How to realize the quality and efficiency of SMT tin printing, and by what method?

I. Operating Specifications for SMT Material Operators

1, order view

After receiving the order, the material clerk needs to check the contents of the order in detail, especially the matters needing attention. Learn about scheduling from PC and material preparation from warehouse. Pay special attention to the shortage of materials, make records and report to the supervisor.

2. Picking

Ensure correct specifications, accurate quantity and timely delivery. All delivery vouchers should be kept intact. Alternative materials should be seen in the written documents of the project, and oral forms are not accepted. See SMT material control measures for specific operation methods.

Step 3 distribute materials

For Class A materials such as integrated circuits, distribution should be timely and accurate, especially for night shift materials. It is necessary to check the night shift production plan before distributing materials. Matters needing attention in the use of materials (such as alternative materials, shortage of materials, how to allocate the number of IC, etc.) should be clearly stated. ).

4, material room control

All materials should be placed on the material rack and clearly classified. Inventory quantity should be controlled in time, especially for the parts with material shortage. Nests should be placed in plastic frames and clearly marked. The material room should be well guarded against theft and locked at any time. After work, the key is given to the night shift staff to extend the control time.

5. Feeding

For the IC lost by the operator, the material supplement sheet should be opened immediately (it should be handed in when paying the bill), and for other materials, it is usually supplemented once every Friday. For the machine loss part, it is necessary to grasp the loss quantity in time and replenish materials in time.

6. Storage

All PCBA should be clearly classified and marked with clear quantity, especially ROHS products. Make accounts in time after each warehousing to ensure clear control. Generally, it is updated twice every morning 10 and evening before work. All storage documents should be kept intact.

7. Inventory

At the end of each month, make material inventory with the warehouse at the same time.

8. Make accounts

The import and export of materials need detailed accounting records, including orders and machine types. Including picking, issuing, replenishment, warehousing, etc.

Second, SMT inspectors operating specifications

1. First article confirmation

For the first board at the beginning of each shift or after product switching, the intermediate inspection must be carried out together with the first appearance inspection, taking the engineering sample as the reference standard. The inspection contents include: part direction, part polarity, deviation, missing parts, wrong parts, multiple parts, more tin, less tin and even tin. If any problems are found, they should be reported to the extension department in time and sent to IPQC for confirmation after the first inspection is correct.

2. Hand swing parts

Hand ornaments are carried out under an elongated arrangement. The material specification, location, quantity and direction of the jewelry must be confirmed by IPQC before the jewelry starts. And fill in the manual maintenance report. All the ornaments must be intact before passing through the furnace.

3. Handling of lost circuit boards

In principle, the missing plate is not allowed to pass through the furnace, and can only pass through the furnace after obtaining the extension consent, and fill in the record of missing plate passing through the furnace. Especially the lack of class a materials such as IC. And mark the corresponding position on the plate to inform the inspectors after the furnace of the material specification, quantity and the location of missing parts.

4. Hold the board

In order not to affect the production efficiency, the intermediate inspector should observe the plate discharge of the machine in time and take out the plate on the belt in time. In addition, handle the circuit board gently, don't take off the parts, hold the edge of the circuit board by hand, and don't wipe off the parts or solder paste.

5.PCB inspection

After PCB parts are attached, inspectors should carefully check whether there are any defects, such as inversion, deviation, missing parts, wrong parts, multiple parts, more tin, less tin and even tin. If three identical defects appear continuously, they should immediately report or extend the defects to the operator. Operators should remember the places where PCB does not need to be punched to improve work efficiency.

6. Furnace

When checking the OK plates passing through the furnace, it should be noted that the interval between plates is about 30CM to prevent tin from not melting. In addition, for the board with double panels or golden fingers, it must be padded with paper to pass through the furnace. The size of the paper should match the board, and it should not be too big or too small to avoid being blown off by the wind in the furnace. In addition, it is necessary to wait until the temperature of the reflux furnace is enough before passing through the furnace.

7, playing * board processing

In the process of stamping plate production, if it is found that there are parts attached to the stamping plate or parts with good plate attachment are missing, the inspector of intermediate inspection should report to the stretcher and operator in time. Missed pasting boards are not allowed to pass through the furnace, and parts need to be pasted again; If the board has been pasted, it is not allowed to pass through the furnace, and the pasted parts need to be removed for later use.

Three, SMT furnace visual inspection personnel operating specifications

1. First article confirmation

For the first board at the beginning of each shift or after product switching, the appearance inspection after furnace must be the first appearance inspection, taking the engineering sample as the reference standard. The inspection contents include: part direction, part polarity, deviation, missing parts, wrong parts, multiple parts, more tin, less tin, tin connection, vertical parts, false welding and cold welding. If any problems are found, they should be reported to the extension department in time and sent to IPQC for confirmation after the first inspection is correct.

Step 2 pick up the board

In order to prevent the plate from falling off or knocking off parts, the visual inspector after the furnace should check the plate taken out of the reflow furnace in time and pick it up in time.

3.PCBA layout

All PCBA behind the furnace must be placed on the insert plate, and the insert plate must be placed neatly in the designated area. OK products and NG products are placed on different boards respectively. Different types of circuit boards are placed on different circuit boards.

4, missing parts (scrap) plate processing

If there is a missing plate behind the furnace, it should be reflected in the elongation rate in time and recorded in the Record Form of Missing/Discarded Plate Behind the Furnace. Repairing scrapped plates, or stamping plate patches or missing good plate patches, should reflect the lengthening in time, and record it in the missing parts/scrap record table behind the furnace.

5.PCB inspection

After the PCBA passes through the furnace, the intermediate inspector should carefully check whether there are any defects such as parts upside down, offset, missing parts, wrong parts, multiple parts, more tin, less tin, even tin parts, false welding and cold welding. If three identical defects appear continuously, they should be reflected in the elongation in time. Operators should remember the places where PCB does not need to be punched to improve work efficiency.

6, after the furnace inspection report

All defective products should be clearly and truly recorded in the production inspection report.

7, check

In principle, for a circuit board with good appearance, the operator should collect a plug-in board or an integer for inspection. For urgent orders, 50 pieces should be sent for inspection, and the required content (ID card) should be clearly marked when sending for inspection. Good board and punching board should be sent for inspection separately.

Four, SMT operator operation specification

1, first feeding and model switching

The machine operator feeds materials according to the bill of materials in the production procedure, so as to keep the materials (plates), the machine procedure and the material table consistent. After receiving the transshipment notice, the operator should prepare the materials in advance and install the feeder. In principle, it is not allowed to wait until the last model is produced before loading, except in special circumstances.

Step 2 come on

Operators should always check the use of machine materials. When the materials are almost used up, he should inform the helper in advance to take them away and put them aside for later use. When replacing materials, materials (plates), machine procedures and material list should be consistent. Fill in the refueling record form after refueling and notify IPQC for confirmation.

For materials packed in pipes or trays, pay attention to the direction when loading, and thoroughly check the direction before loading. If you are not clear, please call a technician for handling.

3. Feeder use

Feeder is an expensive accessory and can't be stacked. It can only be placed on the feeding car, and the front cover of the material belt should be closed at any time. Whether the feeder is installed on the vehicle or the machine, it must be installed in place, especially when it is installed on the machine, the impurities on the table should be removed before installation.

In addition, the feeder model should be selected according to the belt width, and the feeding distances of 12MM and 16 mm should be adjusted according to the belt spacing. Please refer to the equipment operation guide for detailed usage.

4. Materials

Time schedule of material adjustment: morning shift (first inspection), model change, material replacement, afternoon shift and evening shift (final inspection). Material alignment method: make the material (CD), machine program and material station consistent.

5, machine safety operation

SMT equipment belongs to expensive equipment and needs safe operation. At the same time, operators should also pay attention to their own safety. Please refer to the equipment operation guide for detailed operation methods.

6, material loss control

The operator should strictly control the material loss, especially the material loss of Grade A.. When the machine throws material seriously, it shall promptly notify the technicians to solve it. In principle, if more than 5 pieces are thrown, please inform the technicians to adjust the machine. At the end of each day's work or before model switching, record the quantity of materials thrown by the machine in detail.

7. Class A material control

For materials loaded by belts, operators should be familiar with the use of feeders to reduce losses. For materials packed in pipes or trays, they must be placed in a stable position to prevent parts from falling off. Any loss of Grade A materials shall be recorded in the Precious Materials Handover Sheet in detail and truly. Do a good job of material inventory in advance when you get off work and prepare for handover.

8, put on the board

If the operator doesn't know the direction of placing the plate, he should call the technician to handle it in time. When placing the board, you must confirm the direction before placing the board. Don't put too many boards on the belt, and there must be a certain distance to prevent two boards from entering at the same time.

9, playing * board tape

For the perforated plate, the operator should pay attention to the position of the adhesive tape. If it is not clear, please ask the technician. It is not allowed to leave out or paste in the wrong place. If the machine identification is wrong, the technician should be informed in time for handling.

10, output statistics

Record the hourly output on the statistical table, the downtime on the statistical table, and the output every two hours on the bulletin board. If there is IC, the output is based on the number of IC used, and if there is no IC, the output is based on the number of circuit boards actually produced.

Five, SMT solder paste printing machine operation specification

1, printing quality control

Printers should be responsible for the quality of printed boards, and cannot pull down boards with tin, less tin and more tin.

2, steel mesh protection

Printers should be careful when using and installing steel mesh. Don't put the stirring knife on the steel mesh to prevent damage to the steel mesh and scraper when the scraper is pressed down. Special attention should be paid to the placement of thimbles, and other sundries except thimbles should not be placed under the steel mesh.

3. Cleaning and storage of steel mesh

After each use of steel mesh, the surface, side and steel mesh should be carefully cleaned, especially the steel mesh should be cleaned with a toothbrush to prevent it from being blocked by solder paste and affecting tin. Steel mesh should be stored on the steel grating, with the marked side facing outward for easy searching.

4, the use of solder paste

The use of solder paste should strictly follow the guidelines for the use of solder paste, and only one third of the bottle can be placed on the steel mesh at a time. After 4 hours of printing, it should be recycled and stirred again. Solder paste bottles should be scraped clean to prevent waste. Attention should also be paid to the complete recovery of solder paste on steel mesh and scraper.

5. Printing plate cleaning error

For the cleaning of printed circuit boards, first use a stirring knife to scrape the solder paste on the surface of the circuit board, but be careful not to use too much force to prevent scratching the PCB, then wipe the surface of the circuit board with cloth or paper dipped in washing water and pay attention to wiping it clean. Then blow dry the PCB with an air gun. For PCB with gold fingers, pay special attention not to immerse the board in board washing water, but only to wipe it with cloth or paper dipped in board washing water, and don't wipe the gold fingers. Gold fingers can't stick solder paste.

6, printing machine cleaning

Printers should clean the printing machine at any time to keep the machine clean, especially don't stick solder paste or marks everywhere.

7, steel mesh installation

For the installation of steel mesh, the printer should pay attention to the one-time installation in place, and master the installation skills and methods, especially the fixing of PCB, which must be fixed to increase the repeatability of printing.

8, equipment safety operation

For the use and safe operation of the printing press, please refer to the equipment operation guide. If there is any abnormal situation, please press the emergency switch immediately to prevent the machine from hurting people. Especially the scraper is sharp, so the operation should be gentle. When cleaning the wire mesh, be careful not to be cut and crushed by the scraper.

Six, SMT repairman operation specification

1, check the soldering iron temperature every day, and the temperature range is 320 20℃

2. Strictly distinguish between lead soldering iron and lead-free soldering iron. Before repair, ask about the elongation and what kind of soldering iron to use to repair PCBA.

3. If the defective parts are missing parts, wrong parts, poorly marked parts, etc. , and the components need to be replaced again, the maintenance personnel should go to the rack or machine according to the component specifications marked in the position map, and ask the operator to help find the required components, which can only be used after being confirmed by the duty extension /IPQC.

4. The stop time of soldering iron contacting all parts is not allowed to stay for more than 5 seconds continuously.

5. Generally, the repair in the same position shall not exceed 3 times.

6, pay attention to the time and temperature when repairing, don't burn out parts and PCB.

7, pay attention to personal safety when repairing, to prevent the electric soldering iron and hot air gun high temperature parts touch the human body.

8. When the repairman leaves, pay special attention to the electric soldering iron and hot air gun should be put back in place to prevent burning out other items.

9, the repairman should remember to turn off the electric soldering iron and hot air gun power when off work, to prevent fire.

10. When closing the hot air gun, turn off the heating switch first. 10 minutes later, turn off the blowing switch to prevent the internal damage of the hot air gun.

Seven, SMT technician operation specification

1 equipment maintenance

Technicians are responsible for the weekly and monthly maintenance of all equipment in the workshop, and at the same time supervise employees to carry out daily cleaning work.

2. Equipment operation

Technicians should adjust the equipment at any time to ensure the normal operation of the equipment.

3. programming; arrange

When programming, technicians should ensure that they compile well at one time, and they can't be wrong, less, more or with the wrong polarity. At the same time, ensure that the program is optimized to improve efficiency. For the modified program, you must go back and change it, and then optimize it. You can't change it directly on the extension to prevent future mistakes.

4, machine throwing control

Technicians should observe the throwing situation of the machine at any time and adjust the machine in time to reduce the material loss of continuous throwing.

5, operator training and management

Technicians are responsible for training and supervising operators, and should promptly remind operators of improper operations and correct them. Especially the safe operation and personal safety of the machine.

6, furnace temperature test

The technician is responsible for the furnace temperature test at least once a day, and names the documents according to the date. Pay attention to adjust the temperature to ensure the welding quality of PCB.

7. Online quality control and efficiency improvement

Technicians are responsible for all quality control of the production line, focusing on monitoring tin printing, machine operation, reflow soldering and maintenance stations. The mounter should be debugged to the best condition to reduce downtime, refueling time and fault alarm rate.

Eight, SMT extended operation specification

1, on-site discipline maintenance

According to the management requirements of the factory and workshop, Elongation shall keep the discipline of the work site at any time.

2. Site 5S management

For the 5S management of the workshop, the personnel should be arranged reasonably for sorting and cleaning. It is necessary to monitor and correct the accessories of electrostatic clothing, hats and wristbands at any time.

3, on-site personnel operation standard supervision

According to the established post operation specifications, the extension department shall inspect the site at any time.

4. Production execution

Arrange production reasonably according to the schedule and improve production efficiency.

5. Material control

All SMT personnel are strictly required to manage and hand over materials according to the detailed rules of material control and operation specifications, so as to prevent material loss and reduce losses.

6, production efficiency control

Supervise employees to master methods according to operating specifications and improve efficiency.

7. Product quality control

Elongation is responsible for the quality control of the whole production line. If any abnormality is found, technicians are required to handle it at any time and report the defective materials to the supervisor at any time. And is responsible for tracking the correction results.