Years later, because the epidemic blogger waited until March 6 to go to work as an intern, it is now the second month. This month I feel that I have done a lot of things. Unlike the first month, I just do a lot of things. I draw the PCB of the big brother project and understand the company ’s products. I actually did the project this month. Complicated, even thinking about being fired or squid, fortunately adjusted. One by one.
The first is the first self-signed project in life. Now it seems simple is simple, but there are many pitfalls.
Let me introduce this project, it is not difficult, in fact, the structure of the original product has been changed. He and other engineers got the information of the project and looked dazed. The schematic diagram and PCB are not right, there is no IC data, the PCB is really bad, and there is no standardization. This is to lay the groundwork for the problems that have occurred this month. There is no way to reverse the schematic diagram from the PCB, because the PCB is in mass production, there must be no problem. The pit is coming. When the meeting said that the original chip was not produced, the 8000R was used as 8000V, so I had to re-board, and then I forgot to send it out for proofing. It took a week to know that the project was in a hurry. In a hurry, I slept three hours a night and found various ways. Because it is Shenjin's craft, it will take 3 days to proof the Allegro, and the price is expensive. The next day, there was no way to send out the board. The master said to PM that the circuit was changed and the board was restarted. These days I was really afraid of death and thought a lot. A few days later, when I went to burn the program, the original engineer said one thing that made me mad. The PCB draws an 8000R package (38 feet), but he said that he used an 8000V chip (34 feet). At that time, it was really speechless. I took the first board to burn the program and realized the function, but I found another problem, that is, there is no correspondence with the structural engineer. The gold finger is reversed. PCB board three times. In the end, I finished the board. The proofing case on the other side of the structure has not yet returned, and it took a few days before the prototype was assembled for business. The BOM has been updated N times.
The gold finger is reversed, flying the wire to an empty board.
This project is believed to be memorable for life. I have learned the importance of data norms, both for others and myself. The second is that communication is not good. Especially that night I thought that if I did n’t send it out, I would never forget it in my life.
The second project is not difficult. The first problem occurred during soldering. I soldered 0402 resistors and capacitors, a total of 6 PCBs, and there was a virtual soldering. It took a long time to find out the problem. The second problem is that there is always a problem when measuring impedance. It is a very strange problem that has not appeared before. Then I have no problem with the hardware detection, but I can't find it, and then I have been checking with the master and the software engineer. It has been checked at 7:30 in the evening. I really can't find the problem. The level is not enough, it is related to the problem of IC. I don't understand it at all, I want to find a supplier, so I got off work. Now think about yourself, this is really wrong, you should continue to study, less patience. The next day, I asked whether it was solved. I was caught for a while, and then it was a software problem. A variable was wrong. Alas, I do n’t know what to say. The third problem is the problem of Bluetooth. There are many methods of life and death. The software engineer found that the schematic diagram is wrong. The error is reversed on the two feet of the Bluetooth IC. The schematic library is wrong. For that project, the information is not good. My own problem is that I did not look for the Bluetooth data sheet during the design. In the future when designing the circuit, I have to be very careful and seeing is believing.
The red component is 0402, soldering 6 PCBs, seeing my dazzling.
The third project is to directly add a Bluetooth to the previous project, just to proof the PCB, it seems simple, but it also fell into the pit. The first is the problem of Bluetooth PCB design,
Here, I didn't make holes in the middle GND, so it always caused problems when welding with a hair dryer, and various situations occurred. The firmware can't be burned in. I have soldered two or three boards and the success rate is very low. The second is that I didn't actually think about the burning point.
It is not good to put the burning point here, the actual soldering burning line is that the soldering iron head will touch other components.
When I actually did it, there was a problem of excessive power consumption. I checked it for a long time and the hardware was correct. Then I couldn't ask the master. I suspected that there was a problem with the supplier's binding. So re-bundling the PCB, this time when I first came back and soldered the main IC, no problem, everything is normal. After welding other, it still consumes a lot of power. Take a closer look, there is no virtual welding. I really can't figure it out. I used the most stupid way to remove the components that might eat the current one by one to see it. As a result, I really found the problem and solved it.
The actual programming point is stuck between the bonded wafer and the resistor.
There are other projects this month that will not be covered in the design schematic and PCB design.
Summarize the lessons learned. The first one is definitely welding. Basic 0603 is quite skilled in welding. At least there is no burr like the first month. There is also welding 0402. After welding 0402, welding 0603 is found to be very large. There are other ICs that are really simple. Except for some ICs that use a hot air gun, this kind of IC is really difficult to mount and is also related to PCB design. The second is the standardization and correctness of the data. This is really important, otherwise it will kill others, so I made the company's principle library and PCB packaging. The third is to learn how to compare the drawings with structural engineers. Special components should really correspond, such as gold fingers, and for convenience of production, where should the external circuit board and sensor pads be placed, preferably every time The design is given to the structure and imported into the model. There is also the need to communicate well when taking over other engineers ’projects. Even if he is relatively indifferent and difficult to communicate, at least all the designed materials must be obtained, not just pictures. Others are some actual debugging experience and actual design circuit diagrams, PCB issues to be considered, etc., such as the most stupid way to check power consumption, the supplier's board making process, etc. Oh, I also learned to do the production files of electronic BOM.
There must be problems with progress. First of all, the first one is that I am a bit irritable. I think the project is too smooth. When the problem is difficult to solve, I have no patience, and I will have a negative attitude. I realized this problem in the second half of the month, and it was very serious, so I slowly corrected it, and now it seems to be working. The second is that the courage is a bit small. How can I say this? In fact, I still think that I have too little work time. As an intern for more than two months (actual time to go to work in the company, the impact of the epidemic stopped for almost two months), the intern signed the company's project or participated in the actual project alone (the project has orders Product), I think it is stressful, because it is a newcomer, in fact, a lot of process things do not understand. When there is a problem, you will feel the pressure from the boss and the boss. At this time, if you ca n’t carry it, you will have negative emotions. For example, I will be afraid of losing money. Then I will think about other things, such as I put the golden finger. That night, I was really scared to death. I don't know if other interns will have this kind of situation, you can comment, ha ha ha ha ha. I still have to strengthen the pressure resistance.
