The basic knowledge of LED patch adhesive

The basic knowledge of LED patch adhesive

1, the role of LED patch glue

Surface mount adhesives (SMA, surface mount adhesives) are used for wave soldering and reflow soldering. They are mainly used to fix components on printed boards, usually by dispensing or stencil printing. Keep the component in place on the printed circuit board (PCB), ensuring that components are not lost during transport on the assembly line. After attaching the components, put them in an oven or reflow soldering machine to heat harden. It is different from the so-called solder paste. Once it is hardened by heat, it will not melt even if it is heated. That is to say, the thermal hardening process of the patch glue is irreversible. The use of SMT patch adhesives varies depending on the heat curing conditions, the connected materials, the equipment used, and the operating environment. When using, choose the patch glue according to the production process.

2, LED patch adhesive ingredients

Most surface mount adhesives (SMA) used in PCB assembly are epoxies, although polypropylene is also used for special applications. After the introduction of high-speed dispensing systems and the electronics industry's understanding of how to handle products with relatively short shelf life, epoxy resins have become the more mainstream glue technology worldwide. Epoxy resins generally provide good adhesion to a wide range of boards and have very good electrical properties. The main ingredients are: base material (ie, high molecular weight material), filler, curing agent, other additives.

3, the purpose of the use of LED patch glue

a. Prevent the components from falling off during wave soldering (wave soldering process)

b. Prevent the other components from falling off during reflow soldering (double-sided reflow soldering process)

c. Prevent component displacement and standing (reflow process, pre-coating process)

d. Marking (wave soldering, reflow soldering, pre-coating), when the printed boards and components are changed in batches, they are marked with patch glue.

4, LED patch adhesive use classification

a. Dispensing type: sizing on a printed circuit board by means of a dispensing device.

b. Squeegee type: sizing by stenciling or copper mesh printing.