TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The diameter of the point structure of the silicon wafer is 60-10 microns. The width of the strip structure is 60-10 microns. The positive conductive paste is silver aluminum paste. The silver aluminum paste comprises 80-90 wt.% silver, 0.3-8 wt.% aluminum powder, 0.1-10 wt.% inorganic glass powder, 1-15 wt.% oganic carrier, 0.1-10 wt.% organic additive and 0.01-5 wt.% other functional additives.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The inorganic glass powder is bismuth oxide-silicon dioxide-zinc oxide system, bismuth oxide-silicon dioxide-boron trioxide system, tellurium oxide-boron trioxide system, or bismuth oxide-tellurium oxide-silicon dioxide system. The bismuth oxide-silicon dioxide-zinc oxide system comprises 20-80 wt.% bismuth oxide, 5-20 wt.% silicon dioxide, 5-15 wt.% zinc oxide, 1-5 wt.% titanium oxide, 3-15 wt.% copper oxide, 1-25 wt.% manganese oxide, 0.5-50 wt.% tellurium oxide, 1-15 wt.% vanadium oxide, and 1-3 wt.% aluminum fluoride. The bismuth oxide-silicon dioxide-boron trioxide system comprises 20-80 wt.% bismuth oxide, 5-20 wt.% silicon dioxide, 2-15 wt.% boron trioxide, 5-15 wt.% zinc oxide, 1-5 wt.% titanium dioxide, 3-15 wt.% copper oxide, 1-25 wt.% manganese oxide, 0.5-50 wt.% tellurium oxide, 1-15 wt.% vanadium oxide, and 1-3 wt.% aluminum fluoride. The tellurium oxide-boron trioxide system comprises 25-50 wt.% tellurium oxide, 2-40 wt.% boron trioxide, 5-80 wt.% bismuth oxide, 5-20 wt.% silicon dioxide, 5-15 wt.% zinc oxide, 1-10 wt.% titanium oxide, 1-15 wt.% copper oxide, 1-15 wt.% manganese oxide, and 1-15 wt.% vanadium pentoxide. The bismuth oxide-tellurium oxide-silicon dioxide comprises 10-80 wt.% bismuth oxide, 10-50 wt.% tellurium oxide, 5-20 wt.% silicon dioxide, 5-15 wt.% zinc oxide, 1-10 wt.% titanium oxide, 1-15 wt.% copper oxide, 1-15 wt.% manganese oxide 1-15 wt.% vanadium pentoxide, and 1-15 wt.% lithium oxide. The silver paste comprises 75-91 wt.% silver, 0.1-10 wt.% inorganic glass powder, 1-25 wt.% organic carrier, 0.1-10 wt.% organic additive, and 0.01-5 wt.% other functional additives.    TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The aluminum powder is pure aluminum powder or aluminum alloy powder. The aluminum alloy powder is aluminum silicon alloy powder, aluminum-magnesium-silicon alloy powder or aluminum zinc alloy powder. The particle size of aluminum powder or aluminum alloy powder is smaller than 10 microns.