Electronic Design - Design LED package at PCB board level

Designing LED packages at the PCB board level has always been a consideration for PCB factories.

Problems in the application of semiconductor lighting: heat dissipation; electrical design of semiconductor lighting is very different from traditional lighting. Traditional lighting companies need experience/skills accumulation process; there are price and design quality issues, and the final consumer chooses LED lighting and lacks confidence ; Lack of standards and uneven products.

Output drive voltage selection: most of the off-line lighting is 12V and 24V voltage; about 48V is more suitable for mains driving within 20W; the output voltage of larger power mains driving is about 36V.

Features: Consider the appropriatedrive voltage value of the load based on the safety of series and parallel connections, and try to unify the voltage value to reduce the cost of power supply design specifications; from the perspective of solving large-scale technology and quality problems in the LED lighting market; based on safety regulations, product design needs Meet the certification requirements, the current peak value exceeds 42.4Vac or the DC voltage exceeds 60Vdc.

When the output voltage is about 48V, the constant current efficiency of the low dropout linear constant current device is as high as 99%, and the constant current accuracy is within ±3%, which is not affected by any peripheral devices; when the output voltage is about 36V, the low dropout linear constant current device The constant current efficiency is as high as 98.6%, and the constant current accuracy is within ±3%, which is not affected by any peripheral devices; even in the offline lighting part, the lower voltage of 12V and 24V has 96% and 98% efficiency respectively; power size The efficiency is equal.

The combination design of the modules can effectively reduce the cost of one-time packaging; the scattered packaging forms are conducive to reducing the cost of heat dissipation design; the choice of domestic aluminum-based PCB plates; facilitates optical design; simplified power supply design; diverse packaging forms; beneficial to enhance domestic LED competition force.

Designing LED packaging at the PCB board level is easy and low-cost; everyone can brainstorm and develop different types of packaging; design products on the basis of power LEDs that integrate constant current technology and light distribution parameters; effectively cope with the ever-changing and ever-changing LED lamps need; the power supply part only uses the existing traditional switching constant voltage power supply; the product launch speed is increased, the lamp design is simple and practical, and the cost is greatly reduced; it can also avoid the frontier LED packaging patents.

Modular light source advantages: reduced thermal resistance; the light source is directly combined with the shell radiator; the heat dissipation path from the chip to the shell is reduced; the new heat transfer technology is adopted; the most effective reduction of heat dissipation thermal resistance, solves the problem of heat dissipation design; avoids PCB as Thermal medium. Modular light source advantages: high constant current accuracy; unified consideration of Vf value in the module; constant current source is affected by the outside world.