stealth led grow and surface mount adhesives

1, the led lights intended use of the adhesive patch
a wave soldering to prevent the components off (wave soldering)
b. reflow to prevent the other side of the components off (double-sided reflow soldering process)
c. to prevent the components of displacement and stand at (reflow soldering process, pre-coating process)
d mark (wave soldering, reflow soldering, pre-coating), printed boards and components, bulk changes, marked with plastic patch.

stealth led grow and surface mount adhesives
2, led street lights adhesive patch used classification
a dispensing type: on the printed circuit board through dispensing equipment in Sizing.
b Squeegee type: the printing of steel mesh or copper mesh coated scratch sizing.

3, Epoxy Method
SMA can be used syringe dispensing method, the needle transfer method or template printing method applied to the PCB. The use of needle transfer less than all of the application of 10%, it is the use of needles arranged in the array immersed in a plastic tray. And then hanging plastic drop transfer to the board as a whole. These systems require a lower viscosity of the adhesive, but also on the moisture absorption, good resistance, because of its exposure in the indoor environment. Control needle transfer Epoxy key factors including the temperature of the needle diameter and style, plastic, and the cycle length of the needle immersed in the depth and dispensing (including needle exposure to PCB before and during the delay time). Pool, tank temperature should be between 25 to 30 ° C, which controls the number and form of the plastic viscosity and gel point.

Template printing and led panel is widely used in solder paste can also be used with the allocation of glue. Although less than 2% of SMA using the template printing, but this method has been increased interest in new equipment is to overcome the earlier limitations. The template parameter is the key to achieve good results. For example, the contact printing (zero off-board height) may require a delay cycle, allows the formation of the gel-point. In addition, non-contact printing of polymer template (about 1 mm gap) requires the best squeegee speed and pressure. The thickness of the metal template for 0.15 ~ 2.00mm, should be slightly larger than the gap between the component and PCB (+0.05 mm).

The final temperature will affect the shape of viscosity and gel point, most modern dispensing machines rely on the needle mouth or chamber temperature control device to maintain temperature above room temperature of the plastic. However, if the PCB temperature increased from the preceding process, the outline of the gel-point may be damaged.