LED aluminum substrate professional knowledge introduction

led的散热问题是LED厂家最头痛的问题，不过可以采用铝基板，因为铝的导热係数高，散热好，可以有效的将内部热量导出。铝基板是一种独特的金属基覆铜板，具有良好的导热性、电气绝缘性能和机械加工性能。设计时也要儘量将PCB靠近铝底座，从而减少灌封胶部分产生的热阻。

1. Characteristics of aluminum substrate

1. Using surface mount technology (SMT);

2. Effectively handle heat diffusion in circuit design;

3. Reduce product operating temperature, improve product power density and reliability, and extend product service life;

4. Reduce product size and reduce hardware and assembly costs;

5. Replace fragile ceramic substrates to achieve better mechanical durability.

2. Structure of Aluminum Substrate

Aluminum-based copper-clad laminate is a metal circuit board material, consisting of copper foil, thermal insulation layer and metal substrate. Its structure is divided into three layers:

Circuit layer: equivalent to the copper clad board of ordinary PCB, the circuit copper foil thickness is from 10oz to 10oz.

DiELcctricLayer insulation layer: The insulation layer is a layer of low thermal resistance thermal conductive insulation material.

BaseLayer: It is a metal substrate, usually aluminum or copper. Aluminum-based copper-clad laminates and traditional epoxy glass cloth laminates, etc.

The circuit layer (i.e. copper foil) is usually etched to form a printed circuit to connect the various components of the component to each other. In general, the circuit layer is required to have a large current-carrying capacity, so a thicker copper foil should be used, with a thickness of generally 35μm~280μm; the thermal conductive insulation layer is the core technology of the aluminum substrate. It is generally composed of a special polymer filled with special ceramics. It has low thermal resistance, excellent viscoelastic properties, resistance to thermal aging, and can withstand mechanical and thermal stress.

The thermal insulation layer of the high-performance aluminum substrate uses this technology, which makes it have extremely excellent thermal conductivity and high-strength electrical insulation performance; the metal base is the supporting component of the aluminum substrate, which is required to have high thermal conductivity. It is generally an aluminum plate, and a copper plate can also be used (copper plate can provide better thermal conductivity). It is suitable for conventional mechanical processing such as drilling, punching and cutting. Compared with other materials, PCB materials have incomparable advantages. It is suitable for surface mounting SMT technology of power components. No heat sink is required, the volume is greatly reduced, the heat dissipation effect is excellent, and the insulation and mechanical properties are good.

3. Application of aluminum substrate:

Application: Power Hybrid IC (HIC).

1. Audio equipment: input and output amplifiers, balanced amplifiers, audio amplifiers, preamplifiers, power amplifiers, etc.

2. Power supply equipment: switching regulator, DC/AC converter, SW regulator, etc.

3. Communication electronic equipment: high-frequency amplifier, filter device, and transmission circuit.

4. Office automation equipment: motor drivers, etc.

5. Automobile: electronic regulator, igniter, power controller, etc.

6. Computer: CPU board, floppy disk drive, power supply unit, etc.

7. Power module: inverter, solid state relay, rectifier bridge, etc.