DIP plug-in post-welding production process training materials of the plug-in post-welding factory
Production flow chart of plug-in line in plug-in post-welding processing plant
DIP plug-in post welding production flow chart
1. After the plug-in welding processing factory DIP plug-in welding and the preparation before production
Material preparation:
1. The material personnel of the production line fill in the material requisition form according to the work order and BOM, and go to the material warehouse to receive the materials required for production in advance.
2. The material personnel shall schedule according to the production plan, prepare all the materials needed for production in advance, and carry out pre-processing before production according to the sample provided by the customer.
Plastic surgery:
Some parts need to be trimmed in advance due to body design or plug-in requirements and overall PCB planning. Require:
1. Shaping: The horizontal width of the pins of the rear part is equivalent to the width of the positioning hole, the tolerance is less than 5%, and the characters are upward.
2. The pin extension of the part: the distance L from the top of the pin of the part to the PCB pad (greater than 1.0MM, less than 2.5MM).
forming:
1. When the non-support hole parts need to leave the board surface (power resistance above 2w, etc.) or the customer needs, the parts need to be formed to provide mechanical support and prevent the pad from lifting.
2. The minimum distance between the parts that need to leave the board and the board is 1.5mm.
Points to note for plastic surgery and molding:
1. The minimum inward bending radius when the part is bent: 0.8-1.2mm
2. The damage should not exceed 10% of the diameter, and there should be no jagged indentations.
Second, the post-plug-in welding process factory’s pre-plug-in preparation
1. OP arrives at the designated station according to the arrangement of the line length; preview the WI content of the station in advance, and receive the parts with the same material number as on the WI.
2. Put the received parts into the material box, and then paste the part number label and the defective product label on the material box.
3. Check whether the parts have polarity, then compare with the pictures on the WI to familiarize themselves with the appearance of the parts, and find out where and where the parts are placed.
DIP plugin
Three, plug-in post-welding processing factory plug-in operation content:
1. OP wears ESD protection equipment such as electrostatic wristbands, finger cots, etc. according to the operation method specified by WI; insert the parts that need to be placed in the station to the corresponding pins of the PCB of the assembly line, and pay attention to the polarity of the parts. The parts installed close to the board surface should be placed flat against the board surface; the minimum distance between the parts installed away from the board surface and the board is 1.5mm.
2. Gently press the parts with your hands to ensure that the parts are placed in place; and check whether the parts are raised, skewed, extremely reversed, folded feet and other defects.
3. The plug-in inspects the components, and promptly removes the wrong components and defective components (including the components with poor shaping effect.
Fourth, the placement requirements of the parts in the post-welding processing plant of the plug-in
1. Resistor components close to the board surface should be placed close to the board surface; the pin extension meets the requirements of the company’s specified documents.
2. For the parts that need to be installed away from the board surface, the distance from the board surface is at least 1.5mm, and the non-supporting hole must be formed in advance when placing the parts. (The minimum acceptable standard is 1.0MM)
3. For parts with multi-pin support shoulders, when installed on the motherboard, the bottom surface is parallel to the board surface, and the support shoulders of all pins are close to the pad.
4. The limit device used to mechanically support or offset the weight of the component must be in full contact with the board surface.
5. When the silk screen frame of the part is horizontal, the part must be flat against the board surface, and at least one side must be flat against the board surface.
6. The interface parts must be installed flat against the board surface.
Five, the understanding of the polarity of parts
1. SMD capacitors, resistors, resistors, capacitors, plug-in resistors, ceramic capacitors, etc. have no polarity.
2. The “+” mark next to the electrolytic capacitor silkscreen frame indicates the positive electrode of the capacitor, and the “-” on the electrolytic capacitor silkscreen indicates the negative electrode of the capacitor. Pay attention to the polarity when plugging in.
3. The transistors are all polarized, so pay attention to the direction when plugging in. The polarity of the diode is marked: “+” means positive pole, and “-” means negative pole. Polarity mark of the triode: The triode should be placed according to the silk screen, and the cut direction of the part body is the same as the cut direction of the silk screen frame.
4. Chip polarity mark: The chip’s notch or dent on the chip body package is the polarity of the chip, and the polarity of the plug-in should be the same as the polarity of the silk screen on the PCB.
Six, clean
After the wave soldering furnace is dirty, clean the motherboard with a cleaning agent to remove the dirt.
Seven, cut the feet
Use cutting pliers to cut off the parts whose pins extend beyond the specified range. Be careful not to scratch the PCB board with the cutting pliers.
Electrical test
Eight, electrical test
Conduct electrical tests on the motherboard according to requirements, measure the specified pins or pads with an electric meter to check whether the PCB board is short-circuited, open-circuited, etc.
Nine, visual inspection
Visually inspect the motherboards on the assembly line, lay down the motherboards with defective appearance, record the reasons for the defects, and send them for repair.
Ten, bad repair
Repair the motherboard with poor appearance. Pay attention to the temperature and soldering time of the soldering iron and the intensity of use when repairing, and take care not to touch the soldering iron to other places on the PCB.
Eleven, welding
Some parts cannot be passed through the wave soldering furnace, so manual welding can only be carried out behind the furnace. When soldering, you need to solder the specified pins according to the content of WI. When soldering, you need to pay attention to the following points: the amount of solder used, the time of soldering, and the appearance after soldering.
Plug-in wave soldering
Twelve, the use of soldering iron
1. The new ferrochrome tip should be tinned before use to prevent oxidation of the ferrochrome tip and prolong the service life of the soldering iron. Before using the ferrochrome, add water to the sponge in the ferrochrome frame to keep the sponge moist (the sponge is just squeezed with water droplets) to prevent the sponge from burning.
2. When the ferrochrome is dirty, first pick up the ferrochrome and wipe it at the edge of the sponge to remove the oxide of the ferrochrome head, and then use; the tin slag and dirt on the ferrochrome should be wiped to the sea of the ferrochrome frame. For the cotton edge hole, it is forbidden to shake or knock with chrome iron. After the ferrochrome is used up, tin is added to prevent oxidation, and then the ferrochrome is placed on the ferrochrome rack.
3. The use temperature of ferrochrome: lead soldering temperature is 330℃±10℃, soldering time is 3~5 seconds; lead-free soldering temperature is 380℃±10℃, soldering time is about 3 seconds.
4. Precautions for manual welding
a. The soldering iron must be grounded before use to prevent leakage;
b. Keep a distance of at least 25cm between the welding place and the human nostril and wear a mask;
c. Wear electrostatic wristbands and gloves to ensure the ventilation of the venue;
d. Cover the bottle cap immediately after use of flux, cleaning agent, etc. to prevent volatilization in the air (affecting health and causing waste). If not in use, tighten the bottle cap;
Thirteen, packaging
Some models are not assembled in the factory, and the veneers need to be packaged when they are shipped. OP puts the motherboard into the bubble bag according to the method specified by WI, and then puts the motherboard into the carton. After filling a box, OP will paste the printed certificate on the box.