9.1 Group III Nitride LED Packaging Materials
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such as high temperature welding resistance, high reflection, and combination with
silica gel and reliability. On the other hand, high power lead frame is generally plastic
reflector cup and rivet type heat dissipation structure.
9.1.3 LED Die Bonding Glue
There are two main types of glue for LED die bonding [3–5]: conductive silver
glue and insulating glue. The conductive silver paste is mainly composed of a resin
matrix, conductive particles, and a dispersion additive. It is an adhesive with certain
conductivity after curing or drying. It can be cured at room temperature to 150 °C,
which is much lower than that of the tin–lead soldering. This would prevent material
deformation caused by high soldering temperature, thermal damage of electronic
devices and the formation of internal stress. The requirements of the conductive
silver paste are good electrical conductivity, good thermal conductivity, high shear
strength, and strong adhesion. As far as insulating paste is concerned, insulating
rubber is mainly used for heat dissipation and fixing of chips. The composition is
mostly resin.
The application procedure and process of silver glue and insulating glue are very
different. For example, silver glue needs to be stirred, the insulation glue does not
need to be stirred; silver glue has good heat dissipation, and the insulation rubber
has poor heat dissipation; and silver glue has stronger light absorption and weaker
reflectivity. Therefore, the brightness of silver glue in LED products is lower than
that of insulating glue.
9.1.4 Bonding Wire
In the LED packaging, two electrodes of the chip and the LED lead frame need
to be connected by bonding wires so that electricity can be injected into the LED
chip. LED bonding alloy wire is widely used in various packaging occasions since
it has the advantages of high electrical conductivity, oxidation resistance, corrosion
resistance, good toughness, etc. The alloy wire is mainly made of Au with a purity
of more than 99.99%, which contains trace elements such as Ag/Cu/Si/Ca/Mg [6].
In addition, the diameter of the alloy wires on the market is in the range of 16 um to
50 um according to the requirement of applications.
9.1.5 LED Packaging Adhesive
There are two main types of LED package adhesives: epoxy resin and silica gel.
Epoxy resin generally refers to an organic polymer compound having two or more
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such as high temperature welding resistance, high reflection, and combination with
silica gel and reliability. On the other hand, high power lead frame is generally plastic
reflector cup and rivet type heat dissipation structure.
9.1.3 LED Die Bonding Glue
There are two main types of glue for LED die bonding [3–5]: conductive silver
glue and insulating glue. The conductive silver paste is mainly composed of a resin
matrix, conductive particles, and a dispersion additive. It is an adhesive with certain
conductivity after curing or drying. It can be cured at room temperature to 150 °C,
which is much lower than that of the tin–lead soldering. This would prevent material
deformation caused by high soldering temperature, thermal damage of electronic
devices and the formation of internal stress. The requirements of the conductive
silver paste are good electrical conductivity, good thermal conductivity, high shear
strength, and strong adhesion. As far as insulating paste is concerned, insulating
rubber is mainly used for heat dissipation and fixing of chips. The composition is
mostly resin.
The application procedure and process of silver glue and insulating glue are very
different. For example, silver glue needs to be stirred, the insulation glue does not
need to be stirred; silver glue has good heat dissipation, and the insulation rubber
has poor heat dissipation; and silver glue has stronger light absorption and weaker
reflectivity. Therefore, the brightness of silver glue in LED products is lower than
that of insulating glue.
9.1.4 Bonding Wire
In the LED packaging, two electrodes of the chip and the LED lead frame need
to be connected by bonding wires so that electricity can be injected into the LED
chip. LED bonding alloy wire is widely used in various packaging occasions since
it has the advantages of high electrical conductivity, oxidation resistance, corrosion
resistance, good toughness, etc. The alloy wire is mainly made of Au with a purity
of more than 99.99%, which contains trace elements such as Ag/Cu/Si/Ca/Mg [6].
In addition, the diameter of the alloy wires on the market is in the range of 16 um to
50 um according to the requirement of applications.
9.1.5 LED Packaging Adhesive
There are two main types of LED package adhesives: epoxy resin and silica gel.
Epoxy resin generally refers to an organic polymer compound having two or more