Chip capacitor welding requirements

What temperature can a chip capacitor withstand?

Chip capacitors can tolerate relatively high temperatures, by virtue of their processing, which typically involves a 1100°C to 1200°C firing of the dielectric body, followed with a second firing of the end metallization at approximately 850°C.

What temperature should a capacitor be cured?

Epoxies require a low temperature cure in the range of 25°C to 150°C. Wire bonding methods involve welding of very thin gold or aluminum wires to components, to effect an electrical connection; physical attachment of the capacitor body to the substrate must be made by other means, such as epoxy bonding.

Why do chip capacitors fail during the cooling cycle?

Chip capacitors are even more vulnerable to failure during the cooling cycle, as negative temperature gradients cause primarily tensile stress. Cooling must therefore be gradual and uniform, with no localized forced cooling or contact of the chip with any efficient heat sink.

Can multilayer ceramic capacitors be surface mounted to high-density boards?

Nowadays multilayer ceramic capacitors (MLCCs) are often sold as chip (or leadless) components that can be surface mounted to high-density boards using high speed automation. However, variables affecting attachment of chips to substrates are of increasing importance.

What is the thermal expansion coefficient of a chip capacitor?

Unfortunately, the thermal expansions of chip capacitors differ significantly from those of substrate materials. At 25°C to 300°C, capacitors typically range in expansion coefficient from 8.3 x 10-6 to 12.2 x 10-6 in/in/°C, while 99% Alumina is approximately 6.0 x 10-6 in/ in/°C and P.C. board is typically 16.0 x 10-6 in/in/°C.

What is capacitor fundamentals?

Welcome to the Capacitor Fundamentals Series, where we teach you about the ins and outs of chips capacitors – their properties, product classifications, test standards, and use cases – in order to help you make informed decisions about the right capacitors for your specific applications.