I. Product introduction
WTO-V8000 LED solid crystal solder paste, using flux with good wettability and solderability, and high sphericity, low oxygen content of Sn, Ag, Cu and Other trace rare metal alloy powders are scientifically formulated for the characteristics of the LED eutectic soldering process. The product has excellent thermal conductivity, mechanical properties, and low void ratio. It is suitable for the assembly process of LED chips and the soldering of flip-chip process. It is the ideal environmentally-friendly solid crystal solder paste for LED solid crystal soldering process.
Alloy composition: Sn96.5Ag3.0Cu0.5
Powder particle size: very fine powder
Second, product features
1, high thermal conductivity
Excellent thermal conductivity and electrical conductivity. The thermal conductivity of the alloy of this product is >50W/M•K, the void ratio after welding is less than 3%, which can greatly improve the thermal conductivity of LED products and improve the life of products.
2, high mechanical strength
The eutectic soldering strength is 5 times that of the original silver paste, and there is no problem that the silver paste is vulcanized and blackened after a long period of work.
Low residue: It adopts ultra-low residue formula, no need to clean after welding, and does not affect LED luminous efficiency.
3, process adaptability
Curing can be applied to reflow curing, heating plate curing, infrared heat curing process.
The viscosity is suitable for the dispensing process and the solder paste printing process.
It is made of ultra-fine powder and can meet the welding of small, medium and high power chips of 15mil and above.
4, low cost
The cost is lower than the thermal conductivity of 25W/M• K silver paste, but the performance is much higher than the silver adhesive bonding process, which can improve the life of the LED, high luminous efficiency and reduce light decay.
WTO-V8000 LED solid crystal solder paste is suitable for all small, medium and high power LED lamp bead packages with solderable metal, such as plating: Au, Cu, Ni , Ag and other solderable metal layers.
LED lamp beads packaged with WTO-V8000 LED solid crystal solder paste require low temperature or medium temperature solder paste for reflow soldering in subsequent processing.
Four, package specifications
Standard packaging: syringe packaging, 10g / support, 30g / support, 100g / support, can also be packaged according to customer needs.
5. Storage conditions
Solder paste sealed for a shelf life of 3 months (from the date of manufacture). Storage temperature: 2-10 ° C
The product is suitable for the dispenser, the solid crystal machine, and the process is the same as the silver glue process; the appropriate needle can be selected according to the chip size and the dispensing speed and the appropriate air pressure can be adjusted; The product can also be used in the printing process commonly used for solder paste, and the special steel mesh printing efficiency is higher.
The solder paste should be taken out of the freezer before use and thawed at room temperature. In order to achieve complete heat balance, it is recommended to return the temperature for at least 1 hour. After returning to temperature, be sure to avoid water droplets immersed in the solder paste before use. Otherwise, the characteristics of the solder paste will be affected.
Do not use used solder paste in the same container as unused solder paste. After the solder paste is opened, if there is still solder paste remaining in the syringe, it should not be placed in the air. The lid should be tightened as soon as possible and refrigerated as required.
Special diluents can be added in appropriate portions to change the viscosity to suit the customer's usage habits. Note: It needs to be stirred evenly before use.
Seven, eutectic soldering process and process
1, solder paste, sticky crystal
If a dispensing process is used, the solder paste, die bonding, and the like are the same as the conventional dispensing process.
If you use the solder paste printing process, you need to make a suitable steel mesh according to the size of the pad. You can consult our professional process engineers.
2, eutectic soldering
Set the temperature of the soldering furnace or the heating plate according to the recommended parameters, and then place the bracket of the solid chip on the reflow oven or the desktop heating plate, so that the metal plating on the bottom of the LED chip and the support base can be eutectic soldered through the solder paste. .
Furnace temperature setting for reflow soldering: Recommended parameters for each temperature zone of the reflow furnace can be consulted with our professional process engineers:
Chain speed: 90-130cm/min
The box type is thermostatically cured, and the curing time is about 1-3 minutes according to the actual welding conditions.
The recommended reflow profile is shown in the drawing. The recommended curve is the measured temperature of the product. There are differences in the performance of different brands of reflow ovens. The set temperature will be about 15-30 °C higher than the actual temperature. The soldered product does not need to be cleaned.
The crystal paste needs to be sealed and stored at 2-10 ° C, and the shelf life is 3 months.
Do not mix water and other substances in the solder paste. The working environment and the tools and materials that come into contact with the solder paste should be kept clean and dry. Otherwise, the solder paste may be cured.
After the solder paste is opened, it should be used up within 3 days. Do not expose the solder paste to the air for a long time. The solder paste left after use should be placed in a separate container and should not be mixed with fresh solder paste.
See the MSDS documentation for additional precautions.