The relationship between crack initiation tendency before chemical strengthening and fracture strength of chemically strengthened glass was investigated. Four kinds of glass compositions were used in this study: soda-lime silicate (SLS), aluminosilicate (ALS-1, ALS-2), and aluminoborosilicate (ALBS) glasses. The fracture strength of sheet glass was measured by the four-point bending test, the ring-on-ring test, the ball drop test, and the predamaged four-point bending test. ALBS glass, which has the lowest crack formation probability before chemical strengthening, is more damage tolerant than other glasses, and one of the best candidates for chemical strengthening.

It is well known that bus electrode plays a main role in series resistance of solar cells. Bus electrodes composed of the bare leads, of which thermal expansion coefficients are less than cell's, coated with highly conducting metals were investigated. These leads exhibited the lower expansion coefficient than expected by the empirical law, and the origins of these phenomena were explained. Work hardening effect on expansion coefficient was then measured. Solar cell fabrication with these leads and rigid solders rationalized assembly processing. Cell characteristics proved to be excellent compared with conventional ones. Finally, lead costs were compared for various materials.