LED injection molding moduleCREE lamp beads detailed characteristics and authenticity (false) The following pass Q&A to answer customer concerns.

Q: Does Cree produce red light LED injection modulesCREE lamp beads?

A: Cree has never produced red LED injection molding modulesCREE lamps Bead chip, only blue light, green light and ultraviolet light LED injection molding module CREE lamp bead chip.

Q: Are all Cree chips made of silicon carbide (SiC) substrates?

A: At present, Cree's low-power LED injection molding module CREE lamp bead chips all use silicon carbide (SiC) material as the substrate, while EZBright series LED injection molding module CREE lamp bead chips use Si substrate structure. Cree is one of the few companies in the world that uses silicon carbide (SiC) as a substrate to produce blue, green and ultraviolet LED chips.

Q: Does Cree have chips with two-electrode structure?

A: Cree has launched a dual-electrode structure chip (ETC series) using silicon carbide (SiC) material as the substrate. The models are TR260, TR2432, TR2436, etc., mainly based on insulating glue. For details, please refer to Cree's product specifications Book.

Q: How is Cree's chip anti-static capability (ESD)?

A: The antistatic ability of all Cree LED injection molding module CREE lamp bead series chips using silicon carbide material as the substrate is greater than 1000V (HBM), and it is 100% tested.

Q: Can the electrostatic breakdown phenomenon of the CREE lamp bead chip of the LED injection molding module be observed through a low magnification microscope?

A: Usually, serious electrostatic breakdown can be observed by low magnification microscope with black holes on the surface of the chip. Slight electrostatic breakdown needs to be determined by high magnification microscope or SEM.

Q: What are the requirements for the amount of silver paste for Cree's LED injection module CREE lamp bead injection module CREE lamp bead chip during die bonding? What are the consequences of having too much or too little silver paste?

A: Cree recommends that the amount of silver paste during die bonding should be 1/3 of the height of the chip, and should not exceed 1/2 of the height of the chip, and the chip is surrounded by silver paste, Too much silver paste will block the light from the side of the chip, resulting in a decrease in the brightness of the finished product. If the silver paste overflows to the surface of the chip, it may cause a short circuit or even a dead lamp. If the silver paste is too small, it may cause poor contact, increased VF value of the finished lamp or dead lamp, etc. In addition, the deterioration of the silver paste may also cause the above problems. Appear.

Q: The brightness of Cree's LED injection module CREE lamp bead chip is usually expressed in mw. How to convert between mw and mcd?

A: The brightness of the Cree chip is generally expressed by the radiant power RF (Radiant Flux), and the unit is mw. It represents the light energy emitted by a light source per unit time, which is related to the customer's measuring equipment system. The candela (cd) refers to the luminous flux per unit solid angle, and has a great relationship with the shape of the package (lens shape). Both are defined and measured differently, so there is no conversion between mw and mcd.

Q: Why does the chip sorted by 20mA appear uneven in brightness and color when used at a current of 5mA?

A: There are several reasons for this phenomenon:

1. The brightness and wavelength of the CREE lamp bead chip of the LED injection molding module will change with the change of the current, and the change is non-linear; for green light, its wavelength drift is larger than that of blue light.

2. The CREE lamp bead chips of the LED injection molding module are sorted under the condition of 20mA constant current. If they work in parallel under the constant voltage source, the current distribution is uneven due to the different VF values of each chip, resulting in the appearance of wavelength and brightness. big difference. Please refer to Cree's product specification for the changing curve of the relationship between brightness, wavelength and current.

Q: What will happen if the optical axis of the chip center is not aligned with the geometric center of the bracket?

A: In this case, the finished product will have inconsistent light intensity, reduced radiation power, and asymmetric lighting.

Q: Can we identify the CREE chip by ourselves?

A: At present, there are more and more types of LED chips from CREE Company, and they have launched dual-electrode chips, so it is recommended that customers send them to our company for appraisal.

Q:   What is the effect of scratches on the surface of EZBright series chips?

A: The light-emitting layer on the surface of CREE EZBright series chips is a microcrystalline structure and lacks a protective layer. If the chip surface is accidentally scratched, it will damage the light-emitting layer of the chip, affect the light-emitting efficiency, and cause leakage in severe cases.