1. Selection of packaging materials

• Quartz glass (SiO₂) :

1. Advantages: high light transmittance, especially in UVC band (200-280nm), high temperature resistance, good chemical stability.
2. Disadvantages: high cost, difficult to process.

• High borosilicate glass:

1. Advantages: low cost, good light transmission, relatively easy processing.
2. Disadvantages: light transmittance is slightly lower than quartz glass, long-term use may be aging.

• Ceramic material:

1. Advantages: Good thermal conductivity, high temperature resistance, high mechanical strength.
2. Disadvantages: poor light transmission, usually used for bottom packaging.

2. Packaging structure anatomy

• Lens design:

1. Material: Commonly used quartz glass or high borosilicate glass.
2. Function: Focus and guide UVC light to improve light output efficiency.
3. Design: Lens shape (e.g. hemispherical, flat convex) affects light distribution and intensity.

• Sealant:

1. Material: commonly used silica gel or epoxy resin.
2. Function: Protect the chip from the environment (such as moisture, dust), improve durability.
3. Features: silicone high temperature resistance, anti-aging; Epoxy resin is low cost, but poor heat resistance.

• Reflector:

1. Material: Commonly used aluminum (Al) or silver (Ag).
2. Function: Reflect UVC light, improve light output efficiency.
3. Location: Usually located on the bottom or side of the package.
4. Heat dissipation structure:
5. Material: usually aluminum or copper.
6. Function: Heat dissipation, prevent chip overheating, prolong life.
7. Design: including heat sink, heat sink, etc., need to consider heat dissipation efficiency and space limitations.

3. Packaging process

• Chip fixing:

1. Method: The chip is fixed on the substrate with common solder or conductive adhesive.
2. Requirements: Ensure good electrical contact and heat dissipation.

• Lead bonding:

1. Material: Commonly used gold (Au) or aluminum (Al) wire.
2. Function: Connect the chip electrode to the external circuit.

• Sealing process:

1. Methods: Commonly used air-tight package to prevent moisture and oxygen from entering.
2. Process: such as vacuum package or nitrogen-filled package.

4. Optical and thermal design

• Optical design:

1. Light extraction efficiency: Improved light output through lens design and reflectors.
2. Light distribution: Lens shape and package structure affect light distribution and intensity.

• Thermal design:

1. Heat dissipation path: Ensures effective conduction of heat from the chip to the external heat sink.
2. Thermal interface materials: such as thermal glue or solder, reduce thermal resistance.