Picking -PCB baking -PCB loading-solder paste printing-patch installation -IC patch -92 visual inspection-reflow oven-visual inspection -fqc- warehousing.

Second, the production line refueling method and the required time

According to the remaining situation of materials at each station on the platform, the operator has six good materials to go online in the material area, and the materials on the platform are: When the production is completed, the prepared materials will be transferred to the machine. When changing materials, clear IPQC to check the materials and make feeding records. It takes about 15 seconds to change and align the material.

Thirdly, the production schedule of our SMT workshop is arranged in advance (one week) by the production management department.

4. Our warehouse collects all materials in advance (two days) according to the schedule. According to the batch size of the work order, it will be assigned to the production line.

Five, in order to save time and improve production capacity, there must be two sets of materials on the production line:

1. Materials in production.

2. Materials for the next work order (prepare one day in advance and confirm OK).

6. Printer, how to print the substrate and the time required to print a board?

A: First of all, when you get a board, you should check whether the substrate is defective. If it is, just pick it out. If possible, put it into the printing machine-print-check the printing quality, and put it into the next station. * * * It will take about 15-20 seconds.

Seven, the balance of machine running time

According to the number and types of components on the substrate, the components are evenly distributed on high-speed machines and general-purpose machines, and the time spent sticking a line on each machine is consistent, so as to ensure that the machines will not be in a stagnant waiting state in production.

Eight, reflow oven conveying speed setting

The setting of the transfer speed of the reflow oven is determined according to the time for the mounter to produce the circuit board and the length of the substrate.

Board length ×60 seconds

Transportation speed: ——————

The number of seconds to produce the substrate.

Nine. Distribution of visual inspection work

Each line is equipped with three inspectors. The basic division of labor is: the first station cover plate checks the missing parts, multiple parts and ic direction, and the other two are assigned by the production line cadres to check other defects of half the components on the substrate.

X. When production lines C, D, E, F and G produce products in the process of adding glue and tin, how will the production line staff be distributed?

Answer: Because there is no glue dispenser on lines C, D, E, F and G, after printing solder paste, the substrate needs to be transported to line A or line B for glue dispensing operation, and the quality of glue needs to be comprehensively checked. Because the solder paste is divided into two parts, R and C, there are few defects, so the visual inspector should draw one to assist in printing and checking the red glue, so as to facilitate the smooth operation of the production line.

1 1.PCB baking time (4 hours) and heating time (2 hours).

IC baking time (3 hours), heating time (2 hours).

BGA baking time (10 hour) and temperature return time (2 hours).

The above operations need to be prepared in advance to avoid delaying the production process.

Lead-free manufacturing process

One: Lead-free process not only requires lead-free solder paste, but also requires PCB pads and electronic components to eat tin.

Two: What is the main difference between lead-free and lead-free?

Lead-tin paste contains harmful substances such as lead and cadmium, which is very harmful to human body and environment.

Lead-free solder paste has no adverse effects on human body and environment at present.

Three: the maintenance of lead-free products requires soldering iron temperature of 235~240℃.

Name two kinds of lead-free solder paste.

MT05-GIN360-KJ

L2493-5LFH0 1-E。

Please draw a profile of high temperature lead-free process.

Please draw a low-temperature lead-free process profile.

7. Pass the high and low temperature lead-free solder paste through the reflow oven for a set temperature and time.

1, lead-free at high temperature

A. Preheating temperature: 150 degrees for 90 seconds and 30 seconds.

B, welding temperature: 235 ~240 degrees

Time 10 sec ~ 30 sec

2, low temperature lead-free

Preheating temperature:100℃ ~150℃ for 60 30 seconds.

B, endothermic temperature:150℃ ~ 210℃ for 40 10 second.

Welding temperature: 225℃~230℃ for 30 seconds.

8. How can the printing station avoid distinguishing lead from lead and prevent lead-free solder paste from mixing with lead-free solder paste?

1. Clean the scraper with ultrasonic wave.

2. Wipe off the residual lead-tin paste in the print head.

9. How can a repairman tell lead from lead?

1. All reworked products must be reworked with lead-free tin wires.

2. Lead and lead-free ferrochrome can be distinguished.

X. How to distinguish lead and lead-free products?

1. Qualified products must be divided into lead product placement area and lead-free product placement area.

2. Separate lead-containing products from lead-free products.

3. Lead and lead-free vehicles will be marked when they are put into storage.

Work research

1. What are the priorities of engineers?

1 Edit, debug, save and keep the program.

2. Prevent quality abnormality, research and improve through quality analysis.

Machine troubleshooting and equipment maintenance.

4 program optimization and productivity improvement.

5 deal with emergencies such as chlorine stoppage and power failure.

6. Cooperate with the production line to keep the production running smoothly.

2. Which is more important, quality or productivity?

Both are important.

B quality

capacity

Third, the relationship between quality and productivity?

A If you want to do quality well, you have to sacrifice productivity. If you want to do a good job in productivity, you must sacrifice quality, quality and productivity. You can only focus on one picture, because they are opposite.

B there is no contradiction between quality and production capacity. The better the quality, the higher the productivity.

4. What is the cause of short circuit?

1. Too much solder paste or printing tin.

2. Printing inaccuracy and deviation.

3. The solder paste collapses

4. The scraper pressure is too high

5. Improper solder joint design

6. The gap between the steel plate and the circuit board is too large.

The verb (abbreviation of verb) causes the formation of tin beads:

1, solder paste collapse,

2. Too much solder paste

3. Poor printing quality

4. Types of solder paste

5. Temperature curve

Six, the reasons for the formation of standing goods:

1, improper solder joint design

2. The two ends of the component have different tin-eating characteristics.

3. The points at both ends of the part are uneven

4. The temperature curve is added too quickly.

5. The through hole next to the solder joint will lead to standing.

6. Part installation deviation.

Seven, the causes of SMT parts with feet virtual welding.

1. The feet of the parts are uneven or convex.

2, too little solder paste.

3, parts feet don't eat tin.

4. Solder paste pollution.

8. What are the reasons for empty soldering of 8.SMT parts without feet?

1, improper pad design.

2. The pads at both ends are uneven.

3. The amount of solder paste is too small.

4. The parts are poor in tin.

5. glue.

6. Installation offset

7. Solder paste is contaminated.

What do you think of your job as an engineer?

The answer is not fixed.