6-7 Operation Manual for Flux
6-7-1 Preparation：
1. Circuit boards and components: In order to maintain a stable welding performance and electrical reliability, circuit boards and components shall meet the solder-ability requirements and ion pollution requirements. Assembly manufacturers are suggested to establish the relevant provisions based on the requirements mentioned above and suppliers may be required to provide analysis reports or incoming inspection.
2. Pick-and-place: It is recommended that wearing clean non-woven gloves when picking or placing circuit boards. Please be cautious when contact the circuit boards; only the edge can be touched.
3. Cleaning: Conveyor belt, fixtures and trays should be kept clean and can be cleaned with detergent. In the replacement of a flux, it is recommended to use the new foam tubes (have a clean-off).
6-7-2 Application：
1. For the foam, the foam compressed air devices should be free of water and oil, and maintain full flux, which should be maintained 2 ~ 3cm higher than the foam pipe. Adjust the air pressure to get the best foaming height and foam fineness, and to make it foam at a constant rate to the top.
2. For the spray, the uniformity can be estimated with a piece of board (cardboard, glass, etc.) through the spray and preheat areas.
3. Solid content control: When used in foam, the diluent should be added to supplement the volatile solvents, to control the flux of the solid content. In continuous production, check whether proportion of solid content is in acceptable range every 2-4 hours.
4. Residues and contaminants will accumulate in the repeated use of the flux in long term use. In order to obtain good welding results, replacing
flux every one or two days is recommended, as well as cleaning the diluent tank and foam tubes.
5. The removal of residues: residue remains after soldering; it can be cleaned with special detergent if necessary.
6-7-3 Equipment setting：
| Operating parameters |
Reference value |
|
Coating volume |
foam：1000-1800 ug/cm2
spray：800-1500 ug/cm2 |
|
used in foam |
— |
|
Foam aperture |
20-50um |
|
Foam tube from the top to the surface flux |
20-30mm |
|
Foam pipe cover openings |
10-13mm |
|
Preheating temperature |
— |
|
Board surface |
80-110℃ |
|
Plate under the surface |
35℃ |
|
On-board increase in maximum speed of the surface (the original device in order to avoid injury) |
2℃/3.5° F/s |
|
Angle conveyors |
5-8° (6°) |
|
Conveyor speed |
1.1-1.8m/min |
|
Tin furnace slurry contact time |
1.5-3.5min |
|
Tin furnace temperature |
Sn63 |
235-265℃ |
|
lead-free |
258-270℃ |
Note: These are general guidelines and can lead to a good welding performance. However, different equipment, components and circuit boards will require different optimized settings, which require the pilot trials to determine the most important parameters (such as the volume of coating, conveyor speed, tin furnace temperature, preheating temperature).
6-7-4 Cautions：
1.In filtration and the welding process, avoid direct contact with skin and inhalation of steam. Better wear protective glasses and rubber gloves, masks in operation. If the any object splashes into the eyes in the process, wash the eyes immediately with plenty of water and seek for medical treatment afterwards.
2.Fetch the corresponding dose of flux according to the amount of output. Cap the flux liquid container if it’s not being used to protect it for future use; The color of flux may darken after long-time storage, which has no side effect for use.
3.Keep good ventilation in workshop or at the operation scene.
4.Operation must not be performed in haste. Be cautious in leaching flux and soldering process, in order to avoid flux splashing or hot liquid spattering.
6-7-5 Fire Contral Related Parameters
| Flash Point(°F):65 |
Auto Ignition Temperature:460℃ |
| Uel Upper(VOL):7.99 |
Usual Fire Explosion Hazards:N/O |
| Lel loower(VOL):2.02 |
Extinguisher Media:CO2/Powder Extinguisher |
