A Guide to the Operation of Soldering Flux
I. Application of soldering flux
A guide to the operation of spray operation
1. Note the adjustment of nozzles when spraying operation. Make sure to enable the soldering flux to be well distributed on the PCB plate.
2. Adjust the volume of spray of soldering flux as the case may be:
Generally, the case where necessary increase in soldering flux includes:
(1) When substrates are severely oxidized (Such phenomenon cannot be distinguished by naked eyes, so it must be subject to the test ).
(2) When the part pins are severely oxidized (ditto).
(3) When the density of subs
trates is high.
(4) When the substrate part direction is not identical to that of the solder.
(5) Multi-layer plates.
(6) When the solder temperature is too low.
3. When it is required that the board surface should be clean, under the circumstances that solder effect is guaranteed, it is allowed to reduce the volume of soldering flux, but it is necessary to ensure that every corner of the PCB boards will be sprayed with soldering flux.
4. When soldering flux containing rosin is used for spray operation, it is advisable to perform shift operation using two nozzles to ensure that the nozzles will not be jammed or blocked.
A Guide to Foaming Operation
1. In the time of soldering flux foaming operation, the operation weight should be subject to the substrates or the oxidization of part pins. The weight of soldering flux should be controlled within 0.01 of the specification value. The weight of soldering flux changes as the temperature does. Generally it is based on the weight at 20℃. From the experience, within the range of the temperature (15-30℃), when the temperature rises by one degree centigrade, the weight of soldering flux will drop by 0.001. If the weight of a certain soldering flux is 0.820 at 20℃, and the weight at 30℃ will be 0.810. When it is the first time for use, it can start form the higher weight and adjust to the lower weight until it reaches the ideal pad.
2. Case where higher weights are set during operation include:It is the same as the case where the increase in the volume of soldering flux is necessary for spray operation
3.In daily operation, it is necessary to check the weight every two working hours. In the case of exceeding the set standard, justimmed iately add thinner to restore the originally set weight standards. Otherwise, when it is lower than the set standard, it is necessary to immediately add original soldering flux liquids to recover originally set weight standards.
4.When the foaming manners are used, please make regular overhaul and check of the pressure of the air compressors. It is advisable to be able to prepare for two courses of filters to prevent water vapors from entering the soldering flux, which will adversely affect the structure and performance of soldering flux
5.When it is in the foaming process, for the particles of foams, the tenser the better. It is necessary to note at any time whether the foam particles are well proportioned in size. Otherwise, there must be jams, leak of air or failures of the foaming tubes. The height of foaming should not exceed the substrate surface. But the foaming performance of soldering flux containing low solids will be somewhat poorer. We recommend spray operation for soldering flux with low solid content.
6.When the soldering flux in a foaming groove is out of use, please cover it immediately so as to prevent volatility or contamination with water vapors, or keep it in a clean container. If not passing the substrate solder, please do not let the soldering flux foam so as to reduce pollution of various kinds.
7.For the products demanding higher quality, the soldering flux must be all discharged after use for 24 hours so as to replace the same with new liquids, thus preventing pollution, ageing, which may affect the operation effect and quality.
8.The soldering flux may be used for long pin secondary operation. During soldering for the first time, try to perform low weight operation so as not to injure substrates and parts due to high temperature for the second time or to cause atomization of pads.
II. Setting Parameters
250±10℃（Sn63/Pb37）
Preheat temperature: 90-140℃ (lead free); 80-130℃ ( lead-containing)
Jig angle: 40-80 (generally 60)
Conveyance rate: 0.8-1.5m/min
Solder pot temperature: 260±10℃(lead free)
250±10℃(Sn63/Pb37）
III. Curve of Temperature
Curve of temperature for lead-free wave soldering
Peak value temperature 250-270℃
Preheating time
Temperature
Time
Curve of temperature for lead-free wave soldering
Peak value temperature 250-270℃
Preheating time
Temperature
Time
IV. Safety Cautions in Soldering Flux Operation
1. Soldering flux is a combustible chemical material. It requires operation under well ventilated operation conditions and keeps it away from fire.
2. The soldering flux should be kept at a cool and dark ventilated place away from fire sources and direct sunshine.
3. After being unsealed, the soldering flux should be kept after sealing. The used soldering flux should be poured into the original package to ensure the cleanliness of the original fluid.
4. The rejected soldering flux must be disposed of by specific personnel. It may not be dumped at random, which will cause pollution to environments.
5. If your hands and feet contact it, wash immediately with soap and clean water. If it contaminates your five organs, please rinse with soap and clean water.
Do not rub the affected parts by hands. Seek for medical assistance and advice as soon as possible.
