Microstructure, Mechanical, and Electrical Properties and Corrosion Analysis of Lead-Free Solder CSI Joints on Cu Substrate Using Novel Concentrated Solar Energy Soldering (CSES) Method

Table 4

Microhardness of CSES and CSI solder joints (before and after corrosion).

Solder material	CSES (before corrosion)		CSI (before corrosion)		CSES (after corrosion)		CSI (after corrosion)
	Microhardness (Hv)	Std devi.	Microhardness (Hv)	Std devi.	Microhardness (Hv)	Std devi.	Microhardness (Hv)	Std devi.
SAC305	14.98	0.1323	14.67	0.1843	12.82	0.2523	11.87	0.2393
SACX0307	12.86	0.1743	12.33	0.1943	11.78	0.2943	10.71	0.2993
99C	13.42	0.1933	13.19	0.1993	12.55	0.2433	11.83	0.2493
SnPb	12.92	0.1763	12.33	0.1863	11.07	0.2363	10.74	0.2393