MLC capacitors are MSL level 1 260☌ by construction and materials used. This is not the case for PC boards and plastic molded components that are moisture sensitive to water absorption of the plastics themselves. Those components limit time at temperature and number of solder cycles, not the MLCC.ĭue to the very nature and materials used in the manufacture of ceramic capacitors there are no moisture absorbing materials used nor are there critical interfaces within the MLCC that can crack or delaminate. The value temperature is generally 210-230, and the reflow time should not be too long to prevent adverse effects on SMA. Plastic molded components may crack or blister due to absorbed moisture. The board can blister, de-laminate and have plated thru hole failures. The maximum time at temperature, number of reflow solder cycles or re-work cycles are not limited by ceramic capacitors but by the assembly laminate and plastic molded components. The solder process needs to be controlled but no different that what is required for standard tin lead solder alloys. This does not mean that solder profiles can be ignored as there can be thermal shock cracking in wave soldering or during assembly cool down. There are no polymers or other temperature sensitive materials used minimizing the impact of increased soldering temperatures.Ĭeramic capacitors have been assembled without problems into leaded components for decades using high temperature solders that have melting points as high as 309☌ so lead free peak temperatures of 260☌ present no soldering temperature issues. Multi-layer ceramic capacitors (MLCC) do not have time and temperature limitations like plastic molded components due to the construction of those capacitors. Maximum number of assembly reflow cycles.The change to lead free soldering with its corresponding increase in soldering temperatures raises a number of assembly related process questions primarily because of plastic package limitations.
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