2024-01-19
The four causes and control methods of LED lamp strip producing tin beads
The four causes and control methods of LED lamp strip producing tin beads
Like other SMT products, LED strips also produce tin beads during the production process. The harm of tin beads is that after the user installs the LED light belt, the use of the process will cause short circuit and burn the LED light belt and cause fire hazards. How to prevent the occurrence of tin beads? Let's talk about the formation of tin beads.
1, the solder paste temperature return time is not enough: the solder paste generally needs to be heated for 4 hours before use to ensure that the solder paste can return to room temperature, to avoid moisture generated due to insufficient temperature return time, resulting in the LED light with the furnace when the water in the solder paste is heated and produced tin beads.
2, FPC moisture: FPC moisture will contain moisture and heat evaporation during the furnace, causing the molten solder to splash and form tin beads on the surface of the LED lamp strip.
3. Too much solder: too much solder on the pad of the LED lamp will overflow to the outside of the pad due to the extrusion of the LED during reflow and form tin beads.
4, improper temperature setting: the preheating time is too short, the reflux temperature rises too fast, causing the flux in the solder to be too late to volatilize and be heated out, causing the solder to splash and form tin beads on the surface of the LED lamp strip.
2, FPC moisture: FPC moisture will contain moisture and heat evaporation during the furnace, causing the molten solder to splash and form tin beads on the surface of the LED lamp strip.
3. Too much solder: too much solder on the pad of the LED lamp will overflow to the outside of the pad due to the extrusion of the LED during reflow and form tin beads.
4, improper temperature setting: the preheating time is too short, the reflux temperature rises too fast, causing the flux in the solder to be too late to volatilize and be heated out, causing the solder to splash and form tin beads on the surface of the LED lamp strip.
Understand the cause, and then talk about the solution.
1, the solder paste fully return temperature, develop the solder paste return temperature management system to ensure the return temperature time.
2. Bake the FPC. Bake the FPC in an oven at 80 degrees for 3 to 4 hours.
3, open steel mesh: according to the proportion of 95% of the opening, the thickness of 0.13~0.15mm
4, reflux temperature setting preheating temperature is controlled between 180~210, the time is controlled between 150~180, the welding temperature is set between 235~245, the time is controlled between 5~10 seconds.
2. Bake the FPC. Bake the FPC in an oven at 80 degrees for 3 to 4 hours.
3, open steel mesh: according to the proportion of 95% of the opening, the thickness of 0.13~0.15mm
4, reflux temperature setting preheating temperature is controlled between 180~210, the time is controlled between 150~180, the welding temperature is set between 235~245, the time is controlled between 5~10 seconds.
