and BGAs, boom machines are the only option. In addition to placement accuracy, the high-speed machine does not support the tray feeder is also an important reason.

 

 

 

(4) Development trends of feeders

 

 

 

Feeders are developing from traditional mechanical to electric. Compared with electric feeders, mechanical feeders are divided into paper tapes and plastic tapes, and the steps are also divided into 2mm, 4mm and 12mm, etc., while the electric type not only has no distinction between paper tapes and plastic tapes, but also electronic feeders. The feeder can be stepped between 2mm and 4mm, which is more flexible and cost-saving.

 

 

 

2. Feeder selection

 

 

 

(1) Belt feeder selection

 

 

 

The 8mm tape feeder is the part with the largest number of choices and the largest cost among the feeders. It is also the most critical part in accessory selection. The general experience in selection is: the number of feeders that do not frequently change lines is 1.5 times the number of the largest product varieties; the demand for feeders that frequently change production varieties is 2.5 times the number of the largest product varieties, and is equipped with 4 feed trucks. For example, for small and medium-sized EMS companies, as the variety of components increases, the minimum number of 8mm tape feeders required is about 120 to 180.

 

 

 

Various tape feeders of 12mm, 16mm, 24mm, 32mm, 44mm and 56mm can be selected according to the specific situation; for example, one option is 10 feeders each for 12mm and 16mm; 5 feeders each for 24mm and 32mm; 44mm and 1 each for 56mm feeder. If the product has special requirements, or if the economy is sufficient, these feeders can also be increased in quantity.

 

 

 

(2) Selection of tray feeder

 

 

 

There are two types of tray feeders. One is the IC tray, which can be placed directly on the machine platform. There are not many types of ICs placed in this way. It occupies a larger area, but the price is cheaper. There is almost no investment, and the only sacrifice is is the location of the material station of the machine. Suitable for production models with relatively small IC varieties. The other is a multi-tray dedicated feeder, which can generally place devices with more than 25 pallets, which is basically sufficient for EMS companies.

 

 

 

(3) Selection of tubular vibrating feeder

 

 

 

In large-scale production, it is not necessary to equip a tubular vibrating feeder, but it must be equipped in multi-variety and small-batch production, especially for small and medium-sized EMS companies, because customers often provide rod-type packaging components. The specific configuration can be based on the actual situation. For example, you can choose to install feeders for 6 to 10 types of tubular materials.

 

 

 

(4) Bulk feeder

 

 

 

Bulk feeders do not need to be equipped in general factories, unless they produce some special, batch products that are only supplied in bulk.

 

 

 

2. Selection of consumables

 

 

 

When purchasing a machine, in addition to purchasing accessories to complete the task with the host machine, you must also purchase a certain number of spare parts. The purpose is to prevent machine parts from being damaged and replace them to ensure continued production. If there are no spare parts, one will affect production, and the other will It will be very expensive to buy it separately, but it will be relatively cheaper to buy it together with the console. Another purpose of purchasing spare parts is to ensure that the equipment is always in the best condition of the patch, and the consumable parts of the equipment must be replaced regularly.

 

 

 

The main consumables of the placement machine are: nozzle, cutter, blade, filter, typical sensor, unit head, adjustment fixture, fixture, lubricating oil and filter, etc.

 

 

 

1. Nozzle and nozzle selection support (PIN)

 

 

 

(1) Nozzle

 

 

 

Abnormal phenomena occur during the production and placement process, such as component recognition errors exceeding the range and component loading rate decreasing. This requires considering whether there is an abnormality in the nozzle. The nozzle needs to be detected and replaced in time.

 

 

 

Because when the suction nozzle is defective, worn, clogged, broken, etc., problems such as the mounted components exceeding the detection height range and identification error range will occur during production. Therefore, during the use of the equipment, the height of the suction nozzle must be detected regularly to detect and replace the suction nozzle in time. The nozzle configuration is based on the type of component packaging. Since the nozzle is a wearing part, more configurations should be made based on the service life of the nozzle, the number of placement heads, and the production batch. When negotiating terms with the supplier, in addition to the standard configuration, you can ask for more configurations for free. In addition, in the standard configuration, you can replace uncommon nozzles with commonly used nozzles, etc.

 

 

 

(2) Nozzle selection support (PIN)

 

 

 

When the nozzle is selected, the nozzle selection support is used to position the nozzle to prevent it from falling off. Long-term operation will cause wear or deformation of the nozzle selection support (PIN), resulting in poor positioning of the nozzle. The machine will malfunction and cannot perform normal production. It is necessary to check or replace the nozzle selection support (PIN), as shown in the figure below.

 

 

 

 

 

2. Typical sensors

 

 

 

The selected placement machine is composed of many parts. Its operating conditions require many parts to operate in a normal state. How to know that each component is under normal operating conditions? sensors to accomplish this mission. The status of each component is detected through sensors, and then the information is transmitted to the control part for display, telling the operator whether the equipment can be run. If the equipment cannot be run, an error message will be displayed, and the operator will follow the prompts to troubleshoot so that the equipment can operate. normal operation.

 

 

 

There are many sensors in the placement machine equipment. Before deciding on the number of sensor spare parts, first figure out the types of sensors in the entire machine and their distribution throughout the machine. They can be classified according to use or by machine part. For example, there are 5 major categories according to parts: safety sensor, drive unit, rotating head and others, upload rail and download rail unit, and component supply unit/feeder, etc. Clarify the working principle of each category to determine the type. Whether the sensor is easily damaged, etc., and finally determine the weight and quantity of sensor spare parts. For sensors that are easily damaged, you should buy more.

 

 

 

3. Unit head of turret equipment

 

 

 

The unit head of the turret equipment is also easily damaged. If there are no spare parts, it will be very expensive to buy them after they are damaged, and the purchase cycle will be long. If there is a spare unit head, when a problem occurs during production, the unit head can be removed and a new unit head installed. At the same time, the faulty unit head can be inspected and debugged below without affecting production. By analogy, for modular components, you can also purchase more spare parts. Generally, each placement machine needs to purchase 3 to 4 unit heads as spare parts. This method is often used in large-scale production.

 

 

 

4. Adjust the tooling fixture

 

 

 

After each piece of equipment is produced for a certain period of time, the origin will deviate, and the placement accuracy needs to be calibrated. Calibration requires certain tools and means, that is, certain calibration fixtures and fixtures (some companies call them fixtures), etc. Among the options, be sure to have such tools and jigs. Equipment buyers often ignore this part or are unwilling to spend money on this aspect, which is very important to ensure long-term and stable operation of the equipment.

 

 

 

5. Control panel

 

 

 

The control board is the brain of the placement machine. It collects various information and then issues corresponding instructions to the computer based on the collected information, so that the placement machine can perform placement as required.

 

 

 

Generally, the control boards of the placement machine are concentrated in a control box, mainly including:

 

① Power control board;

 

②CPU control board;

 

③FD/VGA control board, used for computer floppy drive, keyboard and hard disk inspection and control;

 

④ I/O control board for input, output and printing control;

 

⑤ NC control board, used to control moving drives such as X, Y, H, ZL/ZR, VT/MT and CT (identification camera compensation);

 

⑥ SC control panel, control timing, track width and sub-keyboard;

 

⑦ RC control board, used for identification control, PCB identification, component photography and LED control;

 

⑧ MMC control board, used to control the stepper motor θ on the upper part of the turret.

 

 

 

The control board is composed of printed circuit boards and components. It also requires a certain working environment. It is necessary to regularly check whether the cooling fan is operating normally to ensure normal heat dissipation. It must also be cleaned regularly to maintain the normal operation of the control board and extend its life.

 

 

 

6. Electric motor

 

 

 

The motor is the power source of the equipment. If the equipment motor cannot work, the entire equipment cannot work. The quality of the motor is related to the maintenance of the equipment. It is necessary to ensure the cooling system of the motor, ensure the working environment of the motor, clean and maintain the motor regularly, and repair or replace it in time if there is any abnormality. The motors used on patch machines include: AC motors, stepper motors and DC motors. For example, the main motor is the power source of the equipment; the servo motor (or stepper motor) is the control motor for X, Y, and Z; and the power motor used to transport the printed board is a DC motor.

 

 

 

7. Other electromechanical parts

 

 

 

(1) Filter

 

 

 

The filter filters the compressed air used during the patching process to ensure the cleanliness of the compressed gas. If the filter is dirty and the filtration effect is not good, it will affect the suction of the nozzle and directly affect the patching effect. During equipment maintenance, filters are required to be replaced regularly, generally once a month, and are consumable items. Therefore there must be certain spare parts.

 

 

 

(2) Reflective plate and reflective cap

 

 

 

The reflective plate is used to detect component size, component electrode and nozzle number. When the above three types of identification failures occur during the patching process, the reflective plate and reflective cap must be inspected or replaced.

 

 

 

(3) Conveyor belt

 

 

 

Conveyor belts are used to transport patch products. The conveyor belt will wear out during long-term use and will break after a certain period of time, and it will need to be replaced. It is necessary to have at least 1 spare part, and there may be two copies for parts that are frequently worn.

 

 

 

(4) Cylinder

 

 

 

The cylinder is generally used in conjunction with the solenoid valve in the placement machine to play the role of lifting and stopping. In the mechanism of the placement machine, cylinders are widely used. For example, the cylinder used on the placement head can set whether the placement head is used and complete the stopping function; the rise and fall of the placement worktable is performed by the cylinder according to the signal of the solenoid valve. Telescopically raises and lowers the workbench. The cylinder will be worn and dust will enter during use. It should be checked regularly and problems should be dealt with promptly. If the cylinder is inflexible or not in place due to unclean compressed air, it must be cleaned. If there is air leakage, it may be a seal. If the ring is aging, replace the sealing ring; if it is due to piston wear, then the cylinder must be replaced.

 

 

 

(5) Bearings

 

 

 

The function of the bearing has two aspects, the first is to limit the position, and the second is to support. Bearing limit means that the fixed shaft can only rotate, but cannot move axially and radially; support means that it bears the radial load of the shaft. Bearings are divided into rolling bearings, radial bearings, ball bearings and thrust bearings according to their functions.

 

 

 

Bearings are widely used standard parts in the structure of placement machines. They require smooth operation. If they run for a long time, they will be worn. They must be checked regularly. If the bearings are found to have radial movement, which affects the normal operation of the equipment, timely inspections must be carried out. replace. Such as spherical bearings and rolling bearings used in placement machines.

 

 

 

(6) Timing belt

 

 

 

The synchronous belt drive is composed of an endless belt with equally spaced tooth shapes on the inner circumferential surface and corresponding matching wheels. It combines the advantages of belt drive, chain drive and gear drive. When rotating, power is transmitted through the meshing of the belt teeth with the tooth grooves of the wheel. Synchronous belt transmission has an accurate transmission ratio, no slip, can obtain a constant speed ratio, has stable transmission, can absorb vibration, has low noise, and has a large transmission ratio range, generally up to 1:10. The allowed linear speed can reach 50 m/s, and the transmitted power ranges from a few watts to hundreds of kilowatts. The transmission efficiency is high, generally up to 98%, the structure is compact, suitable for multi-axis transmission, no lubrication is required, and there is no pollution, so it can work normally in places where pollution is not allowed and the working environment is harsh.

 

 

 

On chip placement machines, synchronous belts are generally used for the rotation of theta angle and the transmission of the main shaft. They will wear out over a long period of time and need to be inspected and replaced regularly to ensure the normal operation of the equipment.