Typical application

• Wafer substrate for high-brightness LED

 

Selectable silicon/aluminum(Si/Al) alloy

• AlSi70(Si-30%Al controlled expansion alloy);

• AlSi80(Si-20%Al controlled expansion alloy).

 

 

Other applications of AlSi70 or AlSi80 alloy

• Microwave carrier for telecommunication;
• Cold plate material for high-energy solid state laser;

• Photovoltaic(PV) cells.

 

Alternative material

• Al₂O₃;
• Copper-molybdenum(Cu-Mo).

 

Main benefits

• CTE close to that of arsenic gallium(GaAs) and Sapphire;

• High thermal conductivity;

• Thermal stability;

• Readily machining and eletroless plating(e.g.Ni/Au);

• Wafer diameter can be achieved by 300mm and polishing to 10nm Ra.

 

AlSi Alloys Performance Parameters

 

Content wt%	Density   g/cm³	CTE  25℃  ppm/℃	Thermal  Conductivity 25℃ W/mK	Tensile  Strength    MPa	Yield  Strength    MPa	Poisson’s  Ratio	Elongation %	Elastic Modulus  GPa
Al-27%Si	2.6	17	175	170	130	0.29	3.8	91
Al-42%Si	2.55	13.5	143	200	187	0.29	1	105
Al-50%Si	2.5	11.5	140	200	210	0.28	<1	108
Si-40%Al	2.46	9	125	181	181	0.27	<1	121
Si-30%Al	2.43	7.5	120	138	138	0.25	<1	131
Si-20%Al	2.40	6	110	125	125	--	--	132