Composite film, encapsulating structure of the same, and encapsulation method

A light-emitting diode (LED) backlight module, comprising:

• a light-emitting diode (LED) unit, having at least one surface;
• and
• a composite film, disposed on and encapsulating the at least one surface of the LED unit, the composite film comprises:
• a first thermoplastic elastomer film layer, comprising a first styrenic block copolymer;
• and
• a second thermoplastic elastomer film layer, disposed on the first thermoplastic elastomer film layer, wherein the second thermoplastic elastomer film layer comprises a second styrenic block copolymer, a plurality of diffusion particles dispersed in the second thermoplastic elastomer film layer, and a surface microstructure disposed on a surface of the second thermoplastic elastomer film layer.

An encapsulation method of a light-emitting device, comprising:

• encapsulating a composite film on a surface of a substrate of a light-emitting diode (LED) unit by heat pressing, wherein the composite film comprises:
• a first thermoplastic elastomer film layer, comprising a first styrenic block copolymer, wherein the first thermoplastic elastomer film layer is in direct contact with the surface of the substrate;
• and
• a second thermoplastic elastomer film layer, disposed on the first thermoplastic elastomer film layer, wherein the second thermoplastic elastomer film layer comprises a second styrenic block copolymer, a plurality of diffusion particles dispersed in the second thermoplastic elastomer film layer, and a surface microstructure disposed on a surface of the second thermoplastic elastomer film layer.