In the LED packaging process, the vulcanization mainly occurs in the solid crystal and dispensing packaging processes. The vulcanization mainly occurs in the materials containing silver (silver plated bracket and conductive silver glue) and silicone rubber materials. When silver containing materials are vulcanized, black silver sulfide will be generated, resulting in yellowing and blackening of the vulcanized area; Vulcanization of silicone rubber material will cause "poisoning" of silica gel, which will hinder curing and prevent complete curing. Poisoning of silicone curing agent: the silicone curing agent for LED packaging contains platinum (Platinum) complex, which is very easy to be poisoned. The toxic agent is any compound containing nitrogen (n), phosphorus (P) and sulfur (s). Once the curing agent is poisoned, the organic silicon is not cured completely, which will cause high linear expansion coefficient and increased stress.

For example, in the chip lamp bead packaging process, the materials that may be vulcanized during the production process include:

1. in the crystal fixing process, the silver plated bracket is vulcanized, and the bracket turns yellow and black and loses luster, which will reduce the reliability;

2. in the solidification process, the silver rubber is vulcanized, the silver rubber is black and the color is dim, which will lead to reliability reduction or failure;

3. in the solidification process, the silicon based solid crystal adhesive is vulcanized, which will hinder the curing and cannot be fully cured, resulting in the decrease or failure of the adhesion;

4. dispensing, powder dispensing and packaging processes. The vulcanization of silicon particle powder will hinder the curing, prevent complete curing, and make the product invalid;

5. in the powder dispensing process, the phosphor contains sulfur, which will hinder the curing and invalidate the product.

Preventive methods

1. the LED shall not be exposed to the workshop environment with partial acidity (ph<7). The nitrogen-containing acid gas will react with silver first, and then with sulfur / chlorine / bromine to produce black silver sulfide, silver chloride or silver bromide.

2. for other LED supporting materials purchased, the manufacturer can be required to provide the sulfur / bromine / chlorine removal test report of LED auxiliary materials provided by Jinjian to confirm whether there are sulfur, halogen and other substances in them, so as to prevent them from chemical or physical reaction with LED materials, resulting in silver plating corrosion of LED products, variation of LED silica gel and phosphor material performance, resulting in failure of LED photoelectric performance.

3. use desulfurization gloves, finger covers and sulfur free masks; Distinguish sulfur free materials and box clamp fixtures; Use sulfur free detergent; Sulfur containing PCB can be used after cleaning and desulfurization; Set up a special sulfur-free oven, use the products separately and bake independently.

4. substances prone to silica gel "poisoning" include: organic compounds such as N, P and S; Sn, Pb, Hg, Sb, Bi, as and other heavy metal ionic compounds; Organic compounds containing unsaturated groups such as ethynyl. Pay attention to the following materials:

1. organic rubber: sulfur vulcanized rubber such as gloves

2. epoxy resin and polyurethane resin: amine and isocyanate curing agent

3. comprehensive silicone RTV rubber: especially Sn catalyst

4. soft cyanoethylene: plasticizer and stabilizer

5. flux

6. Engineering Plastics: flame retardant, heat-resistant reinforcing agent, ultraviolet absorber, etc

7. silver plated and gold plated surfaces (the electroplating solution during manufacturing is the main reason)

8. Degassing produced by solver register (caused by heating and curing of silicone)

In the LED packaging process, the vulcanization mainly occurs in the solid crystal and dispensing packaging processes. The vulcanization mainly occurs in the materials containing silver (silver plated bracket and conductive silver glue) and silicone rubber materials. When silver containing materials are vulcanized, black silver sulfide will be generated, resulting in yellowing and blackening of the vulcanized area; Vulcanization of silicone rubber material will cause "poisoning" of silica gel, which will hinder curing and prevent complete curing. Poisoning of silicone curing agent: the silicone curing agent for LED packaging contains platinum (Platinum) complex, which is very easy to be poisoned. The toxic agent is any compound containing nitrogen (n), phosphorus (P) and sulfur (s). Once the curing agent is poisoned, the organic silicon is not cured completely, which will cause high linear expansion coefficient and increased stress.

For example, in the chip lamp bead packaging process, the materials that may be vulcanized during the production process include:

1. in the crystal fixing process, the silver plated bracket is vulcanized, and the bracket turns yellow and black and loses luster, which will reduce the reliability;

2. in the solidification process, the silver rubber is vulcanized, the silver rubber is black and the color is dim, which will lead to reliability reduction or failure;

3. in the solidification process, the silicon based solid crystal adhesive is vulcanized, which will hinder the curing and cannot be fully cured, resulting in the decrease or failure of the adhesion;

4. dispensing, powder dispensing and packaging processes. The vulcanization of silicon particle powder will hinder the curing, prevent complete curing, and make the product invalid;

5. in the powder dispensing process, the phosphor contains sulfur, which will hinder the curing and invalidate the product.

Preventive methods

1. the LED shall not be exposed to the workshop environment with partial acidity (ph<7). The nitrogen-containing acid gas will react with silver first, and then with sulfur / chlorine / bromine to produce black silver sulfide, silver chloride or silver bromide.

2. for other LED supporting materials purchased, the manufacturer can be required to provide the sulfur / bromine / chlorine removal test report of LED auxiliary materials provided by Jinjian to confirm whether there are sulfur, halogen and other substances in them, so as to prevent them from chemical or physical reaction with LED materials, resulting in silver plating corrosion of LED products, variation of LED silica gel and phosphor material performance, resulting in failure of LED photoelectric performance.

3. use desulfurization gloves, finger covers and sulfur free masks; Distinguish sulfur free materials and box clamp fixtures; Use sulfur free detergent; Sulfur containing PCB can be used after cleaning and desulfurization; Set up a special sulfur-free oven, use the products separately and bake independently.

4. substances prone to silica gel "poisoning" include: organic compounds such as N, P and S; Sn, Pb, Hg, Sb, Bi, as and other heavy metal ionic compounds; Organic compounds containing unsaturated groups such as ethynyl. Pay attention to the following materials:

1. organic rubber: sulfur vulcanized rubber such as gloves

2. epoxy resin and polyurethane resin: amine and isocyanate curing agent

3. comprehensive silicone RTV rubber: especially Sn catalyst

4. soft cyanoethylene: plasticizer and stabilizer

5. flux

6. Engineering Plastics: flame retardant, heat-resistant reinforcing agent, ultraviolet absorber, etc

7. silver plated and gold plated surfaces (the electroplating solution during manufacturing is the main reason)

8. Degassing produced by solver register (caused by heating and curing of silicone)

In the LED packaging process, the vulcanization mainly occurs in the solid crystal and dispensing packaging processes. The vulcanization mainly occurs in the materials containing silver (silver plated bracket and conductive silver glue) and silicone rubber materials. When silver containing materials are vulcanized, black silver sulfide will be generated, resulting in yellowing and blackening of the vulcanized area; Vulcanization of silicone rubber material will cause "poisoning" of silica gel, which will hinder curing and prevent complete curing. Poisoning of silicone curing agent: the silicone curing agent for LED packaging contains platinum (Platinum) complex, which is very easy to be poisoned. The toxic agent is any compound containing nitrogen (n), phosphorus (P) and sulfur (s). Once the curing agent is poisoned, the organic silicon is not cured completely, which will cause high linear expansion coefficient and increased stress.

For example, in the chip lamp bead packaging process, the materials that may be vulcanized during the production process include:

1. in the crystal fixing process, the silver plated bracket is vulcanized, and the bracket turns yellow and black and loses luster, which will reduce the reliability;

2. in the solidification process, the silver rubber is vulcanized, the silver rubber is black and the color is dim, which will lead to reliability reduction or failure;

3. in the solidification process, the silicon based solid crystal adhesive is vulcanized, which will hinder the curing and cannot be fully cured, resulting in the decrease or failure of the adhesion;

4. dispensing, powder dispensing and packaging processes. The vulcanization of silicon particle powder will hinder the curing, prevent complete curing, and make the product invalid;

5. in the powder dispensing process, the phosphor contains sulfur, which will hinder the curing and invalidate the product.

Preventive methods

1. the LED shall not be exposed to the workshop environment with partial acidity (ph<7). The nitrogen-containing acid gas will react with silver first, and then with sulfur / chlorine / bromine to produce black silver sulfide, silver chloride or silver bromide.

2. for other LED supporting materials purchased, the manufacturer can be required to provide the sulfur / bromine / chlorine removal test report of LED auxiliary materials provided by Jinjian to confirm whether there are sulfur, halogen and other substances in them, so as to prevent them from chemical or physical reaction with LED materials, resulting in silver plating corrosion of LED products, variation of LED silica gel and phosphor material performance, resulting in failure of LED photoelectric performance.

3. use desulfurization gloves, finger covers and sulfur free masks; Distinguish sulfur free materials and box clamp fixtures; Use sulfur free detergent; Sulfur containing PCB can be used after cleaning and desulfurization; Set up a special sulfur-free oven, use the products separately and bake independently.

4. substances prone to silica gel "poisoning" include: organic compounds such as N, P and S; Sn, Pb, Hg, Sb, Bi, as and other heavy metal ionic compounds; Organic compounds containing unsaturated groups such as ethynyl. Pay attention to the following materials:

1. organic rubber: sulfur vulcanized rubber such as gloves

2. epoxy resin and polyurethane resin: amine and isocyanate curing agent

3. comprehensive silicone RTV rubber: especially Sn catalyst

4. soft cyanoethylene: plasticizer and stabilizer

5. flux

6. Engineering Plastics: flame retardant, heat-resistant reinforcing agent, ultraviolet absorber, etc

7. silver plated and gold plated surfaces (the electroplating solution during manufacturing is the main reason)

8. Degassing produced by solver register (caused by heating and curing of silicone)