PCB Technical - PCB proofing storage PCB maintenance

Now it has become a high-paying industry, and many PCB proofings with good quality and low prices on the market have very wide applicability. Choosing a good quality PCB proofing is the ultimate goal of many consumers. However, I think that in addition to choosing a good quality PCB for proofing, the maintenance of the PCB at the end of the proofing is actually more important. But how to maintain PCB proofing?
PCB proofing maintenance one:
Regular cleaning: After long-term use, there will be some use residues and solder accumulation on the PCB proofing circuit board, which will bring unpredictable risks to the solder mask, and even these residues may directly lead to corrosion and corrosion of the soldering surface. Contamination risk, which may lead to reliability problems, such as defective solder joints or electrical failures, and increase the probability of failure of PCB proofing. Regular cleaning can effectively improve the reliability of PCB proofing in use.
PCB proofing and maintenance two:
Strictly control the service life of each surface treatment, and replace the PCB proofing surface processor on time: The most prone problems of electronic products will also appear on PCB proofing. If the service life of each surface treatment is not strictly controlled, PCB proofing may cause soldering problems due to metallographic changes in the surface treatment of the old PCB board, and if the service life is not paid attention to, it is easy to cause damage to the protective surface of the PCB proofing. This may cause moisture to enter, which may cause problems such as delamination and internal disconnection during the assembly process or actual use. However, if you pay attention to the service life of the surface treatment in the later period, you can effectively improve the solderability of PCB proofing and reduce the risk of moisture intrusion and harm to other internal systems.
PCB proofing maintenance three:
Use the designated brand and model of peelable blue glue for maintenance: using inferior and cheap peelable glue may blistering, melting, cracking or solidifying like concrete during the assembly of PCB proofing, so that the peelable glue will peel off Does not come down or has no effect.
The relationship between the size of the PCB proofing electroplating bath and the average loading capacity, cathode current density, volume current density, etc.;

PCB proofing Generally speaking, the size of the electroplating tank refers to the volume L of the electrolyte in the plating tank, also known as the effective volume, that is, the length of the inner cavity of the electroplating tank X the width of the inner cavity X the depth of the electrolyte;
PCB proofing can generally be calculated and matched according to the electroplating processing volume or the existing DC electroplating equipment and other conditions;
Choosing the appropriate size of the electroplating bath is of great significance for preparing production plans, estimating production capacity and ensuring the quality of electroplating;
Three considerations for determining the size of the electroplating tank:
1. Meet the size requirements of processed parts;
2. Prevent the electrolyte from overheating;
3. Able to maintain a certain stability of electrolyte components during the electroplating production cycle;
The current density of the cathode and anode is calculated based on the total area actually immersed in the electrolyte. There is a slight difference due to the difference in the current efficiency of the cathode and anode;
DA=I total/S Yin (A/dm2)
DA=I total/S Yang (A/dm2)
Average loading d: the volume of electrolyte needed for electroplating parts per unit area
is d=V/S(L/ dm2)
Volume current density DV:
The intensity of the current passing through the unit volume is: DV=Itotal/V(A/L)
PCB proofing and electroplating process is important to properly control the volume current density, because the current through the electrolyte will generate heat due to the resistance of the solution, causing the electrolysis temperature to rise, and the speed and height of the electrolyte heating are directly related to the volume current density. In order to prevent the electrolyte from heating up too quickly, a larger volume of electrolyte is necessary to reduce the volume current density;
Such as acidic bright copper plating process: The appropriate volume current density is 0.3-0.4A/L, that is, when the total current is 1000A, 2500-3000L electrolyte should be equipped;
Empirical data:
PCB proofing The following data is some empirical data related to the cathode current density and average loading of various common plating species:
Plating species Cathode current density range DK, A/ dm2 Average loading d, L/ dm2
Sulphate copper plating 1.0---3.0 7---9
Acid tin plating 1.0---3.0 7---9
Bright nickel 2.0---4.0 6---8
Nickel 1.0---1.5 6---8