After the final product inspection is OK, the PCB boardis vacuum-packed and stored for shipment. So why do PCB boards need vacuum packaging? How to store after vacuum packing? And how long does it last? The following circuit board factory will give you a brief introduction to the storage of PCB board and its shelf life.
Why do PCB boards need vacuum packaging? This problem is small, but it is a lot of circuit board manufacturers attach great importance to the problem. Because once the PCB board is not sealed well, its surface gold, tin spray and solder plate parts will be oxidized and affect welding, not conducive to production.
So, how to store PCB board? The circuit board is not like other products, it can not contact with air and water. First of all, the vacuum of PCB board can not be damaged. When packing, a layer of bubble film needs to be wrapped around the side of the box. The water absorption of bubble film is better, which plays a good role in moisture-proof. Then classify the emissions and label them. After sealing the box must be separated from the wall, stored away from the ground in a dry ventilated place, but also avoid sunlight. The temperature of the warehouse is best controlled at 23±3℃, 55±10%RH, under such conditions, the surface treatment of gold, electric gold, tin spray, silver plating PCB board can be stored for 6 months, the surface treatment of silver, tin, OSP PCB board can be stored for 3 months.
For the PCB board that is not used for a long time, the circuit board manufacturer had better brush a layer of three anti-paint on it. The role of three anti-paint can be moisture-proof, dustproof and anti-oxidation. This will increase the PCB board storage life to 9 months
Circuit board manufacturer -- What's the most moving thing dad ever said to you?
Section generally to low-key many, today let Shenzhen circuit board factory small make up to take stock of usually silent pragmatic fathers have said to you what let you cry?
Shenzhen circuit board factory Xiaobian is a girl, so the most resonant to this sentence:
"If you really like someone who doesn't have any money, we have to help you."
Your voice: Although you set a lot of rules for your partner, when it comes to true love, all the fear and resentment will turn into protection and support.
Boys, has dad ever stared at you silently for a long time, and then said
'You are just like me when I was young'
Voice: He considers you his greatest work, and it's hard not to be impressed by your similar faces and life paths.
When you were having trouble at school or at work, did your dad ever say to you with guilt,
"You might think that Dad doesn't have the skills to be somebody else's dad."
Voice: Don't complain that what your parents give is not good enough. It may be all they can give.
Has your old man ever said anything kinder to you? Welcome to leave a message to Shenzhen circuit Board factory!
Test method for uniformity of temperature and pressure of multilayer PCB presses
In the process of multilayer PCB processing, it is essential to use the pressing machine, and the uniformity of pressure and temperature of the pressing machine has a great influence on the quality of the pressing. How to test its stability regularly through the way of testing, so as to ensure the quality of the product. There is a discussion on this issue in the forum, and the results of the discussion are summarized as follows:
1, pressure uniformity test method:
For the pressure uniformity test, there is a special induction paper, the effect of the old high copy paper, better, but very expensive. In addition, standard lead strips can be arranged in the press test, after the end of measuring the residual thickness of each section of the lead strips can also know the uniformity of the press, and the value can be quantified.
2. Test method of temperature uniformity:
The thermocouple thermometer is used to make several thermocouple lines, and then according to the position of the platform, the nine points or more points are placed, and the temperature data of each position is recorded after pressure, and then the statistical data is made into a chart form, which can be intuitive and convenient to see the temperature uniformity of the whole pressing platform. At the same time, the temperature reproducibility can be obtained through multiple tests, so as to systematically evaluate the performance of the press.