Soft termination

“Flex Crack” and “Thermal Shock Crack” are the most serious extrinsic defects of MLCC except for intrinsic defects derived from MLCC manufacturing process. There are a few methods to overcome this issue. “Soft termination (metal-epoxy)” technique is one of the most effective method, which can minimize flex and thermal shock crack.

FM can provide various high-quality pastes for soft termination; Ag-epoxy (AST-series), Ag/Cu-epoxy (ACST-series), and Cu-epoxy (CST-series).

FM’s pastes for soft termination have the following merits.

- Easy work and store
: They have very stable viscosity at room temperature, so they can be stored and used at room temperature.
- Low elastic modulus and high flex strength
- Strong adhesion and heat-resistance
: After solder heat test at 290℃ for 10sec., there is no peeling or crack.
- Good plating quality
: CST series as well as AST and ACST series can give good plating quality.
- Good electrical contact similar as normal Cu termination
- Better MLCC reliability

	AST-series	ACST-series	CST-series
Metal	Ag	Ag-coated Cu	Cu
Metal Content	> 70%
Curing condition	@ 180 ~ 210℃ for more than 2 hours
Viscosity	5,000 ~ 30,000 cps (@ 10rpm, SC4-#14 spindle)
Resistivity	< 2.0*10-4 Ohm∙cm	< 2.0*10-4 Ohm∙cm	< 1.0*10-1 Ohm∙cm