1. The role of a plastic patch LED Lights
SMA, surface mount adhesives, for wave soldering and reflow soldering, and is mainly used to components on the printed circuit board, the general dispensing or stencil printing method to allocate in order to maintain the components in printed circuit position on the board (PCB), to ensure that components are not lost in the transmission process on the assembly line. Paste components into the oven or welder heating reflow sclerosis. With the so-called solder paste is not the same, after a heated hardening, and then heating it will not melt, thermosetting plastic patch process is not reversible. The use of SMT chip (super bright led headlamp) adhesive effect due to the thermal curing conditions, the connecting object, the equipment used, the operating environment differ. When used according to the production process to choose a plastic patch.
2, the composition of the plastic patch LED STREET LIGHT
PCB assembly used in the majority of surface mount adhesive (SMA) are epoxy resin (epoxies), although there are polypropylene (acrylics) for special applications. After high-speed dispensing system into the electronics industry to learn how to deal with a relatively short shelf life products, epoxy resins has become more mainstream glue technology worldwide. Epoxy resins generally provide a good adhesion on a wide range of circuit board, and has very good electrical properties. The main ingredients: the base material (ie, the main high molecular material), fillers, curing agents, other additives such as.
3, the intended use of the adhesive patch LED TUBES
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.
4, 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 (super bright led headlamp) or copper mesh coated scratch sizing.
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 (super bright led headlamp) may be damaged.