Application scope:
It is a high fluidity, high-purity single component epoxy resin potting material. Innovative capillary action can be used to fill the bottom of CSP and BGA chips, forming a strong filling layer after heating and curing, reducing the stress impact caused by the difference in thermal expansion coefficient between the chip and the substrate, and improving the structural strength and reliability of the components.

Product features:
It has good fluidity at room temperature, small filling gaps, fast filling speed, and can quickly cure at lower heating temperatures. It is compatible with most lead-free and Wuxi solder pastes and can be repaired. It has excellent electrical and mechanical properties.

Why use bottom filling adhesive?

Bottom filling adhesive coating method:

Parameter performance:
Product model: VS-3220
Viscosity: 4000-5000 mPa. s
Tg： 148℃
Thermal expansion coefficient: 40-140 ppm/℃
Curing conditions: 10min@165 ℃
Storage temperature: -20

Usage method:
Install the product onto dispensing equipment, which is suitable for many types of dispensing equipment, including manual dispensing machines/time pressure valves, spiral valves, linear piston pumps, and spray valves. The selection of equipment should be based on the requirements of use.
During the device setup, ensure that no air is introduced into the product.
To achieve the best results, the substrate should be preheated (usually at 40 ℃ for about 20 seconds) to accelerate capillary flow and promote leveling.

3. Apply glue at a suitable speed (2.5-12.7mm/s). Ensure that the distance between the needle tip and the edges of the substrate and chip is 0.025-0.076mm, which ensures optimal flow of the bottom filling adhesive.
The usual way of applying glue is to follow an "I" shape along one edge or an "L" shape along two edges intersecting at the corner. The starting point of adhesive application should be as far away from the center of the chip as possible to ensure that there are no voids in the filling of the chip. When applying glue, the length of each glue in the "I" or "L" shape should not exceed 80% of the chip.
In some cases, a second or third application of glue may be necessary on the product.

Repair service:
1. Remove the CSP (BGA) from the PCB board, and any equipment that can melt is suitable for removing the CSP (BGA) in this step. When reaching the effective height (200-300 ℃), use a scraper to contact the bottom filling adhesive strip around the CPS (BGA) and PCB. If the adhesive strip is soft enough, remove the edge adhesive strip. When the temperature is equal to the melting temperature of the solder, and the solder flows out from the gap between the CSP (BGA) and the PCB, use a scraper to remove the CSP (BGA) from the PCB board.
2. Draw in air to remove the melted solder material from the bottom filling adhesive.
3. Remove the remaining bottom filling adhesive from the PCB board. After removing the CSP (BGA), use a soldering iron to scrape off the remaining bottom filling adhesive on the PCB board. The recommended soldering iron temperature is 250~300 ℃. Be careful when scraping to avoid damaging the solder pads on the PCB board.
4. Cleaning: Use a cotton swab dipped in a suitable solvent (acetone or specialized cleaning agent) to scrub the surface. Use a dry cotton swab to scrub again.

Matters needing attention:
During the transportation process, all transportation items require the placement of cold bags to maintain a temperature below 8 ℃.
2. The glue stored in refrigeration must be reheated before use, and a 30ml syringe requires 1-2 hours (the actual required time may vary depending on the size/volume of the packaging).
3. Do not open the mouth, lid, or cap of the packaging container. The packaging of the syringe tube must be placed under the mouth. Do not thaw by heating, as it may cause partial solidification of the adhesive.
To avoid contamination of unused adhesive, do not pour any adhesive back into the original packaging.


Product specifications:
30ml/tube
Storage conditions:
-Low temperature storage at 20 ℃